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1

Cytological identification of cell types in the testis of Esox lucius and E. niger  

Microsoft Academic Search

Testes of Esox lucius and Esox niger were investigated histologically, cytochemically, and ultrastructurally in reproductive fish. Intralobular Sertoli cells possessed numerous lipid droplets in Esox lucius, but not in Esox niger. In both species, interlobular cell types included myoid cells and lipid-negative Leydig cells within the extravascular space. Evidence is presented for a contractile network of myoid cells within the

H. J. Grier; R. Hurk; R. Billard

1989-01-01

2

Pike Hybrids (Esox lucius x E. vermiculatus) in a Sandhill Lake, Nebraska  

Microsoft Academic Search

In the sandhill region of Nebraska both northern pike, Esox lucius, and grass pickerel, Esox vermiculatus, are abundant in several shallow natural lakes. Both species are known to utilize the same vegetative habitat for spawning during March and April. The pike is an important game species but the smaller pickerel is of little value to fishermen although in winter is

D. B. McCarraher

1960-01-01

3

Ovarian alterations in wild northern pike Esox lucius females.  

PubMed

The aim of the present study was to analyse the occurrence of macroscopically visible ovary alterations in 2 populations of northern pike Esox lucius L. originating from lakes in the Mazurian Lake District (NE Poland). The alterations were characterised by ovary tissue that was morphologically malformed, in part or in whole, and contained immature oocytes, i.e. trophoplastic or previtellogenic oocytes instead of vitellogenic oocytes. These alterations were found only in the ovaries, and no morphological alterations of the testes were noted. Macroscopic and histological analyses were carried out in order to classify the observed alterations in the ovaries. Three types of alterations were identified in which morphological malformations as well as histological investigation of the ovaries were considered. An analysis of the size and age of the fish in relation to the occurrence of alterations as well as of the macroscopic and histological nature of the alteration types was made. The data obtained revealed no lake or age dependency of the observed alterations. Based on the results obtained, we suggest that the presence of endocrine disruptors in the environment or/and genetic factors could be responsible for these kinds of gonad anomalies. However, our results did not allow us to determine the aetiology of the alterations. PMID:24062552

Zarski, Daniel; Rechulicz, Jacek; Krejszeff, S?awomir; Czarkowski, Tomasz K; Sta?czak, Katarzyna; Pali?ska, Katarzyna; Gryzi?ska, Magdalena; Targo?ska, Katarzyna; Koz?owski, Krzysztof; Mamcarz, Andrzej; Hliwa, Piotr

2013-09-24

4

MERCURY LEVELS IN NORTHERN PIKE, ESOX LUCIUS, RELATIVE TO WATER CHEMISTRY IN NORTHERN MINNEOSTA LAKES  

Microsoft Academic Search

Previous studies on lakes in northern Minnesota revealed elevated fish mercury concentrations. These results prompted fish consumption advisories on several lakes. As a followup to that work, fish fillet samples were collected for mercury analysis from 98 lakes in northern Minnesota from 1981 through 1983. Northern pike (Esox lucius) was picked as an indicator species because of its distribution throughout

Steven A. Heiskary; Daniel D. Helwig

1986-01-01

5

Behaviour and survival of pike, Esox lucius, with a retained lure in the lower jaw  

Microsoft Academic Search

The behaviour and survival of pike, Esox lucius L., released with a retained lure in the mouth was studied relative to control fish, which simulated line breakage prior to landing. Behaviour was monitored during the first hour post-release with the aid of visual floats attached to the fish, and longer-term for 3 weeks, by means of externally attached radio transmitters.

R. A RLINGHAUS; A. J. G INGERICH; M. R. DONALDSON; K. C. H ANSON; S. J. C OOKE

2008-01-01

6

Chemical labeling of northern pike ( Esox lucius ) by the alarm pheromone of fathead minnows ( Pimephales promelas )  

Microsoft Academic Search

In previous experiments, chemical stimuli from northern pike (Esox lucius) elicited fright responses from pike-naive fathead minnows (Pimephales promelas) only if the pike had recently eaten conspecific minnows. We used a behavioral assay to determine if the fright response is the result of the incorporation of the minnow alarm pheromone into the chemical signature of the pike. Because the alarm

Alicia Mathis; R. Jan F. Smith

1993-01-01

7

Age and Growth of Pike ( Esox lucius) in Chivyrkui Bay, Lake Baikal  

Microsoft Academic Search

The purpose of this study was to describe age and growth of pike (Esox lucius) in Lake Baikal. Pike were collected with gill nets and by angling in Chivyrkui Bay in late July-early August 1993 and by gill nets in June 1995. Total length (mm), weight (g), and sex were recorded and scales and cleithra were collected for aging. In

Randall W. Owens; Nikolai M. Pronin

2000-01-01

8

Standard metabolic rate of pike, Esox lucius : variation among studies and implications for energy flow modelling  

Microsoft Academic Search

The pike, Esox lucius Linnaeus, is a predatory fish that supports important fisheries and could substantially impact prey populations around the\\u000a temperate northern hemisphere. Consumption of prey by pike is most readily estimated using the energy budget to calculate\\u000a food intake indirectly using estimates of growth rate and metabolism. Resting metabolic rate, R\\u000a s, is a particularly important component of

John D. Armstrong; Lorraine A. Hawkins

2008-01-01

9

Biomarkers of Contaminant Exposure in Northern Pike ( Esox lucius ) from the Yukon River Basin, Alaska  

Microsoft Academic Search

As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with\\u000a organochlorine pesticide (total p,p’-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic,\\u000a cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite

J. E. Hinck; V. S. Blazer; N. D. Denslow; M. S. Myers; T. S. Gross; D. E. Tillitt

2007-01-01

10

A quantitative comparison between diet and body fatty acid composition in wild northern pike ( Esox lucius L.)  

Microsoft Academic Search

The fatty acid compositions of wild female northern pike (Esox lucius L.) and their principle prey species were compared to assess the extent to which pike modify the relative abundance of dietary fatty acids during assimilation and to indicate the optimum dietary content of essential fatty acids (EFAs) for pike. Only minor differences existed between the estimated whole body fatty

Karl Schwalmel

1992-01-01

11

ENDOCRINE (SEXUAL) DISRUPTION IS NOT A PROMINENT FEATURE IN THE PIKE (ESOX LUCIUS), A TOP PREDATOR, LIVING IN ENGLISH WATERS  

Microsoft Academic Search

The high incidence of intersex roach ( Rutilus rutilus) in some United Kingdom rivers that has been associated with exposure to sewage treatment works (STWs) effluent led us to hypothesize that top predator fish also may be affected by estrogenic chemicals, because they are likely to bioaccumulate lipophilic compounds through a predator-prey relationship. To investigate this possibility, pike (Esox lucius)

Emma Vine; Jan Shears; Ronny van Aerle; Charles R. Tyler; John P. Sumpter

2005-01-01

12

Spatial genetic structure of northern pike (Esox lucius) in the Baltic Sea.  

PubMed

The genetic relationships among 337 northern pike (Esox lucius) collected from the coastal zone of the central Baltic region and the Finnish islands of Aland were analysed using five microsatellite loci. Spatial structure was delineated using both traditional F-statistics and individually based approaches including spatial autocorrelation analysis. Our results indicate that the observed genotypic distribution is incompatible with that of a single, panmictic population. Isolation by distance appears important for shaping the genetic structure of pike in this region resulting in a largely continuous genetic change over the study area. Spatial autocorrelation analysis (Moran's I) of individual pairwise genotypic data show significant positive genetic correlation among pike collected within geographical distances of less than c. 100-150 km (genetic patch size). We suggest that the genetic patch size may be used as a preliminary basis for identifying management units for pike in the Baltic Sea. PMID:15910318

Laikre, Linda; Miller, Loren M; Palmé, Anna; Palm, Stefan; Kapuscinski, Anne R; Thoresson, Gunnar; Ryman, Nils

2005-06-01

13

Pike (Esox lucius L.) stocking as a biomanipulation tool 1. Effects on the fish population in Lake Lyng, Denmark  

Microsoft Academic Search

From 1990–1993 juvenile pike (Esox lucius) were stockedeach spring in the eutrophic Lake Lyng (9.9 ha, max. depth 7.6 m,mean depth 2.4 m) in densities between 515 and 3616 pikeha-1. In 1989–90 the fish population consisted mainly ofroach (Rutilus rutilus), rudd(Scardinius erythrophthalmus), perch (Percafluviatilis) and ruffe (Gymnocephalus cernuus), andtotal fish biomass was estimated at 477 kg ha-1. Prior tostocking pike

Søren Berg; Erik Jeppesen; Martin Søndergaard

1997-01-01

14

Light, fluorescence, and electron microscopic studies on the pineal organ of the pike, Esox lucius L., with special regard to 5-hydroxytryptamine  

Microsoft Academic Search

The pineal organ of adult pikes, Esox lucius L., maintained under normal diurnal conditions, was studied with a combination of light microscopy, fluorescence histochemistry of certain arylethylamines, and electron microscopy.1.The pineal parenchyma consists of sensory cells, supporting cells, and a third cell type which may be identical with previously described ganglion cells. The nerve fibres constituting the pineal tract were

Christer Owman; Claes Rüdeberg

1970-01-01

15

Biomarkers of contaminant exposure in Northern Pike (Esox lucius) from the Yukon River Basin, Alaska.  

PubMed

As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P < 0.01). Vitellogenin concentrations in female (0.09 to 5.32 mg/mL) and male (<0.0005 to 0.097 mg/mL) pike were not correlated with any contaminant, but vitellogenin concentrations >0.01 mg/mL in male pike from multiple sites indicated exposure to estrogenic compounds. Mean steroid hormone concentrations and percent oocyte atresia were not anomalous in pike from any YRB site. Few site differences were significant for mean MA density (1.86 to 6.42 MA/mm(2)), size (812 to 1481 microm(2)), and tissue occupied (MA-%; 0.24% to 0.75%). A linear regression between MA-% and total PCBs was significant, although PCB concentrations were generally low in YRB pike (< or =63 ng/g), and MA-% values in female pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship. Histological abnormalities observed in gill, liver, spleen, and kidney tissues were not likely a result of contaminant exposure but provide information on the general health of YRB pike. The most common histologic anomalies were parasitic infestations in various organs and developing nephrons and nephrocalcinosis in posterior kidney tissues. Overall, few biomarker responses in YRB pike were correlated with chemical contaminant concentrations, and YRB pike generally appeared to be healthy with no site having multiple anomalous biomarker responses. PMID:17396212

Hinck, J E; Blazer, V S; Denslow, N D; Myers, M S; Gross, T S; Tillitt, D E

2007-03-29

16

The state of reproductive glands of the pike Esox lucius from water bodies of the Chernobyl trail in 1999–2004  

Microsoft Academic Search

The state of the reproductive system of the pike Esox lucius, descendants of individuals exposed to X-ray irradiation due to the catastrophe at the Chernobyl Nuclear Power Plant in 1986,\\u000a was studied. The material was collected in water bodies of Ukraine contaminated with radionuclides—Kiev Reservoir, the Teterev\\u000a River, and Lake Glubokoe in the postcatastrophe period 1999–2004. It was shown that

N. V. Belova; N. G. Eme’lynova; A. P. Makeeva; I. N. Ryabov

2006-01-01

17

[Taxonomic characteristics and physiological properties of microorganisms from the gut of pike (Esox lucius)].  

PubMed

The taxonomic composition and distribution of microorganisms differing in the degree of association with the intestinal mucosa of the pike (Lucius lucius) has been studied. Microorgansism of the families Enterobacteriaceae, Aeromonadaceae, and Vibrionaceae dominate in the gut microflora. Numerically prevailing bacterial species are characterized by high proteolytic and amylolytic enzyme activities as well as by high persistence accounted for by antilysozyme and antihistone activities. The results of this study show that Hafnia alvei, Yersinia ruckeri, Vibrio vulnificus, V. furnissii, Aeromonas salmonicida, and Shewanella putrefaciens may be regarded as normal components of the pike gut microflora. PMID:19198074

Izveskova, G I; Nemtseva, N V; Plotnikov, A O

18

Quantifying selection differentials caused by recreational fishing: development of modeling framework and application to reproductive investment in pike (Esox lucius)  

PubMed Central

Methods for quantifying selection pressures on adaptive traits affected by size-selective fishing are still scarce, and none have as yet been developed for recreational fishing. We present an ecologically realistic age-structured model specifically tailored to recreational fishing that allows estimating selection differentials on adaptive life-history traits. The model accounts for multiple ecological feedbacks, which result in density-dependent and frequency-dependent selection. We study selection differentials on annual reproductive investment under size-selective exploitation in a highly demanded freshwater recreational fish species, northern pike (Esox lucius L.). We find that recreational angling mortality exerts positive selection differentials on annual reproductive investment, in agreement with predictions from life-history theory. The strength of selection increases with the intensity of harvesting. We also find that selection on reproductive investment can be reduced by implementing simple harvest regulations such as minimum-size limits. The general, yet computationally simple, methods introduced here allow evaluating and comparing selection pressures on adaptive traits in other fish populations and species, and thus have the potential to become a tool for evolutionary impact assessment of harvesting.

Arlinghaus, Robert; Matsumura, Shuichi; Dieckmann, Ulf

2009-01-01

19

Endocrine (sexual) disruption is not a prominent feature in the pike (Esox lucius), a top predator, living in English waters.  

PubMed

The high incidence of intersex roach (Rutilus rutilus) in some United Kingdom rivers that has been associated with exposure to sewage treatment works (STWs) effluent led us to hypothesize that top predator fish also may be affected by estrogenic chemicals, because they are likely to bioaccumulate lipophilic compounds through a predator-prey relationship. To investigate this possibility, pike (Esox lucius) were sampled both upstream and downstream of STWs and then examined for total estrogenic activity of their bile, as measured using a yeast-based estrogen assay to determine the degree of recent exposure of the pike to estrogens and vitellogenin induction, and for possible disruption of sexual development, as measured using histological analysis of the gonads. No evidence of severe disruption was found in the sampled fish, which came from 16 sampling sites that were representative of English rivers. However, 14% of pike were intersex, of which 15 of 16 showed patches of male germ cells among predominantly female gonadal tissue. The incidence of masculinization was independent of whether the pike had been sampled upstream or downstream of STWs. Although pike are gonochoristic, it is not known if this masculinization of presumptive female pike is normal or, instead, indicative of endocrine disruption. Vitellogenin concentrations were not elevated in male pike at sites either upstream or downstream of STWs. The results suggest that sexual disruption is not common in pike, a fish at the top of the food chain in the freshwaters of England. PMID:16117120

Vine, Emma; Shears, Jan; van Aerle, Ronny; Tyler, Charles R; Sumpter, John P

2005-06-01

20

Dietary uptake in pike (Esox lucius) of some polychlorinated biphenyls, polychlorinated naphthalenes and polybrominated diphenyl ethers administered in natural diet  

SciTech Connect

The dietary uptake of 12 halogenated diaromatic compounds was studied using northern pike (Esox lucius L.) fed with rainbow trout (Oncorhynchus mykiss (Walbaum)). Before the trout were fed to the pike, they had been injected with a cocktail of five polychlorinated biphenyls, four polychlorinated naphthalenes, and three polybrominated diphenyl ethers, dissolved in rainbow trout lipid. The reported uptake efficiencies (E) were in the range 35 to 90% and differ in some respect from earlier studies. The E-values for those substances with effective cross sections (ECS) >9.5 {angstrom} were considerably higher than expected if the membrane permeation at dietary uptake was restricted as proposed previously in the literature. There was no hydrophobicity dependency of the total dietary uptake efficiency as suggested by an earlier proposed empirical model. The difference between the results presented here and earlier studies is likely to depend on cotransport with lipids and/or proteins through a mediated, possibly active uptake of hydrophobic organic compounds (HOC) in the gastrointestinal tract enabled by the actual exposure method. For the proposed mediated/active uptake of HOCs, the uptake efficiency varied with molecular weight and was greatest for a molecular weight of approximately 450.

Burreau, S.; Axelman, J.; Broman, D.; Jakobsson, E. [Stockholm Univ. (Sweden)

1997-12-01

21

Spatial analysis of Cd and Pb in the Pike (Esox lucius) from Western Anzali wetlands of Iran.  

PubMed

Geostatistical studies are used to estimate pollution burden in aquatic ecosystems and to plan large-scale control programs to protect these environments. Geostatistical studies allow us to predicted pollutant concentrations for areas that have not been sampled. This is done by taking into account the spatial correlations between estimated and sampled points and by minimizing the variance of estimation error. The use of geostatistical techniques in biomonitoring of fish species can illuminate extent and source of pollution, thereby providing an effective tool for developing intervention strategies to protect such environments. This study investigates the spatial distribution patterns of cadmium and lead in the Pike (Esox lucius). Fish were captured in the western parts of the Anzali wetlands located on the Caspian Sea in Iran. The muscle tissue of Anzali Pike had 5 ± 0.25 and 168 ± 18.4 (ng/g dw) cadmium and lead, respectively. Positive relationships were detected between Pike's length and weight (r = 0.85, p < 0.05), length and age (r = 0.35, p < 0.05), and muscle cadmium and lead (r = 0.45, p < 0.05). By contrast, there was a negative relationship between lead levels and weight in Pike (r = -0.36, p < 0.05). For both metals, the resulting metal concentration maps indicated higher pollutant concentrations in the southeast parts of the study area. Considerable boat traffic activity and agricultural activity contribute to the pollution in these areas, undermining the integrity of local habitat for fish survival and reproduction. PMID:23292487

Zamani-Ahmadmahmoodi, R; Esmaili-Sari, A; Mohammadi, J; Riyahi Bakhtiari, A; Savabieasfahani, M

2013-01-05

22

Salmo salar and Esox lucius full-length cDNA sequences reveal changes in evolutionary pressures on a post-tetraploidization genome  

PubMed Central

Background Salmonids are one of the most intensely studied fish, in part due to their economic and environmental importance, and in part due to a recent whole genome duplication in the common ancestor of salmonids. This duplication greatly impacts species diversification, functional specialization, and adaptation. Extensive new genomic resources have recently become available for Atlantic salmon (Salmo salar), but documentation of allelic versus duplicate reference genes remains a major uncertainty in the complete characterization of its genome and its evolution. Results From existing expressed sequence tag (EST) resources and three new full-length cDNA libraries, 9,057 reference quality full-length gene insert clones were identified for Atlantic salmon. A further 1,365 reference full-length clones were annotated from 29,221 northern pike (Esox lucius) ESTs. Pairwise dN/dS comparisons within each of 408 sets of duplicated salmon genes using northern pike as a diploid out-group show asymmetric relaxation of selection on salmon duplicates. Conclusions 9,057 full-length reference genes were characterized in S. salar and can be used to identify alleles and gene family members. Comparisons of duplicated genes show that while purifying selection is the predominant force acting on both duplicates, consistent with retention of functionality in both copies, some relaxation of pressure on gene duplicates can be identified. In addition, there is evidence that evolution has acted asymmetrically on paralogs, allowing one of the pair to diverge at a faster rate.

2010-01-01

23

DNA adduct formation and persistence in liver and extrahepatic tissues of northern pike (Esox lucius) following oral exposure to benzo[a]pyrene, benzo[k]fluoranthene and 7H-dibenzo[c,g]carbazole.  

PubMed

The formation and persistence of DNA adducts in liver, intestinal mucosa, gills and brain of juvenile northern pike (Esox lucius) following oral exposure to benzo[a]pyrene (BaP), benzo[k]fluoranthene (BkF) and 7H-dibenzo[c,g]carbazol (DBC) were analysed by 32P-postlabelling. The dosage was 25 micromol/kg body weight of each substance, administered on 5 occasions with an interval of 12-14 days. Sampling was carried out 9 days after the second treatment, and 9, 16, 33 and 78 days after the fifth treatment. Pikes were also fed with the substances singly for comparison of adduct patterns. A complex pattern of adducts was detected in all examined tissues from fish treated with the mixture. Total adduct levels were highest in intestine (347+/-17.4 nmol adducts/mol nucleotides, mean+/-SE), followed by liver (110+/-9.3), gills (69+/-6) and brain (14+/-4.2). In pike treated with BaP alone, one major adduct was detected in all examined tissues. This BaP-adduct made up approximately 50% of the total amount of adducts in the brain. Corresponding values in liver, intestine and gills were 23, 31 and 34%, respectively. One relatively weak BkF-adduct and at least 10 different DBC-adducts were detected in all analysed tissues. Total adduct level in the intestine declined to 29.4% of the maximum value 78 days after the last exposure, while there was no significant decline in adduct levels in liver, gills or brain. The results suggest that intestine is more susceptible to adduct formation than liver after oral exposure, and that adduct levels in the intestine represent ongoing or relatively recent exposure. DNA adducts in the other investigated tissues were much more persistent and may therefore accumulate during long-term exposure. PMID:10393267

Ericson, G; Noaksson, E; Balk, L

1999-06-30

24

Development of new microsatellite loci and multiplex reactions for muskellunge (Esox masquinongy)  

USGS Publications Warehouse

The muskellunge (Esox masquinongy) is a valued fisheries species throughout its native range. Numerous studies have documented performance and phenotypic differences among muskellunge populations, but genetic markers for assessment have been lacking. We characterized 14 microsatellite loci and developed five multiplex polymerase chain reactions. Successful amplification of northern pike (Esox lucius) was observed for seven loci. These microsatellites will be useful for analysing population structure, performance characteristics of propagated strains, and helping to develop and monitor hatchery management guidelines for muskellunge. ?? 2008 Blackwell Publishing Ltd.

Sloss, B. L.; Franckowiak, R. P.; Murphy, E. L.

2008-01-01

25

Mercury pollution and macrophage centres in pike ( Esox lucius ) tissues  

Microsoft Academic Search

From June 1993 to October 1994, studies have been carried out on the effects of mercury in the Oder River and pike tissue\\u000a contamination (muscle, kidney, liver). The mean mercury contents in the sediment range from 0.03 to 1.1 mg\\/kg dry weight.\\u000a In the pike muscle, between 0.22 and 0.85 mg\\/kg, on a wet weight basis, were found. The measured

Thomas Meinelt; Ralf Kriiger; Michael Pietrock; Reiner Osten; Christian Steinberg

1997-01-01

26

Molecular and Phenotypic Evidence of a New Species of Genus Esox (Esocidae, Esociformes, Actinopterygii): The Southern Pike, Esox flaviae  

PubMed Central

We address the taxonomic position of the southern European individuals of pike, performing a series of tests and comparisons from morphology, DNA taxonomy and population genetics parameters, in order to support the hypothesis that two species of pike, and not only one, exist in Europe. A strong relationship emerged between a northern genotype supported by COI, Cytb, AFLP and specific fragments, and a phenotype with round spot skin colour pattern and a large number of scales in the lateral line, clearly separated from a southern genotype with other skin colour pattern and a low number of scales in the lateral line. DNA taxonomy, based on a coalescent approach (GMYC) from phylogenetic reconstructions on COI and Cytb together with AFLP admixture analysis, supported the existence of two independently evolving entities. Such differences are not simply due to geographic distances, as northern European samples are more similar to Canadian and Chinese samples than the southern Europe ones. Thus, given that the differences between the two groups of European pike are significant at the phenotypic, genotypic and geographical levels, we propose the identification of two pike species: the already known northern pike (Esox lucius) and the southern pike (E. flaviae n.sp.). The correct identification of these two lineages as independent species should give rise to a ban on the introduction of northern pikes in southern Europe for recreational fishing, due to potential problems of hybridisation.

Lucentini, Livia; Puletti, Maria Elena; Ricciolini, Claudia; Gigliarelli, Lilia; Fontaneto, Diego; Lanfaloni, Luisa; Bilo, Fabiana; Natali, Mauro; Panara, Fausto

2011-01-01

27

Food of Young Pike, Esox Lucius L., and Associated Fishes in Peterson's Ditches, Houghton Lake, Michigan  

Microsoft Academic Search

Stomach contents of 551 young pike (11–152 millimeters in length), 345 small yellow perch, and 431 other fish representing 18 species were examined. All specimens were collected from an area widely used by spawning pike from Houghton Lake, Michigan. Organisms utilized for food by young pike included Entomostraca, insects (chiefly Chironomidae), tadpoles, minnows, darters, and other pike. As pike increased

Burton P. Hunt; William F. Carbine

1951-01-01

28

Determination of polychlorinated biphenyls and total mercury in two fish species ( Esox lucius and Carassius auratus ) in Anzali Wetland, Iran  

Microsoft Academic Search

The Anzali Wetland is one of the most important ecosystems in the north of Iran, and parts of it were registered as a Ramsar\\u000a site in 1975. However, even though, due to many problems, including eutrophication produced by inflow of excess nutrients\\u000a and organic materials, the wetland was also listed on the Montreux Record indicating the need to take urgent

Mohammad Sakizadeh; Abas Esmaeili Sari; Asghar Abdoli; Nader Bahramifar; Seyed Hossein Hashemi

29

The influence of angling-induced exercise on the carbohydrate metabolism of northern pike ( Esox lucius L.)  

Microsoft Academic Search

Summary  Capture by angling was used to induce burst exercise in northern pike. By 3 h after exercise blood lactate had risen to levels\\u000a of 15.2 mmol l?1 (Fig. 2), which greatly exceeded the maximum post-exercise levels (4.0 mmol l?1) previously reported for muskellunge, a close relative of pike. White muscle lactate level was high, 41.8 mmol kg?1, immediately after capture

K. Schwalme; W. C. Mackay

1985-01-01

30

A toxicological examination of whitefish (Coregonus clupeaformis) and northern pike (Esox lucius) exposed to uranium mine tailings.  

PubMed

Operation of the Gunnar uranium mine, in nothern Saskatchewan, Canada, from 1955 to 1964, resulted in the deposition of radioactive tailings in Langley Bay, a small bay connected to Lake Athabasca. Previous publications have described the contamination of the sediments, water, macrophytes and fish of this area. The present study compares the parasite infestations, blood hematocrit, histopathology and condition factor (K) of the Langley Bay whitefish and northern pike populations with these factors measured for control populations from Lake Athabasca. No significant differences could be found, in any of the physiological parameters measured, between the contaminated and control populations. PMID:2386411

Waite, D T; Joshi, S R; Sommerstad, H; Wobeser, G; Gajadhar, A A

31

Ultrastructure of atrial and ventricular myocardium in the pike Esox lucius L. and mackerel Scomber scombrus L. (pisces).  

PubMed

Atrial and ventricular muscle in the pike and mackerel hearts consists of narrow, branching cells. The atrial cells in the two species are similar whereas the ventricular cells differ. The sarcolemma is attached to the Z and M lines of the sarcomere. Intercalated discs are common, and the transverse parts display desmosomes and intermediate junctions. Nexuses are uncommon and only occur in the longitudinal parts of the intercalated discs. The sarcoplasmic reticulum forms a regular hexagonal network on the myofibrillar surface. Subsarcolemmal cisternae form peripheral couplings at the I--A level. Junctional processes are usually inconspicuous, but an electron dense substance is present between the sarcolemma and the junctional sarcoplasmic reticulum. Specific heart granules are common in atrial cells of both species and in ventricular cells of the pike, but are very scarce in mackerel ventricular muscle. PMID:7407886

Midttun, B

1980-01-01

32

Historical analysis of genetic variation reveals low effective population size in a northern pike (Esox lucius) population.  

PubMed

Effective population size (Ne) of a natural fish population was estimated from temporal changes in allele frequencies at seven microsatellite loci. Use of a historical collection of fish scales made it possible to increase the precision of estimates by increasing the time interval between samples and to use an equation developed for discrete generations without correcting for demographic parameters. Estimates of Ne for the time intervals 1961-1977 and 1977-1993 were 35 and 72, respectively. For the entire interval, 1961-1993, the estimate of Ne was 48 when based on a weighted mean derived from the above two estimates or 125 when calculated from 1961 and 1993 samples only. Corresponding ratios of effective size to adult census size ranged from 0.03 to 0.14. An Ne of 48 over a 32-year period would imply that this population lost as much as 8% of its heterozygosity in that time. Results suggest the potential for using genetic methods based on microsatellite loci data to compare historical trends in Ne with population dynamic parameters. Such comparisons will help to evaluate the relationship between genetic diversity and long-term persistence of natural populations. PMID:9383067

Miller, L M; Kapuscinski, A R

1997-11-01

33

Historical Analysis of Genetic Variation Reveals Low Effective Population Size in a Northern Pike (Esox Lucius) Population  

PubMed Central

Effective population size (N(e)) of a natural fish population was estimated from temporal changes in allele frequencies at seven microsatellite loci. Use of a historical collection of fish scales made it possible to increase the precision of estimates by increasing the time interval between samples and to use an equation developed for discrete generations without correcting for demographic parameters. Estimates of N(e) for the time intervals 1961-1977 and 1977-1993 were 35 and 72, respectively. For the entire interval, 1961-1993, the estimate of N(e) was 48 when based on a weighted mean derived from the above two estimates or 125 when calculated from 1961 and 1993 samples only. Corresponding ratios of effective size to adult census size ranged from 0.03 to 0.14. An N(e) of 48 over a 32-year period would imply that this population lost as much as 8% of its heterozygosity in that time. Results suggest the potential for using genetic methods based on microsatellite loci data to compare historical trends in N(e) with population dynamic parameters. Such comparisons will help to evaluate the relationship between genetic diversity and long-term persistence of natural populations.

Miller, L. M.; Kapuscinski, A. R.

1997-01-01

34

Northern pike ( Esox lucius L.) and aquatic vegetation, tools in the management of fisheries and water quality in shallow waters  

Microsoft Academic Search

Species and size composition of fish communities in shallow stagnant waters appear to be associated with the type, abundance and pattern of the vegetation. Man-induced impacts as eutrophication, and suppression of vegetation for reasons of water quantity management or angling pleasure may induce irreversible changes in the aquatic ecosystem. Water quality management should aim at restoring former pike habitat. Submerged

M. P. Grimm

1989-01-01

35

A toxicological examination of whitefish ( Coregonus clupeaformis ) and northern pike ( Esox lucius ) exposed to uranium mine tailings  

Microsoft Academic Search

Operation of the Gunnar uranium mine, in northern Saskatchewan, Canada, from 1955 to 1964, resulted in the deposition of radioactive tailings in Langley Bay, a small bay connected to Lake Athabasca. Previous publications have described the contamination of the sediments, water, macrophytes and fish of this area. The present study compares the parasite infestations, blood hematocrit, histopathology and condition factor

D. T. Waite; S. R. Joshi; H. Sommerstad; G. Wobeser; A. A. Gajadhart

1990-01-01

36

Retinal projections in the chain pickerel ( Esox niger Lesueur)  

Microsoft Academic Search

Summary The retinal projections inEsox niger, as determined with the aid of a modified cobalt-lysine method, are considerably more extensive in the diencephalon and pretectum than in other teleost fishes so far examined. Although most retinal axons terminate contralaterally, rare fibers can be traced to the same aggregates ipsilaterally. The retinohypothalamic projection appears larger than hitherto reported in teleosts, and

G. T. Bazer; S. O. E. Ebbesson

1987-01-01

37

Occurrence of 'Esox niger' in Santa Rosa Sound, Florida.  

National Technical Information Service (NTIS)

This is the first report of Esox niger collected from the normally saline portion of the lower Pensacola estuary. A 109 mm standard length chain pickerel was seined on 7 August 1975 from Santa Rosa Sound, in Santa Rosa County, Florida, from Thalassia beds...

L. R. Goodman

1977-01-01

38

Gyrodactylus neili n. sp. (Monogenea: Gyrodactylidae), a parasite of chain pickerel Esox niger Lesueur (Esocidae) from freshwaters of New Brunswick, Canada.  

PubMed

Gyrodactylus neili n. sp. (Monogenea: Gyrodactylidae) is described from the fins and body surface of Esox niger Lesueur (chain pickerel) (Esocidae) from the St. Croix River drainage, New Brunswick, Canada. G. neili n. sp. resembles most closely G. fryi Cone & Dechtiar, 1984, a parasite of E. masquinongy in North America, in having relatively large thin hamuli, well-developed marginal hook sickles with a relatively long, wide blade and short handle, a ventral bar with small antero-lateral processes and tongue-shaped membrane, and a cirrus with many small spines in two rows. The new species is easily separated from G. fryi by the length of the hamuli (70-76 microm versus 92 microm, respectively), by the distal width of the sickle (7-9 versus 14-16 microm, respectively) and by subtle differences in the shape of the toe and heel of the marginal hook sickle. Sequence data (922 bp) of rDNA (internal transcribed spacers 1 and 2 and 5.8S) of G. neili n. sp. returned no identical matches in GenBank. The 5.8 sequence alone, however, was identical to morphologically similar gyrodactylids of the subgenus Gyrodactylus from cyprinid fishes in Eurasia. The discovery of G. neili n. sp. and features of its genetic makeup support the idea that this lineage parasitised ancestral cyprinids and that it radiated, possibly through predator/prey interactions, to an ancestor of contemporary Esox. It is concluded that DNA comparison of monogeneans on Holarctic freshwater hosts, such as E. lucius, may shed light on the nature of speciation of these parasites. PMID:16773231

LeBlanc, Jaclyn; Hansen, Haakon; Burt, Michael; Cone, David

2006-05-05

39

Reproduction and Early Life History of the Redfin Pickerel, (Esox americanus americanus).  

National Technical Information Service (NTIS)

The reproductive strategy of the redf in pickerel (Esox americanus americanus) in a blackwater system in Sumter County, South Carolina was studied using daily aging techniques derived from otolith analysis. The presence of biannual spawning, a significant...

M. S. Ballek

1994-01-01

40

What do the empty stomachs of northern pike ( Esox lucius ) reveal? Insights from carbon (? 13 C) and nitrogen (? 15 N) stable isotopes  

Microsoft Academic Search

The frequency of individuals with empty stomachs (FES) can vary greatly among northern pike populations. However, the FES\\u000a has only seldom been analyzed in this species and its meaning is still not fully understood. It has been suggested that a\\u000a high FES may reflect a strongly piscivorous behaviour while low FES could reflect a higher utilization of invertebrates. We\\u000a compared

Yves Paradis; Andrea Bertolo; Pierre Magnan

2008-01-01

41

Production, consumption and prey availability of northern pike ( Esox lucius ), pikeperch ( Stizostedion lucioperca ) and European catfish ( Silurus glanis ): a bioenergetics approach  

Microsoft Academic Search

Bioenergetics models were applied for the assessment of food consumption of northern pike, pikeperch and European catfish\\u000a in drainable ponds of 0.4 ha. The ponds were stocked with known numbers of the 0+ predators. The prey fish consisted of naturally recruited 0+ cyprinids (rudd, roach and bream). The study shows that the impact of the three 0+ piscivores on the

Alexander J. P. Raat

1990-01-01

42

Stocking impact and temporal stability of genetic composition in a brackish northern pike population (Esox lucius L.), assessed using microsatellite DNA analysis of historical and contemporary samples  

Microsoft Academic Search

During the last decade, brackish northern pike populations in Denmark have been subject to stocking programmes, using nonindigenous pike from freshwater lakes, in order to compensate for drastic population declines. The present study was designed to investigate the genetic impact of stocking freshwater pike into a brackish pike population in Stege Nor, Denmark. We analysed polymorphism at eight microsatellite loci

P F Larsen; M M Hansen; E E Nielsen; L F Jensen; V Loeschcke

2005-01-01

43

A survey of the spawning of perch (Perca fluviatilis), pike (Esox lucius), and roach (Rutilus rutilus), using artificial spawning substrates in lakes  

Microsoft Academic Search

The development of spawning in perch, pike and roach in Lake Geneva has been studied by means of artificial spawning substrates, laid at different depths, from 1984 to 1993. In Lake Geneva, perch spawned in May. A rise of surface water temperature up to 14 °C stimulated spawning activity while bad weather (surface temperature at 10 °C) induced a spread

C. Gillet; J. P. Dubois

1995-01-01

44

Biomagnification of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) studied in pike ( Esox lucius), perch ( Perca fluviatilis) and roach ( Rutilus rutilus) from the Baltic Sea  

Microsoft Academic Search

Pike, perch and roach from rural waters of the Baltic Sea were investigated for possible biomagnification of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). For this we used data on ?15N, weight and sex of the fish. We were able to separate body size effects from trophic position effects on biomagnification. Both these parameters lead to biomagnification of PCBs

Sven Burreau; Yngve Zebühr; Dag Broman; Rasha Ishaq

2004-01-01

45

Metabolic rate and cost of growth in juvenile pike ( Esox lucius L.) and perch ( Perca fluviatilis L.): the use of energy budgets as indicators of environmental change  

Microsoft Academic Search

Summary  Energy budgets of juvenile pike and perch (weighing approximately 3 g) were determined in experiments lasting up to 4 days,\\u000a by simultaneously measuring oxygen consumption, food consumption, and growth of individual fish. Although the basic pattern\\u000a of energy allocation was identical in the two species, perch subjected to constant light (PEL) showed faster growth, higher\\u000a assimilation and conversion efficiency, and

W. Wieser; N. Medgyesy

1991-01-01

46

Arrays of Lucius microprisms for directional allocation of light and autostereoscopic three-dimensional displays.  

PubMed

Directional and asymmetric properties are attractive features in nature that have proven useful for directional wetting, directional flow of liquids and artificial dry adhesion. Here we demonstrate that an optically asymmetric structure can be exploited to guide light with directionality. The Lucius prism array presented here has two distinct properties: the directional transmission of light and the disproportionation of light intensity. These allow the illumination of objects only in desired directions. Set up as an array, the Lucius prism can function as an autostereoscopic three-dimensional display. PMID:21878909

Yoon, Hyunsik; Oh, Sang-Guen; Kang, Dae Shik; Park, Jong Myoung; Choi, Se Jin; Suh, Kahp Y; Char, Kookheon; Lee, Hong H

2011-08-30

47

Tanks at Checkpoint Charlie: Lucius Clay and the Berlin Crisis, 1961–62  

Microsoft Academic Search

The stand-off of Soviet and American tanks in the heart of Berlin in October 1961 constituted the most dangerous moment of the Cold War in Europe. It has been attributed to unnecessarily confrontational policies of General Lucius D. Clay, who served as President Kennedy's Special Representative in Berlin. This article assesses how the crisis evolved from the Berlin Wall to

Ingo Wolfgang Trauschweizer

2006-01-01

48

Foraging and Flocking Behavior  

NSDL National Science Digital Library

In this laboratory exercise, the following issues are examined: 1) why neither predators nor prey go extinct when there is a long period of nonrenewal of the prey population 2) the effects of habitat on foraging speed 3) the advantages foragers can gain from experience in foraging 4) the advantage of exclusive use of an area for foragers 5) the effects of food density on foraging speed 6) the advantages of camouflage for prey 7) the effect of experience in forming search images for one out of several types of prey and 8) the advantages of foraging in mixed species flocks for avoiding predation.

Smith, Christopher

2010-02-16

49

Neural Mechanisms of Foraging  

PubMed Central

Behavioural economic studies, involving limited numbers of choices, have provided key insights into neural decision-making mechanisms. By contrast, animals’ foraging choices arise in the context of sequences of encounters with prey/food. On each encounter the animal chooses to engage or whether the environment is sufficiently rich that searching elsewhere is merited. The cost of foraging is also critical. We demonstrate humans can alternate between two modes of choice, comparative decision-making and foraging, dependent on distinct neural mechanisms in ventromedial prefrontal (vmPFC) and anterior cingulate cortex (ACC) employing distinct reference frames; in ACC choice variables are represented in invariant reference to foraging/searching for alternatives. While vmPFC encodes values of specific well-defined options, ACC encodes the average value of the foraging environment and cost of foraging.

Kolling, Nils; Behrens, Timothy EJ; Mars, Rogier B; Rushworth, Matthew FS

2012-01-01

50

Foraging Experiences with Children  

ERIC Educational Resources Information Center

|Provided are foraging experiences and wild foods information for utilization in the urban school curriculum. Food uses are detailed for roses, dandelions, wild onions, acorns, cattails, violets and mints. (BT)|

Russell, Helen Ross

1976-01-01

51

FORAGE PRODUCTION AND SPECIES DIVERSITY IN PASTURES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mixtures of forage species with differential ability to exploit resources could benefit from highly variable environments. Consequently, complex forage mixtures may improve sustainability of forage production under rotational grazing. This study was undertaken to determine whether forage production ...

52

Optimal Foraging in Semantic Memory  

ERIC Educational Resources Information Center

|Do humans search in memory using dynamic local-to-global search strategies similar to those that animals use to forage between patches in space? If so, do their dynamic memory search policies correspond to optimal foraging strategies seen for spatial foraging? Results from a number of fields suggest these possibilities, including the shared…

Hills, Thomas T.; Jones, Michael N.; Todd, Peter M.

2012-01-01

53

Intrinsically motivated information foraging  

Microsoft Academic Search

We treat information gathering as a POMDP in which the goal is to maximize an accumulated intrinsic reward at each time step based on the negative entropy of the agent's beliefs about the world state. We show that such information foraging agents can discover intelligent exploration policies that take into account the long-term effects of sensor and motor actions, and

Ian Fasel; Andrew Wilt; Nassim Mafi; Clayton T. Morrison

2010-01-01

54

Optimal Foraging by Zooplankton  

NASA Astrophysics Data System (ADS)

We describe experiments with several species of the zooplankton, Daphnia, while foraging for food. They move in sequences: hop-pause-turn-hop etc. While we have recorded hop lengths, hop times, pause times and turning angles, our focus is on histograms representing the distributions of the turning angles. We find that different species, including adults and juveniles, move with similar turning angle distributions described by exponential functions. Random walk simulations and a theory based on active Brownian particles indicate a maximum in food gathering efficiency at an optimal width of the turning angle distribution. Foraging takes place within a fixed size food patch during a fixed time. We hypothesize that the exponential distributions were selected for survival over evolutionary time scales.

Garcia, Ricardo; Moss, Frank

2007-03-01

55

Wide home ranges for widely foraging lizards  

Microsoft Academic Search

Space usage by animals may be influenced by a range of factors. In this study we investigate whether foraging behaviour affects the home range size of lizards. Two distinct tactics of foraging have been recognized in predators: sit-and-wait foraging (SW) and active foraging (AF). Foraging activity level of a data set of lizard species, mainly compiled from literature, is compared

Dave Verwaijen; Raoul Van Damme

2008-01-01

56

Individual foraging in the ant Pachycondyla apicalis  

Microsoft Academic Search

A model of individual foraging in social insects as presented that formalises the dynamics of foraging and concentrates on the collective rather than the individual benefit, quantifying the relationships between a colony's foraging area, number of foragers and foraging energy budget and the food sources' rate of arrival, disappearance and capture. A series of experiments, in which a number of

S. Goss; D. Fresneau; J. L. Deneubourg; J.-P. Lachaud; J. Valenzuela-Gonzalez

1989-01-01

57

The Dynamics of Foraging Ants  

NASA Astrophysics Data System (ADS)

We experimentally study the foraging of small black ants, Formicinae lasius flavus, in order to describe their foraging behavior mathematically. Individual ants are allowed to forage on a two-dimensional surface in the absence of any food sources. The position of the ant as a function of time is determined using a high-resolution digital camera. Analysis of the average square displacements of many ants suggests that the foraging strategy is a non-reversing random walk. Moreover, the ants do not retrace their steps to return home but instead continue the random walk until it brings them back near their starting point.

Baxter, G. William

2009-03-01

58

WHY DO FORAGERS SHARE AND SHARERS FORAGE? EXPLORATIONS OF SOCIAL DIMENSIONS OF FORAGING  

Microsoft Academic Search

Commonly studied hunter-gatherer traits, such as grouping and sharing, may require special attention when self-selection introduces bias into typical analyses. We therefore re-examine forager sociality by asking a series of nested questions: (1)To what extent are foraging groups random samples from the larger population? (2)What social and economic factors might explain the composition of foraging groups? (3)If certain groups of

Michael Gurven; Kim Hill; Felipe Jakugi

59

Pasture forages for small ruminants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Small ruminant producers in Appalachia have many questions about forage management. Forage management decisions need to be keyed to the specific needs of the small ruminant t species to be grazed. Sheep and goats are different from each other and both are very different from cattle. Important con...

60

NONSTRUCTURAL CARBOHYDRATES IN OAT FORAGE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nonstructural carbohydrates (NSC) fractions found in forage may play a role in equine diseases that involve carbohydrate intolerance, such as laminitis. Sugars in forage may adversely affect equines with dysfunctions of glucose metabolism. Insulin resistance has been associated with laminitis in e...

61

Rainfall Effects on Wilting Forages  

Technology Transfer Automated Retrieval System (TEKTRAN)

Given the uncertainty of the weather and inherent differences between forage crops, specific recommendations for managing potential rain damage to wilting forages are difficult. However, there are a number of principles that can be applied to best manage the potential for rain damage. These science-...

62

RED-COCKADED WOODPECKER FORAGING BEHAVIOR  

Microsoft Academic Search

We studied Red-cockaded Woodpeckers (Picoides borealis) to examine the effect of status and gender on foraging behavior. Foraging behavior of breeding pairs extended beyond separation by foraging height to include zones (bole, trunk in crown, primary limb, secondary limb) of the tree used and foraging methods (scaling, probing, excavating). Helper males and juvenile females maintained partial spatial separation from breeding

D. CRAIG RUDOLPH; RICHARD N. CONNER; RICHARD R. SCHAEFER; NANCY E. KOERTH

2007-01-01

63

Gyrodactylus neili n. sp. (Monogenea: Gyrodactylidae), a parasite of chain pickerel Esox niger Lesueur (Esocidae) from freshwaters of New Brunswick, Canada  

Microsoft Academic Search

Gyrodactylus neili n. sp. (Monogenea: Gyrodactylidae) is described from the fins and body surface of Esox niger Lesueur (chain pickerel) (Esocidae) from the St. Croix River drainage, New Brunswick, Canada. G.?neili n. sp. resembles most closely G. fryi Cone & Dechtiar, 1984, a parasite of E. masquinongy in North America, in having relatively large thin hamuli, well-developed marginal hook sickles

Jaclyn LeBlanc; Haakon Hansen; Michael Burt; David Cone

2006-01-01

64

7 CFR 1437.401 - Forage.  

Code of Federal Regulations, 2013 CFR

...as to be suitable for grazing livestock or mechanical harvest...claims on forage for grazing benefits will be determined...intended as forage for livestock consumption as either...prior to the onset of grazing of any intended...

2013-01-01

65

NUTRIENT CYCLING IN FORAGE PRODUCTION SYSTEMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nutrient cycling in forage production systems is complicated and crucial; complicated, because elements can exist in many forms and are affected by both biological and physical processes, and crucial, because nutrients affect productivity, profitability, and environmental sustainability of forage sy...

66

Integrated forage crop refinery system  

SciTech Connect

The proposed program involves the development of an integrated agricultural-chemical refining system for converting forage crops to useful foods, feeds, fuels, and chemicals. TVA has facilities and resources available to support extensive research and development activities. Modification can easily be made in the existing experimental facility being used to develop acid hydrolysis of corn stover, to include production of products other than fuel ethanol from forages. These products include protein, lignin-derived products, chemicals, single-cell protein, methane, aquaculture feed, and distillers solids. Refining forage crops in this manner has potential to increase the value of that crop and produce an economical integrated system. The results of the program will also be directly applicable to other areas and regions of the US. 11 refs., 7 figs., 9 tabs.

Barrier, J.W.; Broder, J.D.; Madewell, C.E.; Mays, D.A.

1985-04-01

67

Predicting Forage Indigestible NDF from Lignin Concentration  

Microsoft Academic Search

We used chemical composition and in vitro digestibility data from temperate and tropical forages to develop relationships between indices of lignification and forage indigestible NDF. Neutral detergent fiber indigestibility increased nonlinearly as the lignin concentration of the NDF increased. Differ- ences in estimated indigestible NDF using equations developed for a specific forage class (C3 and C4 grasses and legumes) were

M. J. Traxler; D. G. Fox; P. J. Van Soest; A. N. Pell; C. E. Lascano; D. P. D. Lanna; J. E. Moore; R. P. Lana; M. Velez; A. Flores

2009-01-01

68

Allometric scaling of ant foraging trail networks  

Microsoft Academic Search

The aggregation of individuals into colonies raises important questions about scaling of structure and function. We model the metabolic benefits and costs of two-dimensional, fractal- like foraging trails, such as those used by ant colonies. Total area foraged by the colony and, consequently, resource flow to the nest and rate of colony metabolism, increase non-linearly with number of foragers (F)

Joseph Jun; John W. Pepper; Van M. Savage; James F. Gillooly; James H. Brown

2003-01-01

69

FORAGES FOR CONSERVATION AND IMPROVED SOIL QUALITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Forages are often the most cost-effective tools for reducing soil erosion and for conserving or stabilizing soil resources. This chapter reviews the various roles that forages can have in promoting conservation and maintaining or improving soil quality. Well-managed forages can protect and improve s...

70

Analysis of Forages by Infrared Reflectance1  

Microsoft Academic Search

Infrared reflectance is a rapid accurate procedure for measuring nutrients in grains and forages. Factors that affect prediction of forage quality include plant species, method of preservation, and constituents in the forage other than those being measured. Selection of wavelengths for prediction is the key. Statistical procedures are being studied to improve selection of wavelength and to lower prediction errors.

J. S. Shenk; M. O. Westerhaus; M. R. Hoover

1979-01-01

71

Breeding for increased forage quality  

Technology Transfer Automated Retrieval System (TEKTRAN)

Forage crops have a large number of benefits to society, including ecosystem services such as soil and water conservation, wildlife habitat, and diversification of the agricultural landscape. However, their principal function can only be realized when they are processed through livestock to produce ...

72

Foraging currencies, metabolism and behavioural routines.  

PubMed

A fundamental issue in foraging theory is whether it is possible to find a simple currency that characterizes foraging behaviour. If such a currency exists, then it is tempting to argue that the selective forces that have shaped the evolution of foraging behaviour have been understood. We review previous work on currencies for the foraging behaviour of an animal that maximizes total energy gained. In many circumstances, it is optimal to maximize a suitably modified form of efficiency. We show how energy gain, predation and damage can be combined in a single currency based on reproductive value. We draw attention to the idea that hard work may have an adverse effect on an animal's condition. We develop a model of optimal foraging over a day when a forager's state consists of its energy reserves and its condition. Optimal foraging behaviour in our model depends on energy reserves, condition and time of day. The pattern of optimal behaviour depends strongly on assumptions about the probability that the forager is killed by a predator. If condition is important, no simple currency characterizes foraging behaviour, but behaviour can be understood in terms of the maximization of reproductive value. It may be optimal to adopt a foraging option that results in a rate of energy expenditure that is less than the rate associated with maximizing efficiency. PMID:23730810

Houston, Alasdair I; McNamara, John M

2013-06-01

73

Hazardous duty pay and the foraging cost of predation  

Microsoft Academic Search

We review the concepts and research associated with measuring fear and its consequences for foraging. When foraging, animals should and do demand hazardous duty pay. They assess a foraging cost of predation to compensate for the risk of predation or the risk of catastrophic injury. Similarly, in weighing foraging options, animals tradeoff food and safety. The foraging cost of predation

Joel S. Brown; Burt P. Kotler

2004-01-01

74

Geographic profiling and animal foraging.  

PubMed

Geographic profiling was originally developed as a statistical tool for use in criminal cases, particularly those involving serial killers and rapists. It is designed to help police forces prioritize lists of suspects by using the location of crime scenes to identify the areas in which the criminal is most likely to live. Two important concepts are the buffer zone (criminals are less likely to commit crimes in the immediate vicinity of their home) and distance decay (criminals commit fewer crimes as the distance from their home increases). In this study, we show how the techniques of geographic profiling may be applied to animal data, using as an example foraging patterns in two sympatric colonies of pipistrelle bats, Pipistrellus pipistrellus and P. pygmaeus, in the northeast of Scotland. We show that if model variables are fitted to known roost locations, these variables may be used as numerical descriptors of foraging patterns. We go on to show that these variables can be used to differentiate patterns of foraging in these two species. PMID:16263134

Le Comber, Steven C; Nicholls, Barry; Rossmo, D Kim; Racey, Paul A

2005-11-02

75

Patterns of energy acquisition by a central place forager: benefits of alternating short and long foraging trips  

Microsoft Academic Search

In some seabirds, foraging trips have been defined as either long or short, with the length of time spent traveling to the foraging area apparently a critical feature in determining foraging trip length. Using logger technology, together with complimentary data from published studies, we investigated traveling and foraging times in 18 free-living Adélie Penguins Pygoscelis adeliae, which were foraging for

Yan Ropert-Coudert; Rory P. Wilson; Francis Daunt; Akiko Katoa

2004-01-01

76

Bacteria Foraging Based Agent Feature Selection Algorithm  

Microsoft Academic Search

\\u000a This paper provides an agent genetic algorithm based on bacteria foraging strategy (BFOA-L) as the feature selection method,\\u000a and presents the combined method of link-like agent structure and neural network based on bacteria foraging algorithm (BFOA).\\u000a It introduces the bacteria foraging (BF) action into the feature selection and utilizes the neural network structure achieve\\u000a fuzzy logic inference, so that the

Dongying Liang; Weikun Zheng; Yueping Li

2011-01-01

77

Sex differences in Adélie penguin foraging strategies  

Microsoft Academic Search

Consistent sex differences in foraging trip duration, feeding locality and diet of breeding Adlie penguins (Pygoscelis adeliae) were demonstrated at two widely separated locations over several breeding seasons. Differences in foraging behaviour were\\u000a most pronounced during the guard stage of chick rearing. Female penguins made on average longer foraging trips than males,\\u000a ranged greater distances more frequently and consumed larger

Judy Clarke; Bryan Manly; Knowles Kerry; Heather Gardner; Enrica Franchi; Simonetta Corsolini; Silvano Focardi

1998-01-01

78

Foraging guilds of North American birds  

Microsoft Academic Search

We propose a foraging guild classification for North American inland, coastal, and pelagic birds. This classification uses a three-part identification for each guild—major food, feeding substrate, and foraging technique—to classify 672 species of birds in both the breeding and nonbreeding seasons. We have attempted to group species that use similar resources in similar ways. Researchers have identified foraging guilds generally

Richard M. De Graaf; Nancy G. Tilghman; Stanley H. Anderson

1985-01-01

79

Foraging guilds of North American birds  

Microsoft Academic Search

We propose a foraging guild classification for North American inland, coastal, and pelagic birds. This classification uses a three-part identification for each guild---major food, feeding substrate, and foraging technique---to classify 672 species of birds in both the breeding and nonbreeding seasons. We have attempted to group species that use similar resources in similar ways. Researchers have identified foraging guilds generally

Richard M. de Graaf; Nancy G. Tilghman; Stanley H. Anderson

1985-01-01

80

Living Mulch Forage Yield and Botanical Composition in a Corn-Soybean-Forage Rotation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Managing forages as living mulches during row crop production requires suppressing the forages to produce economical crop yields. The objective of this research was to identify forage plants with varied growth habit, persistence, and yield potential to provide desirable ecosystem functions and high ...

81

Genetic determination of nectar foraging, pollen foraging, and nest-site scouting in honey bee colonies  

Microsoft Academic Search

Allozyme analyses of honey bee workers revealed significant differences in the intracolonial subfamily composition of groups of nectar foragers, pollen foragers, and nest-site scouts. These differences demonstrate that colony genetic structure influences the division of labor among older foraging-age bees just as it does for younger workers. The maintenance of genetic variability for the behavior of individual workers and its

Gene E. Robinson; Robert E. Page

1989-01-01

82

7 CFR 457.117 - Forage production crop insurance provisions.  

Code of Federal Regulations, 2010 CFR

...producers. Fall planted. A forage crop seeded after June 30. Forage âPlanted perennial alfalfa...perennial red clover, perennial grasses, or a mixture thereof, or... Harvest âRemoval of forage from the windrow or...

2010-01-01

83

7 CFR 457.151 - Forage seeding crop insurance provisions.  

Code of Federal Regulations, 2010 CFR

...acreage. Fall planted âA forage crop seeded after June 30. Forage âPlanted perennial alfalfa...perennial red clover, perennial grasses, or a mixture thereof, or...Harvest. Severance of the forage plant from its roots....

2010-01-01

84

7 CFR 457.117 - Forage production crop insurance provisions.  

Code of Federal Regulations, 2010 CFR

...producers. Fall planted. A forage crop seeded after June 30. Forage âPlanted perennial alfalfa...perennial red clover, perennial grasses, or a mixture thereof, or... Harvest âRemoval of forage from the windrow or...

2009-01-01

85

7 CFR 457.151 - Forage seeding crop insurance provisions.  

Code of Federal Regulations, 2010 CFR

...acreage. Fall planted âA forage crop seeded after June 30. Forage âPlanted perennial alfalfa...perennial red clover, perennial grasses, or a mixture thereof, or...Harvest. Severance of the forage plant from its roots....

2009-01-01

86

Selective Predation by Three Esocids: The Role of Prey Behavior and Morphology  

Microsoft Academic Search

We documented differential vulnerability of fathead minnows Pimephales promelas, gizzard shad Dorosoma cepedianum. and bluegills Lepomis macrochirus to predation by muskel- lunge Esox masquinongy. northern pike E. lucius. and tiger muskellunge £\\

DAVID H. WAHL; ROY A. STEIN

1988-01-01

87

Factors Related to Fish Growth in Northwestern Wisconsin Lakes.  

National Technical Information Service (NTIS)

Average fish growth was compared with physical, limnological, and fish abundance data from 115 northwestern Wisconsin lakes. The target species was bluegill (Lepomis macrochirus), but data were also collected on northern pike (Esox lucius), rock bass (Amb...

H. E. Snow M. D. Staggs

1994-01-01

88

Northern Pike Removal Smallmouth Bass Monitoring and Native Fish Monitoring in the Yampa River, Hayden to Craig Reach, 2004-2006.  

National Technical Information Service (NTIS)

Northern pike (Esox lucius) is a large aggressive, esocid native to many North American drainages that has been widely stocked outside of its natural range. Smallmouth bass (Micropterus dolomieu) is an exotic predatory fish present in the Yampa River. The...

G. B. Haines S. T. Finney

2008-01-01

89

Polyphenol oxidase activity in annual forage clovers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Polyphenol oxidase (PPO)-mediated phenol reactions in red clover (Trifolium pratense L.) bind forage protein and reduce proteolysis, producing beneficial effects on forage protein degradability, silage fermentation, and soil-N cycling. We evaluated PPO activity in seven previously untested annual c...

90

NON-TRADITIONAL FORAGES FOR CENTRAL APPALACHIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Small ruminant forage research at AFSRC is designed to improve forage and pasture management for small ruminants, especially as related to control of gastrointestinal nematode (GIN) parasites. Alfalfa pasture produced better meat goat weight gains than orchardgrass, but red clover pasture was diff...

91

Forager Food Sharing Economy: Transfers and Exchangesi)  

Microsoft Academic Search

African forests, and the Kalahari. Although foraging societies did not have a large number of people, foraging society and culture was and is of interest for several reasons. Here was a social and cultural form that was interesting in its own right. The apparent simpligity was an effective counter foil to a view of humans that assumed the existence of

RoBERT C. HuNT; Brandeis Univensity

92

Optimal foraging: A case for random movement  

Microsoft Academic Search

The bumblebee, Bombus flavifrons, forages randomly with respect to direction on Polemonium foliosissimum. This foraging pattern is as predicted for a system where there is a low probability of revisiting any given flower upon returning to a patch. This low revisitation probability is a function of the floral resource arrangement. It is further shown that B. flavifrons is using the

Michael Zimmerman

1979-01-01

93

DEVELOPING BETTER FORAGES FOR THE SOUTH 1  

Microsoft Academic Search

Forages for the South must be adapted to the soil and the climate. The acidic, infertile soils can, and usually must, be improved by adding lime and fertilizer. The rainfall (1,100+ mm\\/yr) and the temperature generally favor the growth of many forage species. But the occasional droughts and freezes well below 0 C limit the number that can be considered

Glenn W. Burton

2010-01-01

94

Forage Species for Rubber Plantations in Indonesia  

Microsoft Academic Search

Solar radiation measurements under rubber trees showed a rapid decline in light transmission to less than two per cent of the full sunlight values from planting to 8-year-old trees. Yield of forages decreases sharply under increasing shade, with local species showing less decline than the improved tropical forages. Asystasia intrusa gave a higher yield under shade than other local and

M. D. Sanchez; T. H. Ibrahim

95

Prey Processing in Central Place Foragers  

Microsoft Academic Search

The importance of prey processing as an integral part of foraging behaviour has long been acknowledged, but little theoretical consideration has been given to the optimization of the processing behaviour itself. Processing renders food down to ingestible, palatable portions, and also removes non-essential mass thus reducing transport costs. Here, several models of processing are developed for a central place forager.

SEAN A. RANDS; ALASDAIR I. HOUSTON; CATHERINE E. GASSON

2000-01-01

96

BENEFITS OF MEASURING AND BUDGETING PASTURE FORAGE  

Technology Transfer Automated Retrieval System (TEKTRAN)

We modeled two farms that differed in size, grazing management, and feeding strategy to determine the economic value of accurate forage measurement on pasture. We first modeled the optimal management and performance conditions for each farm with the assumption that forage on pasture was measured acc...

97

Palatability of Forage Chicory Cultivars for Goats  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sesquiterpene lactones (SL) in forage chicory (Cichorium intybus L.) may have anthelmintic activity against gastrointestinal parasites in sheep and goats, but have been implicated in poor palatability of forage. We used three levels of soil P fertilization to influence SL concentrations in three cu...

98

Behavioral Contrast in a Group Foraging Paradigm  

Microsoft Academic Search

Two experiments examined multiple schedule behavioral contrast in a group foraging paradigm. Groups of five rats foraged simultaneously in a large open field apparatus with two feeding stations. Food pellets were delivered at each of the feeding stations on multiple Variable Time schedules. As predicted by both the matching law and the ideal free distribution, the relative distribution of behavior

James Dougan; Valeri Farmer-Dougan

2005-01-01

99

Bacteria foraging in turbulent waters  

NASA Astrophysics Data System (ADS)

Marine bacteria are the Ocean's recyclers, contributing to as much as 50% of the productivity of the marine food web. Bacteria forage on patches of dissolved nutrients using chemotaxis, the ability to swim up chemical gradients. As turbulence is ubiquitous in the Ocean, it is important to understand how turbulent flow conditions affect bacterial foraging. We used three-dimensional, isotropic direct numerical simulations coupled with a bacterial transport equation to address this problem. After the flow is continuously forced until it reaches a steady state, microscale nutrient patches are injected into the turbulent flow, and stirring produces thin nutrient filaments. Two populations of bacteria compete against each other: one population is motile and chemotactic (`active'), the other is non-motile (`passive'). The distribution of both populations is initially uniform. Chemotaxis allows active bacteria to cluster near the center of the nutrient filaments, increasing their nutrient uptake relative to passive bacteria. Increasing the turbulence intensity increases the short-term chemotactic advantage by quickly producing large gradients in the nutrient concentration, but also leads to rapid mixing of the nutrient field, which makes the chemotactic advantage short-lived. The results suggest that the evolutionary advantage of chemotaxis, based on the increase in nutrient uptake relative to the energetic cost of swimming, strongly depends on the turbulence level.

Taylor, John; Tang, Wenbo; Stocker, Roman

2009-11-01

100

Bioaccumulation of Heavy Metals in Freshwater Fish Species, Anzali, Iran  

Microsoft Academic Search

The main objectives of study were to monitor the metals concentrations, in freshwater fish species, Carassius gibelio and Esox lucius; and to identify any relationships between species and bioaccumulation of metals. The highest concentration of metals (cadmium,\\u000a 1.96; copper, 24.2; zinc, 49.6; lead, 5.4; chromium, 4.4) between the fish species and tissues was in the liver of Esox lucius, while

Mohammad Ebrahimpour; Alireza Pourkhabbaz; Rahimeh Baramaki; Hadi Babaei; Mohammadreza Rezaei

101

Perennial Forages as Second Generation Bioenergy Crops  

PubMed Central

The lignocellulose in forage crops represents a second generation of biomass feedstock for conversion into energy-related end products. Some of the most extensively studied species for cellulosic feedstock production include forages such as switchgrass (Panicum virgatum L.), reed canarygrass (Phalaris arundinacea L.), and alfalfa (Medicago sativa L.). An advantage of using forages as bioenergy crops is that farmers are familiar with their management and already have the capacity to grow, harvest, store, and transport them. Forage crops offer additional flexibility in management because they can be used for biomass or forage and the land can be returned to other uses or put into crop rotation. Estimates indicate about 22.3 million ha of cropland, idle cropland, and cropland pasture will be needed for biomass production in 2030. Converting these lands to large scale cellulosic energy farming could push the traditional forage-livestock industry to ever more marginal lands. Furthermore, encouraging bioenergy production from marginal lands could directly compete with forage-livestock production.

Sanderson, Matt A.; Adler, Paul R.

2008-01-01

102

Flexible search tactics and efficient foraging in saltatory searching animals  

Microsoft Academic Search

Foraging is one of the most important endeavors undertaken by animals, and it has been studied intensively from both mechanistic-empirical and optimal foraging perspectives. Planktivorous fish make excellent study organisms for foraging studies because they feed frequently and in a relatively simple environment. Most optimal foraging studies of planktivorous fish have focused, either on diet choice or habitat selection and

W. John O'Brien; Barbara I. Evans; Howard I. Browman

1989-01-01

103

Dynamics of mule deer forage in the Sonoran Desert  

Microsoft Academic Search

Forage availability for mule deer (Odocoileus hemionus) in the Sonoran Desert depends on plant biomass, which is influenced by rainfall. We determined how rainfall, temperature and plant characteristics affected biomass of deer forage. We measured forage biomass, rainfall and temperature every 3 months from April 2000 to December 2002. Quarterly rainfall ranged from <1 to 57mm, and forage biomass in

J. P. Marshal; P. R. Krausman; V. C. Bleich

2005-01-01

104

Thermal constraints on foraging in adult european starlings  

Microsoft Academic Search

The operative temperature of the environment was estimated for starlings using hollow, unheated taxidermic mounts. On average, adults foraging in full sun were characterized by shorter foraging bouts than those adults foraging in full shade. Simultaneous observations of air temperature, operative temperature, and the foraging duration of adults indicated that air temperature was a poor predictor of the maximum length

L. Clark

1987-01-01

105

Information Foraging in Nuclear Power Plant Control Rooms  

Microsoft Academic Search

nformation foraging theory articulates the role of the human as an 'informavore' that seeks information and follows optimal foraging strategies (i.e., the 'information scent') to find meaningful information. This paper briefly reviews the findings from information foraging theory outside the nuclear domain and then discusses the types of information foraging strategies operators employ for normal and off-normal operations in the

R. L. Boring

2011-01-01

106

Differential effects of structural complexity on predator foraging behavior  

Microsoft Academic Search

The choice of predator foraging mode has important consequences for ecological communities. Foraging mode designations are often made on the basis of predator activity, yet activity can be affected by various environmental stimuli independent of changes in foraging mode. Structural complexity can reduce predator activity by either interfering with predator vision and mobility or as part of a foraging mode

Matt J. Michel; Melinda M. Adams

2009-01-01

107

Biomimicry of bacterial foraging for distributed optimization and control  

Microsoft Academic Search

We explain the biology and physics underlying the chemotactic (foraging) behavior of E. coli bacteria. We explain a variety of bacterial swarming and social foraging behaviors and discuss the control system on the E. coli that dictates how foraging should proceed. Next, a computer program that emulates the distributed optimization process represented by the activity of social bacterial foraging is

K. M. Passino

2002-01-01

108

Paying for information: partial loads in central place foragers  

Microsoft Academic Search

Information about food sources can be crucial to the success of a foraging animal. We predict that this will influence foraging decisions by group-living foragers, which may sacrifice short-term foraging efficiency to collect information more frequently. This result emerges from a model of a central-place forager that can potentially receive information on newly available superior food sources at the central

A. Dornhaus; E. J. Collins; F.-X. Dechaume-Moncharmont; A. I. Houston; N. R. Franks; J. M. McNamara

2006-01-01

109

Individual foraging in the antPachycondyla apicalis.  

PubMed

A model of individual foraging in social insects as presented that formalises the dynamics of foraging and concentrates on the collective rather than the individual benefit, quantifying the relationships between a colony's foraging area, number of foragers and foraging energy budget and the food sources' rate of arrival, disappearance and capture. A series of experiments, in which a number of prey were offered to colonies of the individually foraging antPachycondyla (ex-Neoponera) apicalis confirm the hypotheses implicit in the model and measured the rates of capture and competition. 60 days observation of 3P. apicalis colonies' foraging activity are summarised and used in conjunction with the model to obtain estimations of the density and rate of arrival of available prey in the foraging area. We examine how a colony's foraging benefit may be influenced by its foraging area, the number of foragers, and the forager/non-forager ratio and show that a colony's jocial structure strongly limits its potential foraging benefit. Within these limits,P. apicalis does not appear to be an optimal forager. PMID:23494347

Goss, S; Fresneau, D; Deneubourg, J L; Lachaud, J P; Valenzuela-Gonzalez, J

2013-03-13

110

Food Consumption and Growth of Three Esocids: Field Tests of a Bioenergetic Model  

Microsoft Academic Search

We quantified diet and compared field estimates of growth and daily ration with predictions from a bioenergetic model for young-of-year muskellunge Esox masquinongy, northern pike E. lucius, and tiger muskellunge E. masquinongy × E. lucius introduced into five Ohio reservoirs. Gizzard shad Dorosoma cepedianum dominated esocid diets (77–97% by weight) through autumn but were absent by spring. Diets in late

David H. Wahl; Roy A. Stein

1991-01-01

111

Shade Tolerance of Tropical Forages: A Review  

Microsoft Academic Search

The paper reviews the shade tolerance of tropical forages and discusses the adaptation of species to low light. Shading reduces tiller production and leaf, stem, stubble and root yield but increases specific leaf area and shoot\\/root and leaf\\/stem ratios, particularly in shade-tolerant species. Yield responses of many tropical forages to shading reflected the strong relationship between productivity and irradiance, but

C. C. Wong

112

Tillage and forage system effects on forage yields and nutrient uptake under broiler litter amended soils.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Planting and harvesting high yielding forage grasses may remove phosphorus (P), copper (Cu) and zinc (Zn) from surface soils with a long history of broiler litter application. A study was conducted in Alabama’s Sand Mountain region from 1998 to 2000 to determine tillage and forage systems best suite...

113

Foraging ecology of the Tokay gecko, Gekko gecko in a residential area in Thailand  

Microsoft Academic Search

The foraging behavior of Gekko gecko was observed at the visitor complex of the Khao Khiao Open Zoo at the Khao Khiao-Khao Chomphu Wildlife Sanctuary in Chon Buri Province, Thailand. Foraging parameters of G. gecko (foraging period, time spent moving, foraging attempts, foraging success, prey size consumed, and foraging distance) did not vary significantly between males, females, and juveniles. Individuals

Anchalee Aowphol; Kumthorn Thirakhupt; Jarujin Nabhitabhata; Harold K. Voris

2006-01-01

114

A DIGITAL PHOTOGRAPHIC TECHNIQUE FOR ASSESSING FORAGE UTILIZATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Changes in forage utilization have been difficult to measure nondestructively without some level of subjectivity. This subjectivity, combined with a lack of reproducibility of visual estimates, has made forage utilization measurement techniques a topic of considerable discussion. The objective of ...

115

Metabolomics of forage plants: a review  

PubMed Central

Background Forage plant breeding is under increasing pressure to deliver new cultivars with improved yield, quality and persistence to the pastoral industry. New innovations in DNA sequencing technologies mean that quantitative trait loci analysis and marker-assisted selection approaches are becoming faster and cheaper, and are increasingly used in the breeding process with the aim to speed it up and improve its precision. High-throughput phenotyping is currently a major bottle neck and emerging technologies such as metabolomics are being developed to bridge the gap between genotype and phenotype; metabolomics studies on forages are reviewed in this article. Scope Major challenges for pasture production arise from the reduced availability of resources, mainly water, nitrogen and phosphorus, and metabolomics studies on metabolic responses to these abiotic stresses in Lolium perenne and Lotus species will be discussed here. Many forage plants can be associated with symbiotic microorganisms such as legumes with nitrogen fixing rhizobia, grasses and legumes with phosphorus-solubilizing arbuscular mycorrhizal fungi, and cool temperate grasses with fungal anti-herbivorous alkaloid-producing Neotyphodium endophytes and metabolomics studies have shown that these associations can significantly affect the metabolic composition of forage plants. The combination of genetics and metabolomics, also known as genetical metabolomics can be a powerful tool to identify genetic regions related to specific metabolites or metabolic profiles, but this approach has not been widely adopted for forages yet, and we argue here that more studies are needed to improve our chances of success in forage breeding. Conclusions Metabolomics combined with other ‘-omics’ technologies and genome sequencing can be invaluable tools for large-scale geno- and phenotyping of breeding populations, although the implementation of these approaches in forage breeding programmes still lags behind. The majority of studies using metabolomics approaches have been performed with model species or cereals and findings from these studies are not easily translated to forage species. To be most effective these approaches should be accompanied by whole-plant physiology and proof of concept (modelling) studies. Wider considerations of possible consequences of novel traits on the fitness of new cultivars and symbiotic associations need also to be taken into account.

Rasmussen, Susanne; Parsons, Anthony J.; Jones, Christopher S.

2012-01-01

116

Foraging behaviour of Armillaria rhizomorph systems.  

PubMed

The foraging behaviour of Armillaria rhizomorph systems is poorly understood owing to their cryptic position within the soil. We investigated foraging in a homogeneous environment (i.e. agar), finding that rhizomorph systems of the more parasitic species, A. mellea, A. ostoyae, and A. tabescens, lacked melanin and the approximately cylindrical cord-like form observed in the field. In contrast, rhizomorph systems of the more saprotrophic species, A. calvescens, A. gallica, and A. sinapina, developed radially resembling those in the field. For the three saprotrophic Armillaria species, the number of rhizomorph tips, total rhizomorph length and total rhizomorph surface area were significantly positively correlated with increasing rhizomorph system diameter and elapsed time in two developmental tests. However, the fractal dimension (D), used as a measure of foraging intensity, was temporally invariable, suggesting that one component of foraging behaviour is innate. In a heterogeneous environment (i.e. sand) and in the absence of a potential nutrient source, we observed that rhizomorph systems of A. gallica most often developed asymmetrically. While rhizomorph foraging was unresponsive to the lateral placement of an uncolonised stem segment, we were able to demonstrate directional growth toward an uncolonised Quercus velutina stem segment placed above or below the colonised source stem segment. When neighboring rhizomorph systems were conspecific genets of A. gallica, we observed that the growth of one rhizomorph system was directed toward zones unoccupied by its neighbour. However, the foraging intensity of the neighbouring genets, as measured by fractal dimension (D), was unaffected by the proximity of a neighbour. When neighbouring rhizomorph systems represented different species (A. gallica and A. mellea), A. gallica rhizomorph systems produced more total length and more foraging tips but concentrated their rhizomorph production away from the neighbouring A. mellea genet. In contrast, A. mellea rhizomorph systems produced significantly more foraging tips per unit length, both overall and in the zone of confrontation with the neighbouring A. gallica genet. Our observations are consistent with field observations of territoriality among Armillaria genets, and provide evidence that rhizomorph systems of more parasitic Armillaria spp. are able to compete effectively with the larger rhizomorph systems of more saprotrophic Armillaria species. PMID:16279413

Mihail, Jeanne D; Bruhn, Johann N

2005-11-01

117

Trail geometry gives polarity to ant foraging networks  

Microsoft Academic Search

Pheromone trails are used by many ants to guide foragers between nest and food. But how does a forager that has become displaced from a trail know which way to go on rejoining the trail? A laden forager, for example, should walk towards the nest. Polarized trails would enable ants to choose the appropriate direction, thereby saving time and reducing

Duncan E. Jackson; Mike Holcombe; Francis L. W. Ratnieks

2004-01-01

118

Interactions Among Forages and Nonforage Fiber Sources1  

Microsoft Academic Search

Source, amount, and physical characteristics of dietary forage can interact with nonforage fiber sources and influence ruminal and total tract fiber digestion, passage, and performance of dairy cows fed diets containing substantial nonforage fiber in place of forage. Dietary NDF from forage can be reduced to ?60% and still provide sufficient amounts of effective fiber for FCM production that is

R. J. Grant

1997-01-01

119

Piping Plover Foraging-Site Selection on the Missouri River  

Microsoft Academic Search

Selection of a foraging site entails costs and benefits which are reflected in survival and reproductive success. We studied Piping Plover ( Charadrius melodus ) foraging-site selection during the breeding season (2001- 2003) on the Missouri River and examined the relationship between site selection and invertebrate abundance in- dices within habitats. Foraging adult plovers selected protected shoreline (inter-sandbar channels, inlets,

D ANIELLE L E F ER; J AMES D. F RASER; ASEY D. K RUSE

120

Measuring the productivity of grazing and foraging livestock  

Microsoft Academic Search

The problems of defining and measuring the productivity of grazing and foraging livestock are reviewed. It is proposed that the economic margin per unit of forage is an appropriate index of productivity for many livestock production systems, allowing comparison of the efficiency with which different types of livestock in different management systems produce economic margins from a forage resource. A

A. D. James; A. B. Carles

1996-01-01

121

Fungal Cellulase and Hemicellulase Prediction of Forage Digestibility 1  

Microsoft Academic Search

An enzymatic procedure using Tri- cboderrna viride carbohydrases, a fungal hemicellulase, and pepsin was developed to provide a laboratory method for pre- dicting forage digestibility. The amount of forage dry matter solubilized by en- zymes and incubation buffer was less than that in vivo or by in vitro fermenta- tion by rumen microorganisms. Total forage dry matter solubilized by the

R. McQUEEN; P. J. VAN SOEST

1974-01-01

122

Bumblebee flight distances in relation to the forage landscape  

Microsoft Academic Search

Summary 1. Foraging range is a key aspect of the ecology of 'central place foragers'. Estimating how far bees fly under different circumstances is essential for predicting colony success, and for estimating bee-mediated gene flow between plant populations. It is likely to be strongly influenced by forage distribution, something that is hard to quantify in all but the simplest landscapes;

Juliet L. Osborne; Andrew P. Martin; Norman L. Carreck; Jennifer L. Swain; Mairi E. Knight; Dave Goulson; Roddy J. Hale; Roy A. Sanderson

2008-01-01

123

Interactions between shoal size and conformity in guppy social foraging  

Microsoft Academic Search

Previous experimental studies have established that shoaling fish forage more effectively in large than small groups. We investigated how shoal size affects the foraging efficiency of laboratory populations of the guppy, Poecilia reticulata, exposed to different foraging tasks. Experiment 1 confirmed the prediction that in open water the first fish and focal fish of larger shoals locate food faster than

Rachel L. Day; Tom MacDonald; Culum Brown; Kevin N. Laland; Simon M. Reader

2001-01-01

124

PERFORMANCE OF FORAGE SOYBEAN LINES IN THE SOUTHERN GREAT PLAINS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pasture for livestock is often in short supply during the late summer in the southern Great Plains. The objective of this study was to compare seasonal forage production patterns, forage quality, and grain yield of three recently developed forage soybean cultivars ('Donegal', 'Derry' and 'Tyrone') ...

125

NUTRITIONAL AND SEED RESPONSES OF FORAGE KOCHIA TO RUMINAL INCUBATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Forage kochia (Kochia prostrata) is an introduced perennial subshrub that may potentially provide high-quality winter forage for livestock while reducing the severity of wildland fires fueled by invasive annual grasses like cheatgrass. There is a concern that forage kochia may spread to native rang...

126

EFFECTS OF FORAGE MANAGEMENT ON PASTURE PRODUCTIVITY AND PHOSPHORUS CONTENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objectives of the current study were to determine the amounts of above- and below-ground plant biomass production, phosphorus (P) uptake by forage, and P concentration of cool-season grass forage as influenced by management and season. Five forage management treatments were evaluated over three...

127

CAN FORAGE MIXTURES IMPROVE PRODUCTIVITY OF GRAZING DAIRY COWS?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Twenty multiparous Holstein cows in mid-lactation grazed pastures of four forage mixtures in a 13-week study repeated during two grazing seasons to determine if forage mixtures affected intake and productivity of lactating dairy cows. The forage mixtures were: 1) orchardgrass plus white clover (2...

128

Honeybees foraging response in genetically diversified opium poppy  

Microsoft Academic Search

Studies were carried out on honeybees foraging on plant flowers. Results showed significantly higher foraging response of honeybees (Apis mellifera) in genetically divergent narcotic plant opium poppy (Papaver somniferum). Of the 18 mutants and two locally adapted cultivars of diverse genotypes screened, eight revealed significantly greater foraging response manifesting honeybee’s preference towards specific plant morphotypes. The number of flower bloom

H. K. Srivastava; Dwijendra Singh

2006-01-01

129

PERFORMANCE OF FORAGE SOYBEANS IN THE SOUTHERN GREAT PLAINS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pasture for livestock in the southern Great Plains is often in short supply during the late summer. This study compared seasonal patterns in forage production, forage quality, and seed yield of three recently developed cultivars of forage soybean (Glycine max L.) (Donegal, Derry and Tyrone) to the ...

130

An elementary social information foraging model  

Microsoft Academic Search

User interfaces and information systems have become increasingly social in recent years, aimed at supporting the decentralized, cooperative production and use of content. A theory that predicts the impact of interface and interaction designs on such factors as participation rates and knowledge discovery is likely to be useful. This paper reviews a variety of observed phenomena in social information foraging

Peter Pirolli

2009-01-01

131

Memory dynamics and foraging strategies of honeybees  

Microsoft Academic Search

Summary The foraging behavior of a single bee in a patch of four electronic flower dummies (feeders) was studied with the aim of analyzing the informational components in the choice process. In different experimental combinations of reward rates, color marks, odors and distances of the feeders, the behavior of the test bee was monitored by a computer in real time

Uwe Greggers; Randolf Menzel

1993-01-01

132

Balancing organization and flexibility in foraging dynamics.  

PubMed

Proper pattern organization and reorganization are central problems facing many biological networks which thrive in fluctuating environments. However, in many cases the mechanisms that organize system activity oppose those that support behavioral flexibility. Thus, a balance between pattern organization and pattern flexibility is critically important for overall biological fitness. We study this balance in the foraging strategies of ant colonies exploiting food in dynamic environments. We present discrete time and space simulations of colony activity that uses a pheromone-based recruitment strategy biasing foraging towards a food source. After food relocation, the pheromone must evaporate sufficiently before foraging can shift colony attention to a new food source. The amount of food consumed within the dynamic environment depends non-monotonically on the pheromone evaporation time constant-with maximal consumption occurring at a time constant which balances trail formation and trail flexibility. A deterministic, 'mean field' model of pheromone and foragers on trails mimics our colony simulations. This reduced framework captures the essence of the flexibility-organization balance, and relates optimal pheromone evaporation to the timescale of the dynamic environment. We expect that the principles exposed in our study will generalize and motivate novel analysis across a broad range systems biology. PMID:20627107

Tabone, Michaelangelo; Ermentrout, Bard; Doiron, Brent

2010-07-11

133

Forages: The Foundation for Equine Gastrointestinal Health  

Microsoft Academic Search

Horses have evolved over millions of years as grazers, with specialized digestive tracts adapted to digest and utilize diets containing high levels of plant fiber. They are capable of processing large quanti- ties of forage to meet their nutrient demands. In an attempt to maximize growth or productivity, horses are often fed diets that also contain high levels of grains

JOE D. PAGAN

134

HARVESTING WINTER FORAGES TO EXTRACT MANURE NUTRIENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Harvested hay captures soil manure nutrients which, if not utilized, could cause pollution of surface water or aquifer. This study determined yields of hay and N,P,K,Mg,Mn,Ca,Fe,Zn, and Cu of three winter forages in five harvesting systems. Dormant bermudagrass [Cynodon dactylon (L.)Pers.] sod regul...

135

Effect of Leaf Rust on Cereal Forage  

Microsoft Academic Search

FEW investigators have examined the effect of leaf rust on yield, chemical composition and nutritive value of cereal forage. This situation is unexpected in view of the large acreage of cereals devoted to sheep and cattle grazing in many countries. However, the reviews of Allen1 and of Chester2 indicate that invasion of a susceptible host by an obligate parasite such

A. F. Greenall

1957-01-01

136

Diffusion of foraging innovations in the guppy  

Microsoft Academic Search

The way in which novel learned behaviour patterns spread through animal populations remains poorly understood, despite extensive field research and the recognition that such processes play an important role in the behavioural development, social interactions and evolution of many animal species. We conducted a series of controlled diffusions of foraging information in replicate experimental populations of the guppy, Poecilia reticulata.

Simon M. Reader; Kevin N. Laland

2000-01-01

137

Social organization and foraging in emballonurid bats  

Microsoft Academic Search

1.Five species of emballonurid bats (Rhynchonycteris naso, Saccopteryx leptura, Balantiopteryx plicata, Saccopteryx bilineata, and Peropteryx kappleri), were studied in Costa Rica and Trinidad. Stomach contents suggest that prey size generally increases for bat body size, but within these species there is considerable overlap. R. naso, S. leptura, and P. kappleri each appear to be specialized for foraging in a particular

J. W. Bradbury; S. L. Vehrencamp

1976-01-01

138

SWITCHGRASS FOR BIOFUEL, FORAGE, AND MUSHROOMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Switchgrass (Panicum virgatum L.), a native perennial warm-season grass, is used as a forage and conservation plant in the eastern USA. During the last 15 years switchgrass has received much attention as a model energy crop. Attributes of switchgrass desirable for bioenergy cropping include its demo...

139

REPORT The dynamics of infant visual foraging  

Microsoft Academic Search

Human infants actively forage for visual information from the moment of birth onward. Although we know a great deal about how stimulus characteristics influence looking behavior in the first few postnatal weeks, we know much less about the intrinsic dynamics of the behavior. Here we show that a simple stochastic dynamical system acts quantitatively like 4-week-old infants on a range

Steven S. Robertson; John Guckenheimer; Amy M. Masnick; Leigh F. Bacher

140

How patrollers set foraging direction in harvester ants.  

PubMed

Recruitment to food or nest sites is well known in ants; the recruiting ants lay a chemical trail that other ants follow to the target site, or they walk with other ants to the target site. Here we report that a different process determines foraging direction in the harvester ant Pogonomyrmex barbatus. Each day, the colony chooses from among up to eight distinct foraging trails; colonies use different trails on different days. Here we show that the patrollers regulate the direction taken by foragers each day by depositing Dufour's secretions onto a sector of the nest mound about 20 cm long and leading to the beginning of a foraging trail. The patrollers do not recruit foragers all the way to food sources, which may be up to 20 m away. Fewer foragers traveled along a trail if patrollers had no access to the sector of the nest mound leading to that trail. Adding Dufour's gland extract to patroller-free sectors of the nest mound rescued foraging in that direction, while poison gland extract did not. We also found that in the absence of patrollers, most foragers used the direction they had used on the previous day. Thus, the colony's 30-50 patrollers act as gatekeepers for thousands of foragers and choose a foraging direction, but they do not recruit and lead foragers all the way to a food source. PMID:18171176

Greene, Michael J; Gordon, Deborah M

2007-12-01

141

The regulation of ant colony foraging activity without spatial information.  

PubMed

Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus) colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony. PMID:22927811

Prabhakar, Balaji; Dektar, Katherine N; Gordon, Deborah M

2012-08-23

142

Anterior cingulate cortical lesion attenuates food foraging in rats.  

PubMed

We have developed a novel laboratory rodent model to detect competitive, non-competitive and no-hurdle foraging behaviors as seen in natural environment. However, it is not clear which brain region is important for the food foraging activity. In the present study, we evaluated the effect of lesions in the bilateral anterior cingulate cortex (ACC) on the rat food foraging behavior with the established model. In contrast to the sham lesion group (saline microinjection into the ACC), bilateral complete ACC chemical lesions (kainic acid microinjection into the ACC) significantly decreased the amount of foraged food in the competitive food foraging tests, non-competitive or no-hurdle foraging test. Moreover, the deficit of the food foraging activity was more prominent in the competitive food foraging test than in the non-competitive food and no-hurdle foraging test after ACC lesions. No alterations after ACC lesions were found in other behaviors including elevated plus-maze test (EPM), forced swimming test (FST), open field test (OFT), sucrose preference test and exploratory behavior. These findings suggest that the ACC mediate the food foraging-related behaviors. PMID:22683801

Li, Fang; Li, Mingbo; Cao, Wenyu; Xu, Yang; Luo, Yanwei; Zhong, Xiaolin; Zhang, Jianyi; Dai, Ruping; Zhou, Xin-Fu; Li, Zhiyuan; Li, Changqi

2012-06-06

143

Attentional dynamics of infant visual foraging.  

PubMed

Young infants actively gather information about their world through visual foraging, but the dynamics of this important behavior is poorly understood, partly because developmental scientists have often equated its essential components, looking and attending. Here we describe a method for simultaneously tracking spatial attention to fixated and nonfixated locations during free looking in 12-week-old infants using steady-state visual evoked potentials (SSVEPs). Using this method, we found that the sequence of locations an infant inspects during free looking reflects a momentary bias away from locations that were recently the target of covert attention, quickly followed by the redirection of attention--in advance of gaze--to the next target of fixation. The result is a pattern of visual foraging that is likely to support efficient exploration of complex environments by facilitating the inspection of new locations in real time. PMID:22733754

Robertson, Steven S; Watamura, Sarah Enos; Wilbourn, Makeba Parramore

2012-06-25

144

Uncovering the complexity of ant foraging trails.  

PubMed

The common garden ant Lasius niger use both trail pheromones and memory of past visits to navigate to and from food sources. In a recent paper we demonstrated a synergistic effect between route memory and trail pheromones: the presence of trail pheromones results in experienced ants walking straighter and faster. We also found that experienced ants leaving a pheromone trail deposit less pheromone. Here we focus on another finding of the experiment: the presence of cuticular hydrocarbons (CHCs), which are used as home range markers by ants, also affects pheromone deposition behavior. When walking on a trail on which CHCs are present but trail pheromones are not, experienced foragers deposit less pheromone on the outward journey than on the return journey. The regulatory mechanisms ants use during foraging and recruitment behavior is subtle and complex, affected by multiple interacting factors such as route memory, travel direction and the presence trail pheromone and home-range markings. PMID:22482017

Czaczkes, Tomer J; Grüter, Christoph; Jones, Sam M; Ratnieks, Francis L W

2012-01-01

145

Uncovering the complexity of ant foraging trails  

PubMed Central

The common garden ant Lasius niger use both trail pheromones and memory of past visits to navigate to and from food sources. In a recent paper we demonstrated a synergistic effect between route memory and trail pheromones: the presence of trail pheromones results in experienced ants walking straighter and faster. We also found that experienced ants leaving a pheromone trail deposit less pheromone. Here we focus on another finding of the experiment: the presence of cuticular hydrocarbons (CHCs), which are used as home range markers by ants, also affects pheromone deposition behavior. When walking on a trail on which CHCs are present but trail pheromones are not, experienced foragers deposit less pheromone on the outward journey than on the return journey. The regulatory mechanisms ants use during foraging and recruitment behavior is subtle and complex, affected by multiple interacting factors such as route memory, travel direction and the presence trail pheromone and home-range markings.

Gruter, Christoph; Jones, Sam M.; Ratnieks, Francis L.W.

2012-01-01

146

Tactile learning in resin foraging honeybees  

Microsoft Academic Search

Honeybees harvest and use plant resins in a mixture called propolis to seal cracks and smooth surfaces in the nest architecture.\\u000a Resins in the nest may be important in maintaining a healthy colony due to their antimicrobial properties. This study had\\u000a two main objectives: (1) Provide initial insight on the learning capabilities of resin foraging honeybees; (2) analyze the\\u000a sensitivity

Michael Simone-Finstrom; Joel Gardner; Marla Spivak

2010-01-01

147

Foraging by generalist grasshoppers: two different strategies  

Microsoft Academic Search

Abstract. Observations of foraging activities were conducted on two species of generalist grasshoppers that are cryptic on foliage,Schistocerca nitensandS.shoshone, which have overlapping distributions in the southwestern region of the U.S.A. Patterns of activity, feed lengths, food choice and switching between host plants were examined by continuous recording of individuals for up to 8h each in the field. Long feeding bouts

P. CHAMBERS; G. SWORD; J. E. ANGEL; S. BEHMER; E. A. BERNAYS

1996-01-01

148

Size, foraging, and food web structure  

PubMed Central

Understanding what structures ecological communities is vital to answering questions about extinctions, environmental change, trophic cascades, and ecosystem functioning. Optimal foraging theory was conceived to increase such understanding by providing a framework with which to predict species interactions and resulting community structure. Here, we use an optimal foraging model and allometries of foraging variables to predict the structure of real food webs. The qualitative structure of the resulting model provides a more mechanistic basis for the phenomenological rules of previous models. Quantitative analyses show that the model predicts up to 65% of the links in real food webs. The deterministic nature of the model allows analysis of the model's successes and failures in predicting particular interactions. Predacious and herbivorous feeding interactions are better predicted than pathogenic, parasitoid, and parasitic interactions. Results also indicate that accurate prediction and modeling of some food webs will require incorporating traits other than body size and diet choice models specific to different types of feeding interaction. The model results support the hypothesis that individual behavior, subject to natural selection, determines individual diets and that food web structure is the sum of these individual decisions.

Petchey, Owen L.; Beckerman, Andrew P.; Riede, Jens O.; Warren, Philip H.

2008-01-01

149

Forage kochia ( Kochia prostrata) for fall and winter grazing  

Microsoft Academic Search

Forage kochia (Kochia prostrata (L.) Schrad.), also known as prostrate kochia, or prostrate summer cypress is a long-lived, perennial, semi-evergreen, half-shrub well adapted to the temperate, semiarid and arid regions of central Asia and the western U.S. In these areas it has proven to be a valuable forage plant for sheep, goats, camels, cattle, and horses. Forage kochia is a

B. L. Waldron; J.-S. Eun; D. R. ZoBell; K. C. Olson

2010-01-01

150

Nutrient compensatory foraging in a free-living social insect  

Microsoft Academic Search

The geometric framework model predicts that animal foraging decisions are influenced by their dietary history, with animals\\u000a targeting a combination of essential nutrients through compensatory foraging. We provide experimental confirmation of nutrient-specific\\u000a compensatory foraging in a natural, free-living population of social insects by supplementing their diet with sources of protein-\\u000a or carbohydrate-rich food. Colonies of the ant Iridomyrmex suchieri were

Keri L. Christensen; Anthony P. Gallacher; Lizzie Martin; Desmond Tong; Mark A. Elgar

2010-01-01

151

Bee foraging ranges and their relationship to body size  

Microsoft Academic Search

Bees are the most important pollinator taxon; therefore, understanding the scale at which they forage has important ecological\\u000a implications and conservation applications. The foraging ranges for most bee species are unknown. Foraging distance information\\u000a is critical for understanding the scale at which bee populations respond to the landscape, assessing the role of bee pollinators\\u000a in affecting plant population structure, planning

Sarah S. Greenleaf; Neal M. Williams; Rachael Winfree; Claire Kremen

2007-01-01

152

Mercury bioaccumulation and risk to three waterbird foraging guilds is influenced by foraging ecology and breeding stage  

Microsoft Academic Search

We evaluated mercury (Hg) in five waterbird species representing three foraging guilds in San Francisco Bay, CA. Fish-eating birds (Forster's and Caspian terns) had the highest Hg concentrations in thier tissues, but concentrations in an invertebrate-foraging shorebird (black-necked stilt) were also elevated. Foraging habitat was important for Hg exposure as illustrated by within-guild differences, where species more associated with marshes

Collin A. Eagles-Smith; Joshua T. Ackerman; Susan E. W. De La Cruz; John Y. Takekawa

2009-01-01

153

The impact of weather on kingbird foraging behavior  

SciTech Connect

Foraging data on Eastern Kingbirds (Tyrannus tyrannus) were collected during the early breeding season in eastern Kansas to test the hypothesis that foraging rate and other aspects of foraging behavior vary with weather. Foraging characteristics of five additional kingbird species were also examined to assess Fitzpatrick's 1980 generalization that kingbirds (Tyrannus spp.) are aerial hawking specialists. In Eastern Kingbirds, total foraging rate was independent of air temperature, cloud cover, wind speed, and time of day, but the rate of aerial hawking varied directly with air temperature and inversely with cloud cover (both P < 0.05). Effects of the two variables were additive. The percentage of foraging movements that were aerial hawks also increased with temperature and declined with cloud cover, and hover-gleaning and perch-to-ground sallying were observed mainly during cloudy weather. Sally (i.e., foraging flight) distance correlated directly with perch height and air temperature, and large insects were captured almost exclusively in long upward or horizontal flights. I interpret these data to indicate that foraging behavior and the capture of large, flying insects depends on weather because of how it affects the activity of insect prey. Foraging data on kingbirds support Fitzpatrick's generalization, but the relative use of aerial hawking varies considerably among species. Resident Tropical Kingbirds (T. melancholicus) are the most specialized foragers, whereas the migrant and widely distributed Eastern Kingbird appears to be the most generalized. Certain habitats also appear to favor the use of particular foraging methods (e.g., outward striking in grasslands, and perch-to-ground sallying in drier, open habitats).

Murphy, M.T. (Museum of Natural History, The University of Kansas, Lawrence, KS 66045)

1987-01-01

154

Evaluation of endemic leguminous forage shrubs from the Canary Islands. 3 Organic constituents and forage digestibility  

Microsoft Academic Search

From 1999 to 2000, four leguminous shrub species endemic to the Canary Islands, Chamaecytisus palmensis (tagasaste), Teline canariensis, Teline osyrioides sericea and Teline osyrioides osyrioides, were studied as a source of animal forage in two different experiments. One experiment was carried out on a crop planted at a density of 5142 shrubs\\/ha, established in La Laguna (Tenerife, Spain) at 550

E. Chinea

2008-01-01

155

BEEF CATTLE FORAGE CONDITIONING OF 6 NORTHERN GREAT BASIN GRASSES: REGROWTH FORAGE QUALITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Recent efforts to verify Anderson and Scherzinger's 1975 livestock forage conditioning hypothesis have generated mixed results. Our objective was to evaluate mid-summer and early-fall crude protein (CP) content of bluebunch wheatgrass (Agropyron spicatum [Pursh] Scribn. & Smith), Idaho fescue (Fest...

156

Social foraging in honey bees: how nectar foragers assess their colony's nutritional status  

Microsoft Academic Search

A honey bee colony operates as a tightly integrated unit of behavioral action. One manifestation of this in the context of foraging is a colony's ability to adjust its selectivity among nectar sources in relation to its nutritional status. When a colony's food situation is good, it exploits only highly profitable patches of flowers, but when its situation is poor,

Thomas D. Seeley

1989-01-01

157

Multimodal Floral Signals and Moth Foraging Decisions  

PubMed Central

Background Combinations of floral traits – which operate as attractive signals to pollinators – act on multiple sensory modalities. For Manduca sexta hawkmoths, how learning modifies foraging decisions in response to those traits remains untested, and the contribution of visual and olfactory floral displays on behavior remains unclear. Methodology/Principal Findings Using M. sexta and the floral traits of two important nectar resources in southwestern USA, Datura wrightii and Agave palmeri, we examined the relative importance of olfactory and visual signals. Natural visual and olfactory cues from D. wrightii and A. palmeri flowers permits testing the cues at their native intensities and composition – a contrast to many studies that have used artificial stimuli (essential oils, single odorants) that are less ecologically relevant. Results from a series of two-choice assays where the olfactory and visual floral displays were manipulated showed that naïve hawkmoths preferred flowers displaying both olfactory and visual cues. Furthermore, experiments using A. palmeri flowers – a species that is not very attractive to hawkmoths – showed that the visual and olfactory displays did not have synergistic effects. The combination of olfactory and visual display of D. wrightii, however – a flower that is highly attractive to naïve hawkmoths – did influence the time moths spent feeding from the flowers. The importance of the olfactory and visual signals were further demonstrated in learning experiments in which experienced moths, when exposed to uncoupled floral displays, ultimately chose flowers based on the previously experienced olfactory, and not visual, signals. These moths, however, had significantly longer decision times than moths exposed to coupled floral displays. Conclusions/Significance These results highlight the importance of specific sensory modalities for foraging hawkmoths while also suggesting that they learn the floral displays as combinatorial signals and use the integrated floral traits from their memory traces to mediate future foraging decisions.

Riffell, Jeffrey A.; Alarcon, Ruben

2013-01-01

158

Good foragers can also be good at detecting predators  

Microsoft Academic Search

The degree to which foraging and vigilance are mutually exclusive is crucial to understanding the manage- ment of the predation and starvation risk trade-off in animals. We tested whether wild-caught captive chaffinches that feed at a higher rate do so at the expense of their speed in responding to a model spar- rowhawk flying nearby, and whether consistently good foragers

W. Cresswell; J. L. Quinn; M. J. Whittingham; S. Butler

2003-01-01

159

Experimental Study of the Dynamics of Foraging Ants  

Microsoft Academic Search

We study the search paths of foraging ants in order to describe their behavior mathematically. Ants have become popular as simple agents in models of artificial life. Here, the ant is presented the problem of finding food when no food cues are present. In this experiment, individual ants (Formicinae lasius flavus) are allowed to forage on a two-dimensional textured surface

J. I. Walker; R. P. Fetzner; G. W. Baxter

2006-01-01

160

Foraging behavior of fish schools via diffusion adaptation  

Microsoft Academic Search

Fish organize themselves into schools as a way to defend against predators and improve foraging efficiency. In this work we develop a model for food foraging and explain how a school of fish can move as a group if every fish were to employ a distributed strategy, known as diffusion adaptation. The algorithm assumes the fish sense the general direction

Sheng-Yuan Tu; Ali H. Sayed

2010-01-01

161

DIGESTIBILITY AND FIBER OF A FORAGE BERMUDAGRASS CORE COLLECTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bermudagrass is the most important warm-season grass forage for the South. Cultivars with good quality traits such as high dry matter digestibility have translated into higher daily gains for beef and improved milk production in dairy cattle. A forage bermudagrass core collection consisting of 168...

162

Group size and foraging efficiency in yellow baboons  

Microsoft Academic Search

I studied the foraging behaviour of adults in three different-sized groups of yellow baboons (Papio cynocephalus) at Amboseli National Park in Kenya to assess the relationship between group size and foraging efficiency in this species. Study groups ranged in size from 8 to 44 members; within each group, I collected feeding data for the dominant adult male, the highest ranking

Peter B. Stacey

1986-01-01

163

Animal Foraging and the Evolution of Goal-Directed Cognition  

ERIC Educational Resources Information Center

|Foraging-and feeding-related behaviors across eumetazoans share similar molecular mechanisms, suggesting the early evolution of an optimal foraging behavior called area-restricted search (ARS), involving mechanisms of dopamine and glutamate in the modulation of behavioral focus. Similar mechanisms in the vertebrate basal ganglia control motor…

Hills, Thomas T.

2006-01-01

164

Evapotranspiration of corn and forage sorghum for silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

In the U.S. Southern High Plains, dairies have expanded and have increased the regional demand for forage and silage. The objectives were to measure water use and determine crop coefficients for corn (Zea mays L.) and forage sorghum (Sorghum bicolor (L.) Moench) produced for silage on the Southern ...

165

Group foraging by a stream minnow: shoals or aggregations?  

USGS Publications Warehouse

The importance of social attraction in the formation of foraging groups was examined for a stream-dwelling cyprinid, the rosyside dace, Clinostomus funduloides. Dace arrivals and departures at natural foraging sites were monitored and tested for (1) tendency of dace to travel in groups, and (2) dependency of arrival and departure rates on group size. Dace usually entered and departed foraging sites independently of each other. Group size usually affected neither arrival rate nor departure probability. Thus, attraction among dace appeared weak; foraging groups most often resulted from dace aggregating in preferred foraging sites. The strongest evidence of social attraction was during autumn, when dace departure probability often decreased with increasing group size, possibly in response to increased threat of predation by a seasonally occurring predator. Dace also rarely avoided conspecifics, except when an aggressive individual defended a foraging site. Otherwise, there was little evidence of exploitative competition among dace for drifting prey or of foraging benefits in groups, because group size usually did not affect individual feeding rates. These results suggest that the benefits of group foraging demonstrated under laboratory conditions in other studies may not always apply to field conditions.

Freeman, M. C.; Grossman, G. D.

1992-01-01

166

FLIGHT STRATEGIES OF MIGRATING OSPREY: FASTING VS. FORAGING  

Microsoft Academic Search

We developed energetics models to predict migration times and fat consumption rates of osprey (Pandion haliaetus) migrating south from their breeding grounds in the Intermountain West of North America. In these models we simulated three migration strategies: fasting, foraging at several mid-migration stopovers (jump strategy) and frequent foraging at stopovers (hop strategy). Because these piscivores appear to migrate predominantly over

GRADY L. CANDLERAND; PATRICIA L. KENNEDY

167

Compatibility of Forages and Livestock with Plantation Crops  

Microsoft Academic Search

There is an inherent complementarity between plantation crops and the raising of ruminant livestock. The integration of ruminants into plantation crops is most successful when both improved management of the crop and an additional income are possible. Factors affecting the competitive effects of forages on plantation crops are species of forage used, application of fertilizer, and the recycling of nutrients

W. W. Stür; H. M. Shelton

168

Polyphenols and agriculture: beneficial effects of proanthocyanidins in forages  

Microsoft Academic Search

Proanthocyanidins (PA), also known as condensed tannins, belong to the oldest of plant secondary metabolites. These compounds are widespread in woody plants, but are also found in certain forages. Proanthocyanidins can exert effects in organisms because of their ability to complex with proteins. Forages containing moderate concentrations of PA (2–4% DM) can exert beneficial effects on protein metabolism in sheep,

Rob J. Aerts; Tom N. Barry; Warren C. McNabb

1999-01-01

169

Green Crab (Carcinus maenas) Foraging Efficiency Reduced by Fast Flows  

Microsoft Academic Search

Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is

Elizabeth M. Robinson; Delbert L. Smee; Geoffrey C. Trussell

2011-01-01

170

Effects of Blue Oak Canopy on Annual Forage Production1  

Microsoft Academic Search

Production of annual forage was compared at four sites under four blue oak (Quercus douglasii) canopy levels (0, 25, 50, and 75 percent), over 5 years, at the University of California Sierra Foothill Research and Extension Center in Yuba County, California. Long-term annual precipitation averages 28.5 inches. Significant differences in herbaceous forage production occurred among years, with the highest rainfall

J. Michael Connor; Bob L. Willoughby

171

Relationship between shrub cover and available forage in Mediterranean shrublands  

Microsoft Academic Search

Shrublands with kermes oak (Quercus coccifera L.) as a dominant species play an important role in the nutrition of grazing animals in the Mediterranean region during all seasons of the year. Their proper management, however, is inhibited by the lack of easy and inexpensive methods for measuring available forage. In this paper, the spatial distribution of available forage as well

P. D. Platis; V. P. Papanastasis

2003-01-01

172

The Value of Information in Central-Place Foraging  

Microsoft Academic Search

We consider a central place forager with two qualitatively different types of food sources; type 1 sources are always available whereas type 2 sources become available intermittently and this availability is signalled by information present at the central place. Source 1 is modelled using a standard patch foraging model whereas source 2 is modelled somewhat schematically in terms of the

E. J. Collins; A. I. Houston; J. M. McNamara

173

Central place foraging in the Eastern chipmunk, Tamias striatus  

Microsoft Academic Search

Orians & Pearson (1979) considered the optimal foraging strategies of 'central place foragers', animals that repeatedly return with their food to a fixed location. We tested some of their predictions on eastern chipmunks, Tamias striatus. The rate of cheek pouch loading declines as the pouches fill; thus the optimal load size may vary, depending on the time required to travel

DONALD L. KRAMER; WILLIAM NOWELL

1980-01-01

174

Nest defense and central place foraging: A model and experiment  

Microsoft Academic Search

A graphical model presented here indicates that a nest-defending forager should stay closer to its nest, forage for shorter times per patch, and deliver smaller loads than predicated for delivery rate maximization. The effect is more pronounced farther from the nest, so that if nest defense is especially important, the predator should leave far patches sooner than near ones, and

Steven Martindale

1982-01-01

175

Testing Optimal Foraging Theory Using Bird Predation on Goldenrod Galls  

ERIC Educational Resources Information Center

|All animals must make choices regarding what foods to eat, where to eat, and how much time to spend feeding. Optimal foraging theory explains these behaviors in terms of costs and benefits. This laboratory exercise focuses on optimal foraging theory by investigating the winter feeding behavior of birds on the goldenrod gall fly by comparing…

Yahnke, Christopher J.

2006-01-01

176

SEASONAL MORPHOLOGY AND FORAGE QUALITY OF TEMPERATE GRASSES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Forage quality of grazed swards is closely associated with the contribution and quality of morphological components. We determined leaf and stem fraction dry matter and forage quality trends for temperate perennial grasses at two Wisconsin locations. After reaching 15 to 20 cm height, primary spri...

177

Threat-sensitive foraging by larval threespine sticklebacks ( Gasterosteus aculeatus )  

Microsoft Academic Search

The threat-sensitive predator avoidance hypothesis predicts that prey can assess the relative threat posed by a predator and adjust their behaviour to reflect the magnitude of the threat. We tested the ability of larval threespine sticklebacks to adjust their foraging in the presence of predators by exposing them to conspecific predators of various sizes and recording their foraging and predator

Todd D. Bishop; Joseph A. Brown

1992-01-01

178

Marker assisted selection in forage breeding: a broadened vision  

Technology Transfer Automated Retrieval System (TEKTRAN)

Forage breeding programs do not yet widely use molecular markers. Reasons include meager breeding program resources and mass selection’s ease and cost competitive nature (despite its extreme inefficiency). Most traditional forage breeding methods are based on 'Delta'G = kh'sigma-sub-A' (i.e., select...

179

The use of edge habitats by commuting and foraging bats  

Microsoft Academic Search

Travelling routes and foraging areas of many bat species are mainly along edge habitats, such as treelines, hedgerows, forest edges, and canal banks. This thesis deals with the effects of density, configuration, and structural features of edge habitats on the occurrence of bats. Four hypothetical functions of edge habitats for bats were studied: foraging areas, shelter from wind, shelter from

B. Verboom

1998-01-01

180

FORAGING ECOLOGY OF NESTING BALD EAGLES IN ARIZONA  

Microsoft Academic Search

We studied foraging ecology of nesting Bald Eagles (Haliaeetus leucocephalus) in Arizona during 1987-89, with emphasis on the influence of dams and river flow regulation. We examined diet, foraging modes, habitat selection, fish abundance, and factors associated with fish availability. Based on biomass, prey remains yielded 76% fish, 14% mammals, and 10% birds. On rivers, eagles primarily caught live fish

W. GRAINGER HUNT; RONALD E. JACCV; DANIEL E. DRISCOLL; EDWARD W. BIANCHI

2002-01-01

181

Individual variation in winter foraging of black-capped chickadees  

Microsoft Academic Search

Wintering black-capped chickadees (Paridae: Parus atricapillus) in northwestern Massachusetts showed a high degree of individual variation in foraging behavior. After accounting for the effects of different habitats and weather conditions, individual differences comprised 6–17% of the total observed variation in four measures of foraging location and rate of feeding. Differences between age and sex groups were not significant and explained

J. Van Buskirk; D. C. Smith

1989-01-01

182

Food and foraging behaviour of the Snares fernbird  

Microsoft Academic Search

The Snares fernbird (Bowdleria punctata caudata Buller, 1894) is an opportunistic insectivore, its prey ranging greatly in size and type. Birds forage over a wide variety of sites, including forest, tussock, boulder beaches, cliffs, penguin colonies, and floating kelp. Foraging methods vary with the prey sought, and at times birds adopt specific “search images” when hunting certain insects. Details of

H. A. Best

1979-01-01

183

Dispersed central place foraging in Australian meat ants  

Microsoft Academic Search

Summary Australian meat ants often inhabit colonies with widely dispersed nest holes, and this study examines how resource is harvested and distributed in a colony ofIridomyrmex sanguineus Smith (Formicidae: Dolichoderinae). The three principal types of foragers (tenders, honeydew transporters, scavengers) exhibited nest hole fidelity, where harvested resource was consistently delivered to the same nest hole by each foraging individual. Australian

J. D. McIver

1991-01-01

184

Adaptive Computational Chemotaxis in Bacterial Foraging Optimization: An Analysis  

Microsoft Academic Search

In his seminal paper published in 2002, Passino pointed out how individual and groups of bacteria forage for nutrients and how to model it as a distributed optimization process, which he called the bacterial foraging optimization algorithm (BFOA). One of the major driving forces of BFOA is the chemotactic movement of a virtual bacterium that models a trial solution of

Sambarta Dasgupta; Swagatam Das; Ajith Abraham; Arijit Biswas

2009-01-01

185

Alfalfa and forage kochia improve nutritive value of semiarid rangelands  

Technology Transfer Automated Retrieval System (TEKTRAN)

Improving forage quality on semiarid grazing lands of the western United States is challenging. This study compared the late summer forage quality parameters crude protein (CP) and neutral detergent fiber (NDF) of 'Vavilov' Siberian wheatgrass (Agropyron fragile). 'Mustang' Altai wildrye (Leymus ang...

186

SEASONAL DYNAMICS OF FORAGE FATTY ACIDS IN SOUTHERN WEST VIRGINIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fatty acid composition of ruminant diets influences the fatty acid profile of meat products, impacting flavor and other meat quality characteristics. An understanding of seasonal dynamics in forage fatty acids is needed to define forage systems and grazing management strategies that will result...

187

Do bumblebees (Hymenoptera: Apidae) really forage close to their nests?  

Microsoft Academic Search

This paper questions whether bumblebees really forage as close to their nests as has commonly been assumed in the bumblebee literature. Three experiments are described that involved marking and reobservation bumblebees. None of these experiments showed any tendency for bumblebees to concentrate their foraging close to (e.g., within 50 m from) the nest. Rather, the results suggested that bumblebees may

W. E. Dramstad

1996-01-01

188

Forage yield and quality differences among cool-season grasses  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rotationally-stocked, perennial cool-season grasses are often utilized at a vegetative stage of maturity. We compared the yield and forage quality of leaves, stems, and total forage of meadow fescue, orchardgrass, quackgrass, reed canarygrass, smooth bromegrass, EF (endophyte-free) and EI (endophyte...

189

Behavioural Syndrome in a Solitary Predator Is Independent of Body Size and Growth Rate  

PubMed Central

Models explaining behavioural syndromes often focus on state-dependency, linking behavioural variation to individual differences in other phenotypic features. Empirical studies are, however, rare. Here, we tested for a size and growth-dependent stable behavioural syndrome in the juvenile-stages of a solitary apex predator (pike, Esox lucius), shown as repeatable foraging behaviour across risk. Pike swimming activity, latency to prey attack, number of successful and unsuccessful prey attacks was measured during the presence/absence of visual contact with a competitor or predator. Foraging behaviour across risks was considered an appropriate indicator of boldness in this solitary predator where a trade-off between foraging behaviour and threat avoidance has been reported. Support was found for a behavioural syndrome, where the rank order differences in the foraging behaviour between individuals were maintained across time and risk situation. However, individual behaviour was independent of body size and growth in conditions of high food availability, showing no evidence to support the state-dependent personality hypothesis. The importance of a combination of spatial and temporal environmental variation for generating growth differences is highlighted.

Nyqvist, Marina J.; Gozlan, Rodolphe E.; Cucherousset, Julien; Britton, J. Robert

2012-01-01

190

Mapping of wood stork foraging habitat with satellite data  

SciTech Connect

Potential foraging sites for an endangered species, the wood stork, were identified using Landsat thematic mapper data for a section of north central Georgia and the Savannah River floodplain swamp in South Carolina. This was accomplished using innovative clustering techniques applied to known wood stork foraging sites around the Birdsville Colony in Georgia. The signatures for known sites were then geographically extended to a 1520-square-kilometer region surrounding the Birdsville Colony. Thematic maps were produced and foraging area acreages computed providing a regional assessment of existing and potential wood stork foraging sites. Approximately 1744 hectarea of potential shallow water and macrophyte foraging habitat were identified in the area surroundings the Birdsville Colony. 14 refs., 3 figs.

Jensen, J.R.; Coulter, M.; Mackey, H.E. Jr.; Hodgson, M.E.

1985-01-01

191

Does information sharing promote group foraging?  

PubMed Central

Individuals may join groups for several reasons, one of which is the possibility of sharing information about the quality of a foraging area. Sharing information in a patch-foraging scenario gives each group member an opportunity to make a more accurate estimate of the quality of the patch. In this paper we present a mathematical model in which we study the effect of group size on patch-leaving policy and per capita intake rate. In the model, group members share information equally in a random search for food. Food is distributed in patches according to a negative binomial distribution. A prediction from our model is that, the larger the group, the earlier each group member should leave the current patch. We also find that the benefit from enhanced exchange of information does not exceed the cost of sharing food with group members. The per capita intake rate decreases as the group size increases. Therefore, animals should only form groups when other factors outweigh the costs, which is easiest to achieve when the travelling time is short.

Sernland, Emma; Olsson, Ola; Holmgren, Noel M A

2003-01-01

192

Food-chain length and adaptive foraging  

PubMed Central

Food-chain length, the number of feeding links from the basal species to the top predator, is a key characteristic of biological communities. However, the determinants of food-chain length still remain controversial. While classical theory predicts that food-chain length should increase with increasing resource availability, empirical supports of this prediction are limited to those from simple, artificial microcosms. A positive resource availability–chain length relationship has seldom been observed in natural ecosystems. Here, using a theoretical model, we show that those correlations, or no relationships, may be explained by considering the dynamic food-web reconstruction induced by predator's adaptive foraging. More specifically, with foraging adaptation, the food-chain length becomes relatively invariant, or even decreases with increasing resource availability, in contrast to a non-adaptive counterpart where chain length increases with increasing resource availability; and that maximum chain length more sharply decreases with resource availability either when species richness is higher or potential link number is larger. The interactive effects of resource availability, adaptability and community complexity may explain the contradictory effects of resource availability in simple microcosms and larger ecosystems. The model also explains the recently reported positive effect of habitat size on food-chain length as a result of increased species richness and/or decreased connectance owing to interspecific spatial segregation.

Kondoh, Michio; Ninomiya, Kunihiko

2009-01-01

193

Linking Foraging Decisions to Residential Yard Bird Composition  

PubMed Central

Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays) in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation) differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs) compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards) contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity.

Lerman, Susannah B.; Warren, Paige S.; Gan, Hilary; Shochat, Eyal

2012-01-01

194

Linking foraging decisions to residential yard bird composition.  

PubMed

Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays) in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation) differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs) compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards) contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity. PMID:22927974

Lerman, Susannah B; Warren, Paige S; Gan, Hilary; Shochat, Eyal

2012-08-22

195

Predicting milk and forage intake of nursing calves.  

PubMed

A theoretical model was developed to predict forage intake of nursing calves based on peak milk level (PML) and BW using data from 39 Holstein steer calves individually fed for 200 d with milk replacer reconstituted to equal the fat and protein contents of beef cow milk. Treatment levels were amounts of reconstituted milk allowed per day based on lactation curves, which were based on PML of 2.72, 5.44, 8.16, 10.88, and 13.6 kg/d, respectively. Chopped alfalfa hay was offered for ad libitum intake to allow maximum voluntary forage consumption in addition to the reconstituted milk. We observed that calves receiving increased amounts of milk (10.88 to 13.66 kg of milk/d at peak) consumed little forage during the first 60 d of age. Their consumption of forage was also less than those calves receiving reduced quantities of milk (2.72 to 5.44 kg of peak milk/d) at the same BW because milk intake was prioritized. The forage DMI of the calf depended on calf BW and quality of the forage. Furthermore, calf BW and forage DMI was correlated with calf milk intake. A significant (P < 0.05) relationship between total DE intake (DEI) and BW was identified. A theoretical model was developed to predict forage DMI of nursing calves based on total DEI. The total DEI was estimated using PML and BW. Equations were developed to adjust forage DMI for DE content of the forage. A sensitivity analysis using Monte Carlo simulation indicated that forage DMI of grazing, nursing calves is likely to be less than 4.26 kg/d 95% of the time and that variation in BW and PML have the greatest impact on forage DMI. We concluded that equations developed in this study can be used to evaluate different cow-calf production scenarios, including matching forage quality and availability with dam milk production potential. PMID:19574576

Tedeschi, L O; Fox, D G

2009-07-02

196

Foraging behavior delays mechanically-stimulated escape responses in fish.  

PubMed

Foraging and the evasion of predators are fundamental for the survival of organisms, but they impose contrasting demands that can influence performance in each behavior. Previous studies suggested that foraging organisms may experience decreased vigilance to attacks by predators; however, little is known about the effect of foraging on escape performance with respect to the kinematics and the timing of the response. This study tested the hypothesis that engaging in foraging activities affected escape performance by comparing fast-start escape responses of silver-spotted sculpins Blepsias cirrhosus under three conditions: (1) control (no foraging involved), (2) while targeting prey, and (3) immediately after capture of prey. Escape response variables (non-locomotor and locomotor) were analyzed from high-speed videos. Responsiveness was lower immediately after capturing a prey item compared with the other two treatments, and latency of performance was higher in the control treatment than in the other two. Locomotor variables such as maximum speed, maximum acceleration, and turning rates did not show statistical differences among the three groups. Our results demonstrate that foraging can negatively affect two fundamental components of the escape response: (1) responsiveness and (2) latency of escape, suggesting that engaging in foraging may decrease an individual's ability to successfully evade predators. PMID:23624863

Bohórquez-Herrera, Jimena; Kawano, Sandy M; Domenici, Paolo

2013-04-26

197

Evaluation of endemic leguminous forage shrubs from the Canary Islands. 1 Germplasm characterisation and forage production  

Microsoft Academic Search

Four species of leguminous shrubs endemic to the Canary Islands (Spain)—Chamae?cytisus palmensis (tagasaste), Teline canariensis, Teline osyrioides sericea and Teline osyrioides osyrioides—were evaluated from 1999 to 2000 as a source of animal forage. Two experiments were undertaken. Experiment 1 involved wild populations in the natural habitat on the island of Tenerife including germplasm collection and a study of their phenology.

E. Chinea; E. Barquín

2007-01-01

198

Exploring behavior of an unusual megaherbivore: a spatially explicit foraging model of the hippopotamus  

Microsoft Academic Search

Herbivore foraging theories have been developed for and tested on herbivores across a range of sizes. Due to logistical constraints, however, little research has focused on foraging behavior of megaherbivores. Here we present a research approach that explores megaherbivore foraging behavior, and assesses the applicability of foraging theories developed on smaller herbivores to megafauna. With simulation models as reference points

Rebecca L. Lewison; Jacoby Carter

2004-01-01

199

The honey bee foraging behavior syndrome: quantifying the response threshold model of division of labor  

Microsoft Academic Search

This review focuses on how honey bee responsiveness to sucrose is related to a correlated suite of foraging traits, called the honey bee foraging behavior syndrome. Behavior syndromes are reminiscent of human personalities. In general, the honey bee foraging syndrome is characterized as bees with low sucrose response thresholds begin foraging at younger ages than bees with high sucrose response

Tanya Pankiw

2005-01-01

200

Foraging and associated behavior by Octopus cyanea Gray, 1849 on a coral atoll, French Polynesia  

Microsoft Academic Search

Individual Octopus cyanea Gray, 1849 were observed continuously while foraging over a 6 day period during daylight hours. Foraging usually occurred once early in the morning and once late in the afternoon, and successive forages did not duplicate the same routes. On average, single forages (n = 16) covered 81 m (max. 129 m), lasted 118 min (max. 6 h),

John W. Forsythe; Roger T. Hanlon

1997-01-01

201

The use of waggle dance information by honey bees throughout their foraging careers  

Microsoft Academic Search

We studied the extent to which worker honey bees acquire information from waggle dances throughout their careers as foragers. Small groups of foragers were monitored from time of orientation flights to time of death and all in-hive behaviors relating to foraging were recorded. In the context of a novice forager finding her first food source, 60% of the bees relied,

Jacobus C. Biesmeijer; Thomas D. Seeley

2005-01-01

202

Biomimicry of Social Foraging Bacteria for Distributed Optimization: Models, Principles, and Emergent Behaviors1  

Microsoft Academic Search

In this paper, we explain the social foraging behavior of E. coli and M. xanthus bacteria and develop simulation models based on the principles of foraging theory that view foraging as optimization. This provides us with novel models of their foraging behavior and with new methods for distributed nongradient optimization. Moreover, we show that the models of both species of

Y. LIU; K. M. PASSINO

2002-01-01

203

Biomimicry of Social Foraging Bacteria for Distributed Optimization: Models, Principles, and Emergent Behaviors  

Microsoft Academic Search

In this paper, we explain the social foraging behavior of E. coli and M. xanthus bacteria and develop simulation models based on the principles of foraging theory that view foraging as optimization. This provides us with novel models of their foraging behavior and with new methods for distributed nongradient optimization. Moreover, we show that the models of both species of

Y. Liu; K. M. Passino

2002-01-01

204

The forager's dilemma: food sharing and food defense as risk-sensitive foraging options.  

PubMed

Although many variants of the hawk-dove game predict the frequency at which group foraging animals should compete aggressively, none of them can explain why a large number of group foraging animals share food clumps without any overt aggression. One reason for this shortcoming is that hawk-dove games typically consider only a single contest, while most group foraging situations involve opponents that interact repeatedly over discovered food clumps. The present iterated hawk-dove game predicts that in situations that are analogous to a prisoner's dilemma, animals should share the resources without aggression, provided that the number of simultaneously available food clumps is sufficiently large and the number of competitors is relatively small. However, given that the expected gain of an aggressive animal is more variable than the gain expected by nonaggressive individuals, the predicted effect of the number of food items in a clump-clump richness-depends on whether only the mean or both the mean and variability associated with payoffs are considered. More precisely, the deterministic game predicts that aggression should increase with clump richness, whereas the stochastic risk-sensitive game predicts that the frequency of encounters resulting in aggression should peak at intermediate clump richnesses or decrease with increasing clump richness if animals show sensitivity to the variance or coefficient of variation, respectively. PMID:14737714

Dubois, Frédérique; Giraldeau, Luc-Alain

2003-12-19

205

Seabird and Forage Fish Research in Alaska  

NSDL National Science Digital Library

The US Geological Survey (USGS)'s Alaska Biological Science Center (ABSC) conducts research in a number of areas, including this research on seabirds and forage fish in Alaska. Organized by topic, the site includes general information on marine animals and ecosystems in Alaska, specific information on ABSC seabird and fish projects (including some methods and results), and several informal 'sketches' of participating scientists. Although of particular interest to the research community, the site simultaneously serves as an excellent example of how scientists study complex ecosystems. By clicking on each "What we learned" icon, viewers may access results of specific projects and explanations of how those results tie into "the bigger picture." Further information on the Alaska Biological Science Center is provided at the ABSC homepage.

206

Experimental Study of the Dynamics of Foraging Ants  

NASA Astrophysics Data System (ADS)

We study the search paths of foraging ants in order to describe their behavior mathematically. Ants have become popular as simple agents in models of artificial life. Here, the ant is presented the problem of finding food when no food cues are present. In this experiment, individual ants (Formicinae lasius flavus) are allowed to forage on a two-dimensional textured surface in the absence of a food source. The position of the ant as a function of time is determined with a high resolution digital camera. The scaling properties of the resulting foraging paths compare favorably with those of certain types of random walk.

Walker, J. I.; Fetzner, R. P.; Baxter, G. W.

2006-03-01

207

The organization of foraging in the fire ant, Solenopsis invicta.  

PubMed

Although natural selection in ants acts most strongly at the colony, or superorganismal level, foraging patterns have rarely been studied at that level, focusing instead on the behavior of individual foragers or groups of foragers. The experiments and observations in this paper reveal in broad strokes how colonies of the fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), allocate their available labor to foraging, how they disperse that force within their territory, and how this force changes with colony size, season and worker age. Territory area is positively related to colony size and the number of foragers, more so during the spring than fall. Changes of colony size and territory area are driven by seasonal variation of sexual and worker production, which in turn drive seasonal variation of worker age-distribution. During spring sexual production, colonies shrink because worker production falls below replacement. This loss is proportional to colony size, causing forager density in the spring to be negatively related to colony and territory size. In the fall, colonies emphasize worker production, bringing colony size back up. However, because smaller colonies curtailed spring worker production less than larger ones, their fall forager populations are proportionally greater, causing them to gain territory at the expense of large colonies. Much variation of territory area remains unexplained and can probably be attributed to pressure from neighboring colonies. Boundaries between territories are characterized by "no ants' zones" mostly devoid of fire ants. The forager population can be divided into a younger group of recruitable workers that wait for scouts to activate them to help retrieve large food finds. About one-third of the recruits wait near openings in the foraging tunnels that underlie the entire territory, while two-thirds wait in the nest. Recruitment to food is initially very rapid and local from the foraging tunnels, while sustained recruitment gradually involves the recruits waiting in the nest. As recruits age, they become scouts searching for food on the surface, and die about two weeks later. Foraging tunnels decrease in cross-sectional area with distance from the nest, in keeping with the gradual bleeding off of workers to the surface with distance. Foragers lack route-faithfulness, and having been marked and released at one point within the territory, they can be recaptured at any other point a day later. The size of the territory actually occupied may be limited during dry weather, resulting in very large no-ants' zones. PMID:21529150

Tschinkel, Walter R

2011-01-01

208

The influence of body size and sex on the characteristics of harbour seal foraging trips  

Microsoft Academic Search

Most pinnipeds disperse from centralised terrestrial sites to forage at sea, but the factors that result in variation in foraging-trip characteristics remain unclear. We investigated the influence of sex and body size on the summer foraging activit y of radio-tagged harbour seals ( Phoca vitulina) from Scotland. Mean foraging-trip duration (range 17-257 h) was strongly correlated with mean foraging range

Paul M. Thompson; Ann Mackay; Dominic J. Tollit; Simon Enderby; Philip S. Hammond

1998-01-01

209

History of muskellunge management in Nebraska  

Microsoft Academic Search

Muskellunge, Esox masquinongy, were first introduced to Nebraska waters in 1958. By 1967 anglers had caught the first muskellunge from Nebraska waters.\\u000a Hybrid muskellunge, Esox masquinongy × E. lucius, culture and stocking started in 1976. Harvest regulations for muskellunge and hybrid muskellunge were first established\\u000a in 1977 with a daily bag limit of one muskellunge or hybrid muskellunge of at least 762 mm (30 inches) in

Daryl L. Bauer

210

History of muskellunge management in Nebraska  

Microsoft Academic Search

Muskellunge, Esox masquinongy, were first introduced to Nebraska waters in 1958. By 1967 anglers had caught the first muskellunge from Nebraska waters.\\u000a Hybrid muskellunge, Esox masquinongy × E. lucius, culture and stocking started in 1976. Harvest regulations for muskellunge and hybrid muskellunge were first established\\u000a in 1977 with a daily bag limit of one muskellunge or hybrid muskellunge of at least 762 mm (30 inches) in length.

Daryl L. Bauer

2007-01-01

211

Sperm Motility of Northern Pike and Chain Pickerel at Various pH Values  

Microsoft Academic Search

The activity of sperm from northern pike Esox lucius and chain pickerel Esox niger was observed at pH 3.9, 4.5, 5.4, 6.0, 6.4, 6.9, 7.4, and 7.9. The sperm of the northern pike remained motile for shorter periods of time than that of the chain pickerel (P = 0.01). Northern pike sperm was not observed swimming actively at pH values

Paul D. Duplinsky

1982-01-01

212

SITE TECHNOLOGY CAPSULE: DYNAPHORE, INC., FORAGER SPONGE TECHNOLOGY  

EPA Science Inventory

The Forager Sponge is a volume reduction technology in which heavy metal contaminants from an aqueous medium are selectively concentrated into a smaller volume for facilitated disposal. he technology treats contaminated groundwater, surface waters and porous waters by absorbing d...

213

The foraging behavior of the ant Myrmica laevinodis nyl.  

PubMed

The foraging territory is not divided among particular foragers, at least in the young, small families of M. laevinodis. The same individuals may be observed repeatedly only at the aphides over a period of several days, which may be explained by a transient memorizing of the source of attractive food. Along with the faculty of these ants to inform their nestmates of the food source, a certain continuity in care of the aphides is ensured. Various forms of behavior among particular foragers coming in contact with the trophy exceeding their strength were noted. The less time the ant hesitates before to the nest, the sooner and more efficiently it recruits helpers and the smaller is its dependence on its own odor trails when moving on the terrain. Since there exist transitory forms between diametrically opposite manifestations of such behavior, possibly the process of individual acquirement of capabilities necessary for fulfilling foraging function occurs. PMID:1007976

Dobrza?ska, J; Dobrza?ski, J

1976-01-01

214

Forage Quality in Burned and Unburned Aspen Communities.  

National Technical Information Service (NTIS)

Selected forage species were sampled during the first and second summers after autumn prescribed burning of three sites in southeastern Idaho. They were analyzed for in vitro dry matter digestibility, protein, calcium, and phosphorus. This aspen type has ...

N. V. DeByle P. J. Urness D. L. Blank

1989-01-01

215

Leucaena: New Forage and Tree Crop for the Tropics.  

National Technical Information Service (NTIS)

The report describes Leucaena leucocephala, a little-known Mexican plant with bushy and tree-type varieties that produce nutritious forage, firewood, timber, paper pulp, and organic fertilizer. Its diverse uses also include revegetating hillslopes and pro...

1977-01-01

216

Dimorphic foraging behaviors and the evolution of hominid hunting.  

PubMed

In contemporary foraging societies men typically hunt more than women. This observation has played an important role in many reconstructions of hominid evolution. The gender difference in human hunting, likely a product of both ecological and cultural factors, is mirrored by a similar sex difference among nonhuman primates. Existing explanations of such primate behavioral dimorphism are augmented by the recognition of an additional factor that may contribute to differences between males and females in the value of meat. Episodic female immunosuppression is a normal part of reproduction. Because meat is a source of pathogens, females can be expected to exhibit less constant attraction to meat. Sexual dimorphism in the attraction to meat may then contribute to dimorphic foraging specializations, a divergence that is likely augmented by the differential value of insectivory across the sexes. With the rise of cultural transmission of foraging knowledge, dimorphic foraging behaviors would have been reinforced, creating a more comprehensive gender-based division of labor. PMID:12680308

Fessler, Daniel M T

217

Specialist Osmia Bees Forage Indiscriminately Among Hybridizing Balsamorhiza Floral Hosts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Even generalist pollinators are typically taxonomic specialists during individual foraging bouts. Such floral constancy restricts pollen flow, and thereby gene flow, between otherwise inter-fertile flowering species, thus serving as an ethological mating barrier. Among incipient species, however, ...

218

Adélie penguin foraging location predicted by tidal regime switching.  

PubMed

Penguin foraging and breeding success depend on broad-scale environmental and local-scale hydrographic features of their habitat. We investigated the effect of local tidal currents on a population of Adélie penguins on Humble Is., Antarctica. We used satellite-tagged penguins, an autonomous underwater vehicle, and historical tidal records to model of penguin foraging locations over ten seasons. The bearing of tidal currents did not oscillate daily, but rather between diurnal and semidiurnal tidal regimes. Adélie penguins foraging locations changed in response to tidal regime switching, and not to daily tidal patterns. The hydrography and foraging patterns of Adélie penguins during these switching tidal regimes suggest that they are responding to changing prey availability, as they are concentrated and dispersed in nearby Palmer Deep by variable tidal forcing on weekly timescales, providing a link between local currents and the ecology of this predator. PMID:23383091

Oliver, Matthew J; Irwin, Andrew; Moline, Mark A; Fraser, William; Patterson, Donna; Schofield, Oscar; Kohut, Josh

2013-01-30

219

Quantifying rhizosphere respiration for two cool-season perennial forages  

Technology Transfer Automated Retrieval System (TEKTRAN)

Understanding the regulation of ecosystem carbon dioxide flux from forage production systems requires knowledge of component fluxes, including photosynthetic uptake and respiratory loss. Experimental separation of soil respiration into its heterotrophic (free-living soil organisms) and rhizosphere c...

220

Flexible Foraging of Ants under Unsteadily Varying Environment  

NASA Astrophysics Data System (ADS)

Using a simple model for the trail formation of ants, the relation between i) the schedule of feeding which represents the unsteady natural environment, ii) emerging patterns of trails connecting a nest with food resources, and iii) the foraging efficiency is studied. Simulations and a simple analysis show that the emergent trail pattern flexibly varies depending on the feeding schedule by which ants can make an efficient foraging according to the underlying unsteady environment.

Tao, Tomomi; Nakagawa, Hiroyuki; Yamasaki, Masato; Nishimori, Hiraku

2004-08-01

221

Foraging tactics of two guilds of web-spinning spiders  

Microsoft Academic Search

The foraging behavior of orbweaving and sheetweb weaving guilds of spiders was investigated. Orbweavers move among web-sites frequently, but sheetweb weavers do not. A simple model that examines the adaptive advantages of active foraging and sit-and-wait strategies leads to three predictions: 1) Orbweavers should have a simple decision rule for leaving web-sites, 2) Orbweavers' web-sites should have more variable payoffs

Anthony C. Janetos

1982-01-01

222

Central-place foraging by humans: transport and processing  

Microsoft Academic Search

The Darwinian approach to behavior generates models that are widely used by anthropologists and archeologists. In this paper,\\u000a I concentrate on a particular group of models based on cases in which a forager (or group of foragers) brings resources to\\u000a a location known as a central place. I examine two topics in detail: (1) the economics of transporting a load

Alasdair I. Houston

2011-01-01

223

A guide to central place effects in foraging  

Microsoft Academic Search

We develop a general patch-use model of central place foraging, which subsumes and extends several previous models. The model produces a catalog of central place effects predicting how distance from a central place influences the costs and benefits of foraging, load-size, quitting harvest rates, and giving-up densities. In the model, we separate between costs that are load-size dependent, i.e. a

Ola Olsson; Joel S. Brown; Kurt L. Helf

2008-01-01

224

Foragers of the harvester ant, Pogonomyrmex owyheei : a disposable caste?  

Microsoft Academic Search

1.Exterior workers of the harvester ant, Pogonomyrmex owyheei, were subdivided into forager, defender and refuse worker behavior roles (Fig. 2). Exterior workers comprised approximately 16% of the total colony population with interior workers comprising the remainder.2.An average of less than 10% of the total worker population foraged (Table 1). Studies of role changes comfirmed a general one-way progression from interior

Sanford D. Porter; Clive D. Jorgensen

1981-01-01

225

The forager oral tradition and the evolution of prolonged juvenility.  

PubMed

The foraging niche is characterized by the exploitation of nutrient-rich resources using complex extraction techniques that take a long time to acquire. This costly period of development is supported by intensive parental investment. Although human life history theory tends to characterize this investment in terms of food and care, ethnographic research on foraging skill transmission suggests that the flow of resources from old-to-young also includes knowledge. Given the adaptive value of information, parents may have been under selection pressure to invest knowledge - e.g., warnings, advice - in children: proactive provisioning of reliable information would have increased offspring survival rates and, hence, parental fitness. One way that foragers acquire subsistence knowledge is through symbolic communication, including narrative. Tellingly, oral traditions are characterized by an old-to-young transmission pattern, which suggests that, in forager groups, storytelling might be an important means by which adults transfer knowledge to juveniles. In particular, by providing juveniles with vicarious experience, storytelling may expand episodic memory, which is believed to be integral to the generation of possible future scenarios (i.e., planning). In support of this hypothesis, this essay reviews evidence that: mastery of foraging knowledge and skill sets takes a long time to acquire; foraging knowledge is transmitted from parent to child; the human mind contains adaptations specific to social learning; full assembly of learning mechanisms is not complete in early childhood; and forager oral traditions contain a wide range of information integral to occupation of the foraging niche. It concludes with suggestions for tests of the proposed hypothesis. PMID:21897825

Scalise Sugiyama, Michelle

2011-08-23

226

VARIATION IN FORAGING AND PARENTAL BEHAVIOR OF KING CORMORANTS  

Microsoft Academic Search

We studied sexual and individual differences in foraging and parental be- havior of King Cormorants (Phalacrocorax albiventer) during the brood-rearing period at Mac- quarie Island. King Cormorants exhibit sexual dimorphism in size, with males being 16% heavier than females. Females foraged mainly in the morning and males in the afternoon. Five females were shallow divers (1.9 to 6.8 m), and

Akiko Kato; Yutaka Watanuki; Isao Nishiumi; Maki Kuroki; Peter Shaughnessy; Yasuhiko Naito

2000-01-01

227

Foraging Ecology Predicts Learning Performance in Insectivorous Bats  

PubMed Central

Bats are unusual among mammals in showing great ecological diversity even among closely related species and are thus well suited for studies of adaptation to the ecological background. Here we investigate whether behavioral flexibility and simple- and complex-rule learning performance can be predicted by foraging ecology. We predict faster learning and higher flexibility in animals hunting in more complex, variable environments than in animals hunting in more simple, stable environments. To test this hypothesis, we studied three closely related insectivorous European bat species of the genus Myotis that belong to three different functional groups based on foraging habitats: M. capaccinii, an open water forager, M. myotis, a passive listening gleaner, and M. emarginatus, a clutter specialist. We predicted that M. capaccinii would show the least flexibility and slowest learning reflecting its relatively unstructured foraging habitat and the stereotypy of its natural foraging behavior, while the other two species would show greater flexibility and more rapid learning reflecting the complexity of their natural foraging tasks. We used a purposefully unnatural and thus species-fair crawling maze to test simple- and complex-rule learning, flexibility and re-learning performance. We found that M. capaccinii learned a simple rule as fast as the other species, but was slower in complex rule learning and was less flexible in response to changes in reward location. We found no differences in re-learning ability among species. Our results corroborate the hypothesis that animals’ cognitive skills reflect the demands of their ecological niche.

Clarin, Theresa M. A.; Ruczynski, Ireneusz; Page, Rachel A.

2013-01-01

228

Foraging ecology predicts learning performance in insectivorous bats.  

PubMed

Bats are unusual among mammals in showing great ecological diversity even among closely related species and are thus well suited for studies of adaptation to the ecological background. Here we investigate whether behavioral flexibility and simple- and complex-rule learning performance can be predicted by foraging ecology. We predict faster learning and higher flexibility in animals hunting in more complex, variable environments than in animals hunting in more simple, stable environments. To test this hypothesis, we studied three closely related insectivorous European bat species of the genus Myotis that belong to three different functional groups based on foraging habitats: M. capaccinii, an open water forager, M. myotis, a passive listening gleaner, and M. emarginatus, a clutter specialist. We predicted that M. capaccinii would show the least flexibility and slowest learning reflecting its relatively unstructured foraging habitat and the stereotypy of its natural foraging behavior, while the other two species would show greater flexibility and more rapid learning reflecting the complexity of their natural foraging tasks. We used a purposefully unnatural and thus species-fair crawling maze to test simple- and complex-rule learning, flexibility and re-learning performance. We found that M. capaccinii learned a simple rule as fast as the other species, but was slower in complex rule learning and was less flexible in response to changes in reward location. We found no differences in re-learning ability among species. Our results corroborate the hypothesis that animals' cognitive skills reflect the demands of their ecological niche. PMID:23755146

Clarin, Theresa M A; Ruczy?ski, Ireneusz; Page, Rachel A; Siemers, Björn M

2013-06-05

229

Information Foraging in Nuclear Power Plant Control Rooms  

SciTech Connect

nformation foraging theory articulates the role of the human as an 'informavore' that seeks information and follows optimal foraging strategies (i.e., the 'information scent') to find meaningful information. This paper briefly reviews the findings from information foraging theory outside the nuclear domain and then discusses the types of information foraging strategies operators employ for normal and off-normal operations in the control room. For example, operators may employ a predatory 'wolf' strategy of hunting for information in the face of a plant upset. However, during routine operations, the operators may employ a trapping 'spider' strategy of waiting for relevant indicators to appear. This delineation corresponds to information pull and push strategies, respectively. No studies have been conducted to determine explicitly the characteristics of a control room interface that is optimized for both push and pull information foraging strategies, nor has there been empirical work to validate operator performance when transitioning between push and pull strategies. This paper explores examples of control room operators as wolves vs. spiders and con- cludes by proposing a set of research questions to investigate information foraging in control room settings.

R.L. Boring

2011-09-01

230

Sex-specific foraging behaviour in a monomorphic seabird.  

PubMed Central

Sexual differences in the foraging behaviour of parents have been observed in a number of sexually sizedimorphic birds, particularly seabirds, and the usual inference has been that these sex-specific differences are mediated primarily by differences in body size. To test this explanation, we compared the foraging behaviour of parents in a monomorphic seabird species, the northern gannet Morus bassanus. Using specially designed instruments and radio telemetry we found that individuals of both sexes were consistent in the directions and durations of their foraging trips. However, there were significant differences in the foraging behaviour of males and females. Female gannets were not only more selective than males in the areas where they foraged, but they also made longer, deeper dives and spent more time on the sea surface than males. As the sexes are morphologically similar in this species, then these differences are unlikely to have been mediated by body size. Our work highlights the need to investigate sexual differences in the foraging behaviour of seabirds and other species more closely, in order to test alternative theories that do not rely on differences in body size.

Lewis, S; Benvenuti, S; Dall'Antonia, L; Griffiths, R; Money, L; Sherratt, T N; Wanless, S; Hamer, K C

2002-01-01

231

Central place foraging by beavers ( Castor canadensis ): a test of foraging predictions and the impact of selective feeding on the growth form of cottonwoods ( Populus fremontii )  

Microsoft Academic Search

Several predictions of central place foraging theory were tested. As predicted, beavers foraged more selectively at increasing distance from the central place. With increasing distance from the river's edge, beavers cut fewer branches and deleted small branches from their diet. Large branches were favored at all distances, which differs from patterns observed in previous studies of beaver foraging. This difference,

Mark A. McGinley; Thomas G. Whitham

1985-01-01

232

Use of forage inoculants with or without enzymes to improve preservation and quality of whole crop barley forage ensiled as large bales  

Microsoft Academic Search

Moshtaghi Nia, S. A. and Wittenberg, K. M. 1999. Use of forage inoculants with or without enzymes to improve preservation and quality of whole crop barley forage ensiled as large bales. Can. J. Anim. Sci. 79: 525-532. The effects of forage additives, applied to bales wrapped at either 2 or 10 h post-baling, on preservation and quality of whole barley

S. A. Moshtaghi Nia; K. M. Wittenberg

1999-01-01

233

Tandem carrying, a new foraging strategy in ants: description, function, and adaptive significance relative to other described foraging strategies  

NASA Astrophysics Data System (ADS)

An important aspect of social insect biology lies in the expression of collective foraging strategies developed to exploit food. In ants, four main types of foraging strategies are typically recognized based on the intensity of recruitment and the importance of chemical communication. Here, we describe a new type of foraging strategy, "tandem carrying", which is also one of the most simple recruitment strategies, observed in the Ponerinae species Pachycondyla chinensis. Within this strategy, workers are directly carried individually and then released on the food resource by a successful scout. We demonstrate that this recruitment is context dependent and based on the type of food discovered and can be quickly adjusted as food quality changes. We did not detect trail marking by tandem-carrying workers. We conclude by discussing the importance of tandem carrying in an evolutionary context relative to other modes of recruitment in foraging and nest emigration.

Guénard, Benoit; Silverman, Jules

2011-08-01

234

Central place foraging by breeding Cook’s petrel Pterodroma cookii : foraging duration reflects range, diet and chick meal mass  

Microsoft Academic Search

Pelagic seabirds are central place foragers during breeding and variation in foraging trip duration and range reflect differences\\u000a in diet and chick provisioning, through the exploitation of divergent habitats of varying productivity. We tested whether\\u000a these relationships hold in small procellarriids by equipping chick-rearing Cook’s petrel Pterodroma cookii (200 g) with geolocation-immersion loggers, conducting isotope analysis of blood and measuring chick

M. J. Rayner; B. W. Hartill; M. E. Hauber; R. A. Phillips

2010-01-01

235

Managing manure nutrients through multi-crop forage production.  

PubMed

Concentrated sources of dairy manure represent significant water pollution potential. The southern United States may be more vulnerable to water quality problems than some other regions because of climate, typical farm size, and cropping practices. Dairy manure can be an effective source of plant nutrients and large quantities of nutrients can be recycled through forage production, especially when multi-cropping systems are utilized. Linking forage production with manure utilization is an environmentally sound approach for addressing both of these problems. Review of two triple-crop systems revealed greater N and P recoveries for a corn silage-bermudagrass hay-rye haylage system, whereas forage yields and quality were greater for a corn silage-corn silage-rye haylage system, when manure was applied at rates to supply N. Nutrient uptake was lower than application during the autumn-winter period, and bermudagrass utilized more of the remaining excess than a second crop of corn silage. Economic comparison of these systems suggests that the added value of the two corn silage crop system was not enough to off-set its increased production cost. Therefore, the system that included bermudagrass demonstrated both environmental and economic advantages. Review of the N and P uptake and calculated crop value of various single, double, and triple crop forage systems indicated that the per hectare economic value as well as the N and P uptakes tended to follow DM yields, and grasses tended to out-perform broadleaf forages. Taken across all systems, systems that included bermudagrass tended to have some of the highest economic values and uptakes of N and P. Manure applied at rates to supply N results in application of excess P, and production will not supply adequate quantities of forage to meet the herd's needs. Systems that lower manure application and supply supplemental N to produce all necessary forage under manure application will likely be less economically attractive due to additional costs of moving manure further and, applying it to greater land areas, but will be environmentally necessary in most cases. Intensive forage systems can produce acceptable to high quality forage, protect the environment, and be economically attractive. The optimal manure-forage system will depend on the farm characteristics and specific local conditions. Buffers and nutrient sinks can protect streams and water bodies from migrating nutrients and should be included as a part of crop production systems. PMID:12836962

Newton, G L; Bernard, J K; Hubbard, R K; Allison, J R; Lowrance, R R; Gascho, G J; Gates, R N; Vellidis, G

2003-06-01

236

Bilateral Comparison in Chemosensory-Mediated Foraging  

NASA Astrophysics Data System (ADS)

Motivation is drawn from the need to determine the sensory cues that animals such as blue crabs and lobsters use to track chemical odor plumes to locate food or mates. Major steps forward with this difficult problem can only be achieved through an appreciation of the spatial and temporal variation of concentration fields and the information content available to a forager in the plume. Here we discuss the usefulness of bilateral comparison to an animal tracking a turbulent plume. Instantaneous concentration fields of a chemical plume diffusing in a fully-developed turbulent open channel flow are measured using planar laser-induced fluorescence (PLIF). The plume is released iso-kinetically 25 mm above the smooth bed (z+ = 90), thus transport is mainly due to advection and ambient turbulence. A spatial correlation function in the spanwise direction is a dramatic indicator of the relative position of the centerline and distance from the source. The relative direction of the plume centerline can be estimated from an instantaneous bilateral comparison provided the sensors are separated by a distance that is relatively large compared to the spanwise integral length scale based on the spatial correlation function.

Webster, D. R.; Rahman, S.; Dasi, L. P.

2000-11-01

237

Eye structure and amphibious foraging in albatrosses  

PubMed Central

Anterior eye structure and retinal visual fields were determined in grey-headed and black-browed albatrosses, Diomedea melanophris and D. chrysostoma (Procellariiformes, Diomedeidae), using keratometry and an ophthalmoscopic reflex technique. Results for the two species were very similar and indicate that the eyes are of an amphibious optical design suggesting that albatross vision is well suited to the visual pursuit of active prey both on and below the ocean surface. The corneas are relatively flat (radius ca. 14.5 mm) and hence of low absolute refractive power (ca. 23 dioptres). In air the binocular fields are relatively long (vertical extent ca. 70 degrees) and narrow (maximum width in the plane of the optic axes 26–32 degrees), a topography found in a range of bird species that employ visual guidance of bill position when foraging. The cyclopean fields measure approximately 270 degrees in the horizontal plane, but there is a 60 degrees blind sector above the head owing to the positioning of the eyes below the protruding supraorbital ridges. Upon immersion the monocular fields decrease in width such that the binocular fields are abolished. Anterior eye structure, and visual field topography in both air and water, show marked similarity with those of the Humboldt penguin.

Martin, G. R.

1998-01-01

238

Simultaneous brightness contrast of foraging Papilio butterflies  

PubMed Central

This study focuses on the sense of brightness in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive brightness in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn brightness and darkness of targets independent of colour, and that they have the so-called simultaneous brightness contrast.

Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro

2012-01-01

239

Insect prey foraging strategies in Callicebus oenanthe in northern Peru.  

PubMed

Titi monkeys (genus Callicebus) are small-bodied platyrrhines that supplement their predominantly frugivorous diet with variable amounts of leaves, seeds, and/or arthropod prey. Notable interspecific variation in the amount of insect prey in the diet has been observed in Callicebus, ranging from 0% to 20%. In this study, I investigate the degree and type of prey foraging in a little-known species, Callicebus oenanthe inhabiting a fragmented, secondary forest on the foothills of the Andes in northern Peru. I present data on prey type, prey search and capture techniques, substrate/vegetation use, foraging height, prey capture efficiency, and seasonal variation of insect prey foraging in one group of C. oenanthe observed from January to August 2005. Insect prey accounted for 22% of the diet, the highest amount reported for any Callicebus species to date, and insects from at least six different orders were included. C. oenanthe was mainly an investigative forager of hidden prey, manipulating easy-to-open substrates such as rolled up leaves, and hunted ant swarms and larger insects opportunistically. Insect foraging was predominant during the dry season (26%) and decreased during the wet season (13%). The study group foraged mostly in the understory (2-6 m) within vine-laden shrubs and trees, which may conform to an anti-predator strategy of crypticity. Overall the group had an 83% insect capture success rate. These data suggest that insect prey is an important part of the diet of C. oenanthe and may be especially notable during periods of resource scarcity. This study adds to the knowledge concerning insect prey foraging in Callicebus, which can have an important role in defining ecological strategies in the selection of secondary protein food resources within a given ecosystem. PMID:22311736

Deluycker, Anneke M

2012-02-06

240

Delay reduction and optimal foraging: variable-ratio search in a foraging analogue.  

PubMed Central

The present study investigated conditions under which the conditioned reinforcement principles of delay-reduction theory and views based on simple maximization of reinforcement rate make ordinally opposing predictions with respect to foraging-related choice behavior. The use of variable-ratio schedules in the choice phase also represents an extension of delay-reduction theory to schedules that may better mimic the effort involved in searching. Pigeons responded on modified concurrent-chains schedules in which equal variable-ratio schedules led to unequal variable-interval outcomes and unequal reinforcer amounts. All 4 subjects completed a minimum of two replications of conditions for which the predictions of delay-reduction theory and a simple rate-maximizing theory were opposed. Results were consistent with delay reduction's ordinal predictions in 11 of 11 replications of the divergent predictions favoring the smaller, more immediate alternative. The predictions of rate maximization were upheld only when they were consistent with those of delay reduction. Results are discussed in terms of conditioned reinforcement, sensitivity to reductions in delay to food, and possible rules of thumb that may be useful in characterizing foraging.

Williams, W A; Fantino, E

1994-01-01

241

Trail geometry gives polarity to ant foraging networks.  

PubMed

Pheromone trails are used by many ants to guide foragers between nest and food. But how does a forager that has become displaced from a trail know which way to go on rejoining the trail? A laden forager, for example, should walk towards the nest. Polarized trails would enable ants to choose the appropriate direction, thereby saving time and reducing predation risk. However, previous research has found no evidence that ants can detect polarity from the pheromone trail alone. Pharaoh's ants (Monomorium pharaonis) produce elaborate trail networks throughout their foraging environment. Here we show that by using information from the geometry of trail bifurcations within this network, foragers joining a trail can adaptively reorientate themselves if they initially walk in the wrong direction. The frequency of correct reorientations is maximized when the trail bifurcation angle is approximately 60 degrees, as found in natural networks. These are the first data to demonstrate how ant trails can themselves provide polarity information. They also demonstrate previously unsuspected sophistication in the organization and information content of networks in insect societies. PMID:15602563

Jackson, Duncan E; Holcombe, Mike; Ratnieks, Francis L W

2004-12-16

242

Corticosterone predicts foraging behavior and parental care in macaroni penguins.  

PubMed

Corticosterone has received considerable attention as the principal hormonal mediator of allostasis or physiological stress in wild animals. More recently, it has also been implicated in the regulation of parental care in breeding birds, particularly with respect to individual variation in foraging behavior and provisioning effort. There is also evidence that prolactin can work either inversely or additively with corticosterone to achieve this. Here we test the hypothesis that endogenous corticosterone plays a key physiological role in the control of foraging behavior and parental care, using a combination of exogenous corticosterone treatment, time-depth telemetry, and physiological sampling of female macaroni penguins (Eudyptes chrysolophus) during the brood-guard period of chick rearing, while simultaneously monitoring patterns of prolactin secretion. Plasma corticosterone levels were significantly higher in females given exogenous implants relative to those receiving sham implants. Increased corticosterone levels were associated with significantly higher levels of foraging and diving activity and greater mass gain in implanted females. Elevated plasma corticosterone was also associated with an apparent fitness benefit in the form of increased chick mass. Plasma prolactin levels did not correlate with corticosterone levels at any time, nor was prolactin correlated with any measure of foraging behavior or parental care. Our results provide support for the corticosterone-adaptation hypothesis, which predicts that higher corticosterone levels support increased foraging activity and parental effort. PMID:22673661

Crossin, Glenn T; Trathan, Phil N; Phillips, Richard A; Gorman, Kristen B; Dawson, Alistair; Sakamoto, Kentaro Q; Williams, Tony D

2012-05-24

243

A mathematical model of foraging in a dynamic environment by trail-laying Argentine ants.  

PubMed

Ants live in dynamically changing environments, where food sources become depleted and alternative sources appear. Yet most mathematical models of ant foraging assume that the ants' foraging environment is static. Here we describe a mathematical model of ant foraging in a dynamic environment. Our model attempts to explain recent empirical data on dynamic foraging in the Argentine ant Linepithema humile (Mayr). The ants are able to find the shortest path in a Towers of Hanoi maze, a complex network containing 32,768 alternative paths, even when the maze is altered dynamically. We modify existing models developed to explain ant foraging in static environments, to elucidate what possible mechanisms allow the ants to quickly adapt to changes in their foraging environment. Our results suggest that navigation of individual ants based on a combination of one pheromone deposited during foraging and directional information enables the ants to adapt their foraging trails and recreates the experimental results. PMID:22575583

Ramsch, Kai; Reid, Chris R; Beekman, Madeleine; Middendorf, Martin

2012-04-10

244

Optimal foraging for specific nutrients in predatory beetles.  

PubMed

Evolutionary theory predicts that animals should forage to maximize their fitness, which in predators is traditionally assumed equivalent to maximizing energy intake rather than balancing the intake of specific nutrients. We restricted female predatory ground beetles (Anchomenus dorsalis) to one of a range of diets varying in lipid and protein content, and showed that total egg production peaked at a target intake of both nutrients. Other beetles given a choice to feed from two diets differing only in protein and lipid composition selectively ingested nutrient combinations at this target intake. When restricted to nutritionally imbalanced diets, beetles balanced the over- and under-ingestion of lipid and protein around a nutrient composition that maximized egg production under those constrained circumstances. Selective foraging for specific nutrients in this predator thus maximizes its reproductive performance. Our findings have implications for predator foraging behaviour and in the structuring of ecological communities. PMID:22237910

Jensen, Kim; Mayntz, David; Toft, Søren; Clissold, Fiona J; Hunt, John; Raubenheimer, David; Simpson, Stephen J

2012-01-11

245

Central-place seed foraging and vegetation patterns.  

PubMed

We investigate how central-place seed foragers with a nest in the proximity of one or more seed sources determine the formation of different vegetation patterns. In particular, we discuss the ecological conditions that lead to the formation of hump-shaped (Janzen-Connell) patterns in a two-dimensional landscape. Our analysis shows that central-place predation can generate Janzen-Connell patterns even if predators' movement strategies are exclusively based on resource abundance, both in the single-plant/single-nest case and in a forest with several seed sources. We also show that social foraging may either promote or work against the formation of Janzen-Connell patterns, depending upon the way foragers take advantage of social interactions. PMID:19682475

Mari, Lorenzo; Gatto, Marino; Casagrandi, Renato

2009-08-12

246

Context dependence in foraging behaviour of Achillea millefolium.  

PubMed

Context-dependent foraging behaviour is acknowledged and well documented for a diversity of animals and conditions. The contextual determinants of plant foraging behaviour, however, are poorly understood. Plant roots encounter patchy distributions of nutrients and soil fungi. Both of these features affect root form and function, but how they interact to affect foraging behaviour is unknown. We extend the use of the marginal value theorem to make predictions about the foraging behaviour of roots, and test our predictions by manipulating soil resource distribution and inoculation by soil fungi. We measured plant movement as both distance roots travelled and time taken to grow through nutrient patches of varied quality. To do this, we grew Achillea millefolium in the centers of modified pots with a high-nutrient patch and a low-nutrient patch on either side of the plant (heterogeneous) or patch-free conditions (homogeneous). Fungal inoculation, but not resource distribution, altered the time it took roots to reach nutrient patches. When in nutrient patches, root growth decreased relative to homogeneous soils. However, this change in foraging behaviour was not contingent upon patch quality or fungal inoculation. Root system breadth was larger in homogeneous than in heterogeneous soils, until measures were influenced by pot edges. Overall, we find that root foraging behaviour is modified by resource heterogeneity but not fungal inoculation. We find support for predictions of the marginal value theorem that organisms travel faster through low-quality than through high-quality environments, with the caveat that roots respond to nutrient patches per se rather than the quality of those patches. PMID:22622873

Karst, Justine D; Belter, Pamela R; Bennett, Jonathan A; Cahill, James F

2012-05-24

247

Contrafreeloading in grizzly bears: implications for captive foraging enrichment.  

PubMed

Although traditional feeding regimens for captive animals were focused on meeting physiological needs to assure good health, more recently emphasis has also been placed on non-nutritive aspects of feeding. The provision of foraging materials to diversify feeding behavior is a common practice in zoos but selective consumption of foraging enrichment items over more balanced "chow" diets could lead to nutrient imbalance. One alternative is to provide balanced diets in a contrafreeloading paradigm. Contrafreeloading occurs when animals choose resources that require effort to exploit when identical resources are freely available. To investigate contrafreeloading and its potential as a theoretical foundation for foraging enrichment, we conducted two experiments with captive grizzly bears (Ursus arctos horribilis). In Experiment 1, bears were presented with five foraging choices simultaneously: apples, apples in ice, salmon, salmon in ice, and plain ice under two levels of food restriction. Two measures of contrafreeloading were considered: weight of earned food consumed and time spent working for earned food. More free than earned food was eaten, with only two bears consuming food extracted from ice, but all bears spent more time manipulating ice containing salmon or apples than plain ice regardless of level of food restriction. In Experiment 2, food-restricted bears were presented with three foraging choices simultaneously: apples, apples inside a box, and an empty box. Although they ate more free than earned food, five bears consumed food from boxes and all spent more time manipulating boxes containing apples than empty boxes. Our findings support the provision of contrafreeloading opportunities as a foraging enrichment strategy for captive wildlife. PMID:19816856

McGowan, Ragen T S; Robbins, Charles T; Alldredge, J Richard; Newberry, Ruth C

248

Potential application of the bumblebee foraging recruitment pheromone for commercial greenhouse pollination  

Microsoft Academic Search

Commercial bumblebee colonies are important crop pollinators. Here we assess whether application of artificial foraging recruitment\\u000a pheromone can increase foraging activity in Bombus terrestris colonies on a relevant timescale for commercial pollination. We measured bee traffic from the nest to a foraging arena, which\\u000a is correlated with foraging activity under natural recruitment conditions. During continuous pheromone exposure bee traffic\\u000a increased

Mathieu Molet; Lars Chittka; Nigel E. Raine

2009-01-01

249

Fusarium mycotoxins in forage maize — occurrence, risk assessment, minimization  

Microsoft Academic Search

The deoxynivalenol contents of forage maize in this study ranged between 0.22 and 12.9 mg\\/kg DM, but seldom exceeded critical\\u000a concentrations suggested for ruminant diets. Zearalenone was found in considerably lower concentrations than DON and rarely\\u000a reached critical levels. Therefore risk to the health and performance of ruminants is regarded as low.\\u000a \\u000a \\u000a Fusarium toxin occurrence in forage maize can be

E. Oldenburg; F. Höppner

2003-01-01

250

Breeding Better Forages to Help Feed Man and Preserve and Enhance the Environment  

ERIC Educational Resources Information Center

|Discusses the importance of forages in agriculture, and expresses the need for the same high level of technology that is used in the production of corn, wheat, and rice to be applied to forage production. Describes promising forage species, breeding objectives, and breeding procedures used in research. (JR)|

Burton, Glenn W.

1973-01-01

251

Breeding Better Forages to Help Feed Man and Preserve and Enhance the Environment  

ERIC Educational Resources Information Center

Discusses the importance of forages in agriculture, and expresses the need for the same high level of technology that is used in the production of corn, wheat, and rice to be applied to forage production. Describes promising forage species, breeding objectives, and breeding procedures used in research. (JR)

Burton, Glenn W.

1973-01-01

252

Seeding Herbs to Enhance Cervid Forage and Reforestation in Pacific Northwest Conifer Forests  

Microsoft Academic Search

Forage seeding, seeding grasses and legumes in conifer plantations, has been touted as a method of simultaneously improving elk (Cervus elaphus) and black-tailed deer (Odocoileus hemionus columbianus) nutrition and forest regeneration. When suited to local physiographical and biological conditions forage seeding may (1) increase the nutritional quality and biomass of forage preferred by cervids and (2) reduce the establishment of

James M. Becker; Timothy Quinn; Kenneth J. Raedeke

1996-01-01

253

Diel variation of intertidal foraging by Cancer productus L. in British Columbia  

Microsoft Academic Search

Scuba was used at high tide to observe the foraging activity of Cancer Productus L. on the rocky shores of British Columbia. Intertidal foraging occurred most frequently on shores protected from wave action. In the latter areas crabs displayed marked diel shifts in density, size, and sex ratio. Crabs did not forage intertidally at low water, but increased from 0·015

C. Robles; D. A. Sweetnam; D. Dittman

1989-01-01

254

FORAGING STRATEGY OF WANDERING ALBATROSSES THROUGH THE BREEDING SEASON: A STUDY USING SATELLITE TELEMETRY  

Microsoft Academic Search

Satellite telemetry of Wandering Albatrosses (Diomedea exulans) breeding on the Crozet Islands, southwestern Indian Ocean, revealed two distinct foraging strategies during successive stages of the breeding season: systematic foraging over extensive distances; and use of specific areas close to the colony. During early incubation, Wandering Albatrosses foraged over pelagic waters at an average range of 1,284 kin. The length of

HENRI WEIMERSKIRCH; MARC SALAMOLARD; FRANCOIS SARRAZIN; PIERRE JOUVENTIN

1993-01-01

255

Multiple central place foraging by spider monkeys: travel consequences of using many sleeping sites  

Microsoft Academic Search

Central place foraging models assume that animals return to a single central place such as a nest, burrow, or sleeping site. Many animals, however choose between one of a limited number of central places. Such animals can be considered Multiple Central Place Foragers (MCPF), and such a strategy could reduce overall travel costs, if the forager selected a sleeping site

C. A. Chapman; L. J. Chapman; R. L. McLaughlin

1989-01-01

256

Foraging innovation is inversely related to competitive ability in male but not in female guppies  

Microsoft Academic Search

Foraging success is likely to affect hunger level and motivation to locate and exploit novel food sources in animals. We explored the relationship between scramble competition for limited food and foraging innovation in the guppy (Poecilia reticulata), predicting that poor competitors would be more likely to innovate when presented with novel foraging tasks. Among males, we found that latency to

Kevin N. Laland; Simon M. Reader

1999-01-01

257

Parasitic Varroa destructor mites influence flight duration and homing ability of infested Apis mellifera foragers  

Microsoft Academic Search

This study confirmed that infestation by Varroa destructor is lower in foragers returning to the colony than in those leaving the colony and explored causes of mite loss. Video recordings of bees at the flight entrance revealed that some mites may get lost from foragers but also showed that infested bees stay outside the colony longer. Returning tests of foragers

Jasna Kralj; Stefan Fuchs

2006-01-01

258

Forage species availability, food preference and grazing behaviour of goats in southeastern Nigeria  

Microsoft Academic Search

The grazing behaviour of three goat ecotypes, Red Sokoto (RS), West African dwarf (WAD) and their crossbreeds (CB), reared in the same environment were monitored for a period of 18 weeks at Abakaliki, Nigeria. A general inventory of forage species available and the key forage species preferred by the goats were also determined. Twenty-six forage species including 13 grasses, five

B. I Odo; F. U Omeje; J. N Okwor

2001-01-01

259

Foraging and provisioning in Antarctic fur seals: interannual variability in time-energy budgets  

Microsoft Academic Search

This study examined three competing hypotheses to explain how lactating Antarctic fur seals (Arctocephalus gazella) respond to changes in the level of resource availability. Antarctic fur seals have episodic bouts of suckling (1-3 days), alternating with foraging trips (3-10 days). Foraging time budgets varied significantly (p , .001) among 8 consecutive years at Bird Island, South Georgia. Foraging trip duration

I. L. Boyd

1999-01-01

260

Case Study: Nutrient values for spring and summer annual forages in a single cut harvest  

Technology Transfer Automated Retrieval System (TEKTRAN)

Annual forages were grown in the Central High Plains of the USA in both irrigated and dryland trials and the harvested forage was analyzed for forage composition and energy concentration. Three spring cereal crops (oats, barley, and triticale), three legumes (peas, soybeans, and vetch) and five sum...

261

Foraging and spatiotemporal territories in the honey ant Myrmecocystus mimicus wheeler (Hymenoptera: Formicidae)  

Microsoft Academic Search

The honey ant Myrmecocystus mimicus is a scavenger, forages extensively on termites, collects floral nectar, and tends homoptera. Individual foragers of M. mimicus usually disperse in all directions when leaving the nest, but there are also groups of foragers that tend to swarm out of the nest primarily in one direction. Such massive departues are usually at irregular intervals, which

Bert Hölldobler

1981-01-01

262

Colony state and regulation of pollen foraging in the honey bee, Apis mellifera L  

Microsoft Academic Search

To place social insect foraging behavior within an evolutionary context, it is necessary to establish relationships between individual foraging decisions and parameters influencing colony fitness. To address this problem, we examined interactions between individual foraging behavior and pollen storage levels in the honey bee, Apis mellifera L. Colonies responded to low pollen storage conditions by increasing pollen intake rates 54%

Jennifer H. Fewell; Mark L. Winston

1992-01-01

263

Effects of energy requirements and worker mortality on colony growth and foraging in the honey bee  

Microsoft Academic Search

A model of colony growth and foraging in the honey bee (Apis mellifera L.) is presented. It is assumed that summer workers choose a foraging strategy that maximizes colony population by the end of the season subject to the constraint that enough nectar has been stored to sustain the adult population overwinter. The optimal foraging strategy is derived with respect

Guy Beauchamp

1992-01-01

264

LINKING MOVEMENT, DIVING, AND HABITAT TO FORAGING SUCCESS IN A LARGE MARINE PREDATOR  

Microsoft Academic Search

Establishing where and when predators forage is essential to understanding trophic interactions, yet foraging behavior remains poorly understood in large marine carnivores. We investigated the factors leading to foraging success in gray seals (Halichoerus grypus) in the Northwest Atlantic in the first study to use simultaneous deployments of satellite transmitters, time depth recorders, and stomach-temperature loggers on a free- ranging

Deborah Austin; W. Don Bowen; Jim I. McMillan; Sara J. Iverson

2006-01-01

265

Stockpiled Annual Ryegrass for Winter Forage in the Lower Midwestern USA  

Microsoft Academic Search

lower Midwest, are interested in stockpiling annual ryegrass (Lolium multiflorum Lam.) as a source of high-quality winter forage. Almost creates an uneven forage supply and an intermittent no information exists about stockpiling annual ryegrass in this region. failure of the pasture system to meet livestock require- Our objective was to determine the yield and forage quality of stock- ments (Fales

R. L. Kallenbach; G. J. Bishop-Hurley; M. D. Massie; M. S. Kerley; C. A. Roberts

2003-01-01

266

Foraging behaviour and echolocation in the rufous horseshoe bat ( Rhinolophus rouxi ) of Sri Lanka  

Microsoft Academic Search

In October 1984 foraging areas and foraging behaviour of the rufous horseshoe bat, Rhinolophus rouxi, were studied around a nursery colony on the hill slopes of Sri Lanka. The bats only foraged in dense forest and were not found in open woodlands (Fig. 1). This strongly supports the hypothesis that detection of fluttering prey is by pure tone echolocation within

G. Neuweiler; W. Metzner; U. Heilmann; R. Riibsamen; M. Eckrich; H. H. Costa

1987-01-01

267

Effect of Feeding Experience on Growth, Vulnerability to Predation, and Survival of Esocids  

Microsoft Academic Search

We evaluated direct and indirect effects of feeding experience on growth, food consumption, susceptibility to predation, and survival of esocids. We conducted five experimental stockings of equal numbers and similar sizes (200 mm) of experienced (minnow-fed) and naive (pellet-fed) muskellunge Esox masquinongy (two stockings) and tiger muskellunge (muskellunge × northern pike E. lucius ; three stockings) in reservoirs. Feeding experience

Thomas A. Szendrey; David H. Wahl

1995-01-01

268

Diet and Growth of Northern Pike in the Absence of Prey Fishes: Initial Consequences for Persisting in Disturbance-Prone Lakes  

Microsoft Academic Search

The northern pike Esox lucius is a renowned piscivore, but will prey opportunistically on invertebrates (e.g., in small lakes of boreal Alberta, where winterkill can unexpectedly reduce or eliminate prey fishes). We emulated such a disturbance by stocking a fishless lake with northern pike and then monitored their diet and growth over two summers. Stomach content analysis revealed that stocked

Paul A. Venturelli; William M. Tonn

2006-01-01

269

Simplified Method Based on Bioenergetics Modeling to Estimate Food Consumption by Largemouth Bass and Northern Pike  

Microsoft Academic Search

I used results derived from a bioenergetics model to develop a simplified method of estimating food consumption by largemouth bass Micropterus salmoides and northern pike Esox lucius. Growth data for each of three populations of each species from lakes covering a wide latitudinal portion of their ranges were used together with temperature data to estimate cumulative consumption rates with the

Robert F. Carline

1987-01-01

270

Interactions between Walleyes and Four Fish Species with Implications for Walleye Stocking  

Microsoft Academic Search

We used a number of different data sets and four criteria to evaluate evidence of competition and predation between walleye Sander vitreus and northern pike Esox lucius, muskellunge E. masquinongy, smallmouth bass Micropterus dolomieu, and largemouth bass M. salmoides in northern Wisconsin lakes. The four criteria were as follows: (1) indices of population abundance were inversely related, (2) two species

Andrew H. Fayram; Michael J. Hansen; Timothy J. Ehlinger

2005-01-01

271

Relationship between Mercury Concentration and Growth Rates for Walleyes, Northern Pike, and Lake Trout from Quebec Lakes  

Microsoft Academic Search

The relationship between mercury (Hg) concentrations in fish muscle and fish growth rates was assessed for 54 walleye Sander vitreus, 52 northern pike Esox lucius, and 35 lake trout Salvelinus namaycush populations throughout the Province of Quebec, Canada. We used the von Bertalanffy growth model to estimate the ages of fish specimens for a given length, and Hg concentrations in

Mélyssa Lavigne; Marc Lucotte; Serge Paquet

2010-01-01

272

Comparison of mercury and methylmercury in northern pike and Arctic grayling from western Alaska rivers  

Microsoft Academic Search

In western Alaska, mercury (Hg) could be a potential health risk to people whose diet is primarily fish-based. In 2000, total Hg (THg) and methylmercury (MeHg) were examined in northern pike (Esox lucius) and Arctic grayling (Thymallus arcticus) from two watersheds in western Alaska, the Yukon and Kuskokwim rivers. Whitefish (Coregonus sp.) were also examined from the Kuskokwim River. Pike

Stephen C. Jewett; Xiaoming Zhang; A. Sathy Naidu; John J. Kelley; Doug Dasher; Lawrence K. Duffy

2003-01-01

273

Evaluation of Nonlethal Methods for the Analysis of Mercury in Fish Tissue  

Microsoft Academic Search

Thousands of fish are sacrificed each year to determine potential human exposure to mercury (Hg) from fish consumption. In this paper, we use lake whitefish Coregonus clupeaformis and northern pike Esox lucius to demonstrate that accurate and reliable measures of fish muscle Hg concentrations can be determined from small samples (<100 mg) harvested with biopsy tools. Reliability of results primarily

R. F. Baker; P. J. Blanchfield; M. J. Paterson; R. J. Flett; L. Wesson

2004-01-01

274

Response of the residential piscivorous fish community to introduction of a new predator type in a mesotrophic lake  

Microsoft Academic Search

Although the effects of introduced predators on prey populations in aquatic ecosystems have been studied frequently, less is known about the interactions between predators. We performed a whole-lake experiment by stocking a non-native top predator (pikeperch (Sander lucioperca)) to two residential piscivores (Eurasian perch (Perca fluviatilis) and northern pike (Esox lucius)). By analyzing spatial distribution, diet composition, growth, and consump-

Torsten Schulze; Ulrich Baade; Hendrik Dörner; Reiner Eckmann; Susanne S. Haertel-Borer; Franz Hölker; Thomas Mehner

2006-01-01

275

Comparison of dietary mercury exposure in two sympatric top predator fishes, largemouth bass and northern pike: a bioenergetics modeling approach  

Microsoft Academic Search

Physical and ecological factors, including lake temperature, fish physiology, and diet, influence methylmercury (MeHg) exposure in fish. We employed bioenergetics modeling to compare dietary MeHg exposure in sympatric top predators, largemouth bass (Micropterus salmoides) and northern pike (Esox lucius). We compared simulations using field data to hypothetical simulations with (1) ± 25% change in mean daily lake temperature for juvenile

Nicole K. MacRury; Brian D. S. Graeb; Brett M. Johnson; William H. Clements

2002-01-01

276

Development of fish mercury concentrations in Finnish reservoirs from 1979 to 1994  

Microsoft Academic Search

Mercury (Hg) concentrations in burbot (Lota lota), perch (Perca fluviatilis), northern pike (Esox lucius), roach (Rutilus rutilus), whitefish (Coregonus lavaretus) and peled (C. peled) were monitored in 18 reservoirs situated in western and northern Finland over a period of 16 years (1979–1994). The reservoirs were impounded from 1964 to 1980. The surface areas ranged between 1 and 417 km2. Data

P Porvari

1998-01-01

277

Walleye and Northern Pike:: Boost or Bane to Northwest Fisheries?  

Microsoft Academic Search

Introductions of nonnative walleye (Stizostedion vitreum) and northern pike (Esox lucius) have created popular recreational fisheries in many Northwestern waters. Rising demand for expanded angling opportunities for these species, especially walleye, has been met with growing concern about long- term risks associated with the introduction of a top predator. Proposed introductions are often con- troversial because of potential prey depletions,

Thomas E. McMahon; David H. Bennett

1996-01-01

278

Utility of Synthetic Structures for Concentrating Adult Northern Pike and Largemouth Bass  

Microsoft Academic Search

Five synthetic structure designs were compared to determine their relative value as management tools to improve sport fishing in two 25-ha warmwater impoundments on the Rocky Mountain Arsenal, near Denver, Colorado. Sonic telemetry and systematic angling were used to evaluate attraction of adult northern pike Esox lucius and largemouth bass Micropterus salmoides to artificial structures popularized by Arizona Game and

Kevin B. Rogers; Eric P. Bergersen

1999-01-01

279

Evaluation of the toxicity and efficacy of hydrogen peroxide treatments on eggs of warm- and coolwater fishes  

Microsoft Academic Search

The use of hydrogen peroxide in aquaculture is growing and there is a need to develop fundamental guidelines to effectively treat diseased fish. The safety (toxicity) of hydrogen peroxide treatments was determined on eggs of representative warm- and coolwater fish species. Eggs of northern pike (Esox lucius), walleye (Stizostedion vitreum), yellow perch (Perca flavescens), white sucker (Catostomus commersoni), lake sturgeon

Jeff J Rach; Mark P Gaikowski; George E Howe; Theresa M Schreier

1998-01-01

280

SPATIAL DISTRIBUTION AND TEMPERATURE SELECTION OF FISH NEAR THE THERMAL OUTFALL OF A POWER PLANT DURING FALL, WINTER, AND SPRING  

EPA Science Inventory

The movement patterns of 4 fish species: yellow perch (Perca flavescens), northern pike (Esox lucius), largemouth bass (Micropterus salmoides) and walleye (Stizostedion vitreum) were monitored by radio telemetry near the thermal discharge of a power plant (delta T 15C nominal). F...

281

Qualitative indices of edible and inedible products obtained from fish in the lower Yenisei River basin  

Microsoft Academic Search

The results of biochemical investigations of samples of products obtained from burbot (Lota lota L.), perch (Perca fluviatilis L.), and pike (Esox lucius L.) inhabiting the lower reaches of the Yenisei River basin are given. Biologically active substances—macro- and microelements,\\u000a fatty acids, amino acids, and vitamins—are analyzed.

A. A. Gnedov; A. A. Kaizer

2010-01-01

282

Light Trap Sampling of Juvenile Northern Pike in Wetlands Affected by Water Level Regulation1  

Microsoft Academic Search

New approaches are needed for sampling northern pike Esox lucius in the complex habitats they use as nursery areas. We examined spatial and temporal variation in light trap catches of northern pike in potential pike nursery areas affected by water level regulation in Rainy and Na- makan Reservoirs. Light trap catches varied greatly among eight sampling locations and between years

Rodney B. Pierce; Larry W. Kallemeyn; Philip J. Talmage

283

The Diel Activity of Crucian Carp, Carassius Carassius, in Relation to Chemical Cues from Predators  

Microsoft Academic Search

Chemical cues from piscivorous fish and prey alarm substances often cause rapid fright responses in prey. However little is known of how piscivore-related chemical cues affect prey behaviour over periods longer than a few hours. Here we have investigated how chemical cues from piscivorous northern pike, Esox lucius, affect habitat choice and diel activity of crucian carp, Carassius carassius, over

Lars B. Pettersson; Kent Andersson; Kristian Nilsson

2001-01-01

284

Localized defecation by pike: a response to labelling by cyprinid alarm pheromone?  

Microsoft Academic Search

Fathead minnows (Pimephales promelas) that have never encountered a predatory pike (Esox lucius), are able to detect conspecific alarm pheromone in a pike's diet if the pike has recently consumed minnows. It remains unclear how this minnow alarm pheromone is secreted by pike and if a pike is able to avoid being labelled as a potential predator by localizing these

Grant E. Brown; Douglas P. Chivers; R. Jan F. Smith

1995-01-01

285

The role of olfaction in chemosensory-based predator recognition in the fathead minnow, Pimephales promelas  

Microsoft Academic Search

Solitary fathead minnows (Pimephales promelas) were rendered anosmic and exposed to chemical stimuli from a predatory northern pike (Esox lucius) to determine the role of olfaction in the minnow's ability to recognize predators on the basis of chemical stimuli. Anosmic fish did not respond to the pike stimuli with a typical fright reaction, while control fish, with intact olfactory receptors,

Douglas P. Chivers; R. Jan F. Smith

1993-01-01

286

Biological Methylation of Mercury in Aquatic Organisms  

Microsoft Academic Search

FRESHWATER fish, especially pike (Esox lucius), from Sweden sometimes contain abnormally large amounts of mercury1. It was initially concluded to be either inorganic mercury or phenyl mercury, which are known to be released as industrial wastes, but later it was shown that the mercury was present almost entirely as methyl mercury (CH3Hg+)2. A possible explanation is that living organisms have

S. Jensen; A. JERNELÖV

1969-01-01

287

Genetic Divergence among Northern Pike from Spawning Locations in the Upper St. Lawrence River  

Microsoft Academic Search

To assess the ecological consequences associated with the degradation of riparian wetlands that historically provided spawning and rearing habitat for northern pike Esox lucius, annual spawning migrations and genetic structure were used to examine this species' dependence on four specific spawning areas in the Thousand Islands region of the Saint Lawrence River. Tagging and recapture over three consecutive spawning seasons

Aaron Bosworth; John M. Farrell

2006-01-01

288

Ontogenetic niche shifts and resource partitioning in a subarctic piscivore fish guild  

Microsoft Academic Search

The feeding ecology of three piscivorous fish species (perch (Perca fluviatilis), pike (Esox lucius) and burbot (Lota lota)), was studied in the subarctic Pasvik watercourse (69 °?N), northern Norway and Russia. All three species primarily occupied the benthic habitats in the watercourse. Perch and burbot exhibited distinct ontogenetic niche shifts in food resource use, perch changing from a dominance of

Per-Arne Amundsen; Thomas Bøhn; Olga A. Popova; Frode J. Staldvik; Yuri S. Reshetnikov; Nikolay A. Kashulin; Anatoly A. Lukin

2003-01-01

289

Population Characteristics and Ecological Role of Northern Pike in Shallow Natural Lakes in Nebraska  

Microsoft Academic Search

Northern pike Esox lucius were sampled in Nebraska's Sandhill lakes during 1998 and 1999 to determine population characteristics and their influence on the fish community in these shallow, warm lakes at the southwestern edge of this species' natural range. Density-de- pendent growth, size structure, and condition were not evident in the northern pike populations sampled. Relative abundance of largemouth bass

Craig P. Paukert; David W. Willis

2003-01-01

290

Growth, condition, diet, and consumption rates of northern pike in three Arizona reservoirs  

Microsoft Academic Search

Northern pike (Esox lucius L.) introductions are controversial in the western United States due to suspected impacts they might have on established sport fisheries and potential illegal introductions. Three Arizona reservoirs, Parker Canyon Lake, Upper Lake Mary and Long Lake were sampled to examine the diet, consumption dynamics, and growth of northern pike. Northern pike diets varied by season and

Jon M. Flinders; Scott A. Bonar

2008-01-01

291

Catchability of Larval and Juvenile Northern Pike in Quatrefoil Light Traps  

Microsoft Academic Search

New approaches are needed for sampling northern pike Esox lucius in the complex habitats they use as nursery areas. We evaluated the potential of Quatrefoil light traps to measure differences in density of larval and juvenile northern pike, and we monitored changes in capture probability as the fish grew in size and their swimming capabilities improved. In hatchery raceways, light

Rodney B. Pierce; Steve Shroyer; Bruce Pittman; Dale E. Logsdon; Todd D. Kolander

2006-01-01

292

Trophic ecology of largemouth bass and northern pike in allopatric and sympatric assemblages in northern boreal lakes  

Microsoft Academic Search

Largemouth bass (Mieropferus salmoides) and northern pike (Esox lucius) are top predators in the food chain in most aquatic environments that they occupy; however, limited infonnation exists on species interactions in the north­ ern reaches of largemouth bass distribution. We investigated the seasonal food habits of allopatric and sympatric assem­ blages of largemouth bass and northern pike in six interior

Craig A. Soupir; Michael L. Brown; Larry W. Kallemeyn

2000-01-01

293

Structures to Prevent the Spread of Nuisance Fish from Lake Davis, California  

Microsoft Academic Search

Methods to contain the spread of nuisance or otherwise undesirable fish species are relatively limited. I describe an unconventional method used to help restrict the movement of northern pike Esox lucius from a mountain reservoir into downstream waters. Reservoir managers designed, installed, and monitored steel structures (“graters”) that served to increase the likelihood that fish entrained in discharge from Lake

Douglas B. C. Rischbieter

2000-01-01

294

Factors Affecting Growth of Northern Pike in Small Northern Wisconsin Lakes  

Microsoft Academic Search

Fish assemblages that include northern pike Esox lucius as a dominant predator were sampled in 19 small (<120 ha) northern Wisconsin lakes. The purpose of this sampling was to describe northern pike population characteristics and identify factors affecting growth rates. Fish assemblages in these lakes were dominated by centrarchids, primarily bluegill Lepomis macrochirus, and small fusiform species such as yellow

Terry L. Margenau; Paul W. Rasmussen; Jeffrey M. Kampa

1998-01-01

295

FISHING IN THE BYZANTINE FORTRESS OF OLTINA: ARCHAEOZOOLOGICAL DATA  

Microsoft Academic Search

The aim of this research is to assess the importance of fishing in a Byzantine fortress located in southwestern Dobrodja on a bank of the Danube, near the lakeside of Oltina. The site was located in a rich environment with various fishing resources. A number of 11 taxa was identified: Acipenseridae (sturgeons ), Esox lucius (pike), Abramis brama (bream), Aspius

SIMINA STANC; VALENTIN RADU; LUMINITA BEJENARU

296

Management Evaluation of Stocked Northern Pike in Colorado's Small Plains Reservoirs.  

National Technical Information Service (NTIS)

Northern pike (Esox lucius) of two size groups were stocked into several small plains reservoirs in Colorado. Small northern pike approximately 50-mm total length were stocked at an approximate rate of 62/ha, whereas large northern pike averaging 377-mm t...

J. H. Clark

1975-01-01

297

Mercury evolution (1978–1988) in fishes of the La Grande hydroelectric complex, Quebec, Canada  

Microsoft Academic Search

From 1978 to 1988, the evolution of the Hg content of fish has been monitored in the areas affected by the La Grande hydroelectric\\u000a complex. Four fish species were considered: two non piscivorous, lake whitefish (Coregonus clupeaformis) and longnose sucker (Catostomus catostomus), and two piscivorous, northern pike (Esox lucius) and walleye (Stizostedion vitreum). The evolution of Hg concentrations in time

R. Verdon; D. Brouard; C. Demers; R. Lalumiere; M. Laperle; R. Schetagne

1991-01-01

298

Path efficiency of ant foraging trails in an artificial network  

Microsoft Academic Search

In this paper we present an individual-based model describing the foraging behavior of ants moving in an artificial network of tunnels in which several interconnected paths can be used to reach a single food source. Ants lay a trail pheromone while moving in the network and this pheromone acts as a system of mass recruitment that attracts other ants in

Karla Vittori; Grégoire Talbot; Jacques Gautrais; Vincent Fourcassieb; Aluizio F. R. Araújo; Guy Theraulaz

2006-01-01

299

A mathematical and experimental study of ant foraging trail dynamics  

Microsoft Academic Search

In this article, we present a mathematical model coupled to an experimental study of ant foraging trails. Our laboratory experiments on Tetramorium caespitum do not find a strong relationship between ant densities and velocities, a common assumption in traffic modeling. Rather, we find that higher order effects play a major role in observed behavior, and our model reflects this by

Katie Johnson; Louis F. Rossi

2006-01-01

300

Two-level evolution of foraging agent communities  

Microsoft Academic Search

This paper presents simulation results of artificial foraging agent communities. The goal of each agent in the community is to find food. Once a food source is found, agents eat portions of it and carry some other portions to the nest (in a manner similar to ants) until the food is depleted. Agents may also communicate food positions when they

Manuel Alfonseca; Juan de Lara

2002-01-01

301

Decomposition of Arachis pintoi litter intercropped with forage grass in \\  

Microsoft Academic Search

In tropical pastures which are generally under utilized, nutrients are returned to the soil mainly via litter decomposition. However little is known about the decomposition of tropical forage species in pastures. In this work the dynamics of Arachis pintoi litter decomposition was studied, in the \\

C. Oliveira; M. Scotti; H. Purcino; C. Vasconcellos; I. Marriel; N. Sá

2002-01-01

302

People's Study Time Allocation and its Relation to Animal Foraging  

PubMed Central

In this article we suggest a relation between people's metacognitively guided study time allocation strategies and animal foraging. These two domains are similar insofar as people use specific metacognitive cues to assist their study time allocation just as other species use cues, such as scent marking. People decline to study items that they know they already know, just as other species use a win-shift strategy – avoiding already visited and depleted patches – in foraging. People selectively study the easiest as-yet-unlearned items first, before turning to more difficult items just as other species take the ‘just right’ size and challenge of prey--the so-called Goldilocks principle. People use a stop rule by which they give up on one item and turn to another when the returns diminish just as others species use a stop rule that guides shifting from one patch to another. The value that each item is assigned on the criterion test, if known during study, influenced which items people choose to study and how long they study them just as knowledge of the nutritional or energy value of the food influences choices and perseverance in foraging. Finally, study time allocation strategies can differ in their effectiveness depending upon the expertise of the student just as some species forage close to optimally while others do not.

Metcalfe, Janet; Jacobs, W. Jake

2010-01-01

303

Forage Quality and Rumination Time in Cattle[1] and [2  

Microsoft Academic Search

Three experiments investigated how for- ages of different chemical composition affect rumination time of cattle. Three single reversal designs used four dairy heifers and two dairy steers in Experi- ment I and four dairy heifers in Experi- ments II and III. The rumination time produced by feeding a single 5-kg meal of test forage was measured with jaw mo- tion

J. G. Welch; A. M. Smith

1970-01-01

304

Light intensity limits foraging activity in nocturnal and crepuscular bees  

Microsoft Academic Search

A crepuscular or nocturnal lifestyle has evolved in bees several times independently, probably to explore rewarding pollen sources without competition and to minimize predation and nest parasites. Despite these obvious advantages, only few bee species are nocturnal. Here we show that the sensitivity of the bee apposition eye is a major factor limiting the ability to forage in dim light.

Almut Kelber; Eric J. Warrant; Michael Pfaff; Rita Wallen; Jamie C. Theobald; William T. Wcislo

2005-01-01

305

Foraging Ecology of Pileated Woodpeckers in Coastal Forests of Washington  

Microsoft Academic Search

In the Pacific Northwest, providing adequate habitat forpileated woodpeckers (Dryocopus pileatus) has been a key component Of federal forest management strategies for over 20 years. Although their nesting and roosting ecology has been well studied, information on their foraging ecology is limited. From 1990 to 1995, we studied food habits of pileated woodpeckers in coastal forests (with scat analysis); estimated

CATHERINE M. RALEY; KEITH B. AUBRY

2006-01-01

306

FORAGE DIVERSITY AND WEED ABUNDANCE RELATIONSHIPS IN GRAZED PASTURE COMMUNITIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Studies have shown that weed invasion into grasslands may be suppressed in diverse plant communities. Our main objective was to determine whether increased forage plant diversity in pasture communities could help reduce weed abundance in the aboveground vegetation and soil seed bank. We also teste...

307

Green Crab (Carcinus maenas) Foraging Efficiency Reduced by Fast Flows  

PubMed Central

Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is invading marine habitats throughout the world. High flow velocities are known to reduce green crab predation rates and our study sought to identify the mechanisms by which flow affects green crabs. We performed a series of experiments with green crabs to determine: 1) if their ability to find prey was altered by flow in the field, 2) how flow velocity influenced their foraging efficiency, and 3) how flow velocity affected their handling time of prey. In a field study, we caught significantly fewer crabs in baited traps at sites with fast versus slow flows even though crabs were more abundant in high flow areas. This finding suggests that higher velocity flows impair the ability of green crabs to locate prey. In laboratory flume assays, green crabs foraged less efficiently when flow velocity was increased. Moreover, green crabs required significantly more time to consume prey in high velocity flows. Our data indicate that flow can impose significant chemosensory and physical constraints on green crabs. Hence, hydrodynamics may strongly influence the role that green crabs and other predators play in rocky intertidal communities.

Robinson, Elizabeth M.; Smee, Delbert L.; Trussell, Geoffrey C.

2011-01-01

308

Foraging success of biological Lévy flights recorded in situ.  

PubMed

It is an open question how animals find food in dynamic natural environments where they possess little or no knowledge of where resources are located. Foraging theory predicts that in environments with sparsely distributed target resources, where forager knowledge about resources' locations is incomplete, Lévy flight movements optimize the success of random searches. However, the putative success of Lévy foraging has been demonstrated only in model simulations. Here, we use high-temporal-resolution Global Positioning System (GPS) tracking of wandering (Diomedea exulans) and black-browed albatrosses (Thalassarche melanophrys) with simultaneous recording of prey captures, to show that both species exhibit Lévy and Brownian movement patterns. We find that total prey masses captured by wandering albatrosses during Lévy movements exceed daily energy requirements by nearly fourfold, and approached yields by Brownian movements in other habitats. These results, together with our reanalysis of previously published albatross data, overturn the notion that albatrosses do not exhibit Lévy patterns during foraging, and demonstrate that Lévy flights of predators in dynamic natural environments present a beneficial alternative strategy to simple, spatially intensive behaviors. Our findings add support to the possibility that biological Lévy flight may have naturally evolved as a search strategy in response to sparse resources and scant information. PMID:22529349

Humphries, Nicolas E; Weimerskirch, Henri; Queiroz, Nuno; Southall, Emily J; Sims, David W

2012-04-23

309

Novel forages for growth and health in farmed deer  

Microsoft Academic Search

AIMS: This paper reviews recent research on the use of new forages in deer farming that may be useful for increasing growth in weaner deer for venison production, increasing the trace element status of deer, and for developing systems less reliant on chemical inputs, notably of anthelmintics used to control internal parasites.GROWTH: Grazing on pure swards of red clover (Trifolium

TN Barry; SO Hoskin; PR Wilson

2002-01-01

310

Foraging selectivity of three goat breeds in a Mediterranean shrubland  

Microsoft Academic Search

Foraging behaviors of the Damascus, Mamber and Boer goat breeds were compared on shrublands of the South Carmel mountain ridge of Israel. Dietary choice was determined for a group of yearling animals of each breed (n=11 or 12), housed and grazed separately to prevent social facilitation, during a total of 4 (Mamber) or 5 (Damascus and Boer) sessions of four

T. A. Glasser; S. Y. Landau; E. D. Ungar; A. Perevolotsky; L. Dvash; H. Muklada; D. Kababya; J. W. Walker

311

Forest disturbance type differentially affects seasonal moose forage  

Treesearch

Diet samples mixed in the proportions eaten in the field and representing the ... to 47% [fall (80) on defoliated-clearcut and defoliated-clearcut-burned (combined) and ... Forage production, up to 6 growing-seasons post-treatment, was reduced  ...

312

The Value of Uncropped Field Margins For Foraging Bumblebees  

Microsoft Academic Search

The intensification of agriculture has led to declines in species diversity and abundance within groups of certain flora and fauna. Bumblebees (Bombus spp.) are one group where a decline has been documented, and it is thought to be attributable to a decrease in forage resources and potential nest sites. As bumblebees play an important role in the pollination of many

Andrea R. Kells; John M. Holland; Dave Goulson

2001-01-01

313

Terrestrial Foraging by Two Species of Semiaquatic Turtles (Testudines: Emydidae)  

Microsoft Academic Search

I describe terrestrial foraging behavior in Trachemys scripta elegans (Red-eared Slider) and Graptemys pseudogeographica kohnii (Mississippi Map Turtle), two species of semiaquatic turtles. I observed specimens of Red-eared Slider on two occasions in two differ- ent locations climbing onto the bank of a stream and consuming grass blades (Luziola fl uitans (Southern Watergrass) and Eragrostis hypnoides (Teal Lovegrass)), which were

John L. Carr

2008-01-01

314

Adaptive L?vy Walks in Foraging Fallow Deer  

PubMed Central

Background Lévy flights are random walks, the step lengths of which come from probability distributions with heavy power-law tails, such that clusters of short steps are connected by rare long steps. Lévy walks maximise search efficiency of mobile foragers. Recently, several studies raised some concerns about the reliability of the statistical analysis used in previous analyses. Further, it is unclear whether Lévy walks represent adaptive strategies or emergent properties determined by the interaction between foragers and resource distribution. Thus two fundamental questions still need to be addressed: the presence of Lévy walks in the wild and whether or not they represent a form of adaptive behaviour. Methodology/Principal Findings We studied 235 paths of solitary and clustered (i.e. foraging in group) fallow deer (Dama dama), exploiting the same pasture. We used maximum likelihood estimation for discriminating between a power-tailed distribution and the exponential alternative and rank/frequency plots to discriminate between Lévy walks and composite Brownian walks. We showed that solitary deer perform Lévy searches, while clustered animals did not adopt that strategy. Conclusion/Significance Our demonstration of the presence of Lévy walks is, at our knowledge, the first available which adopts up-to-date statistical methodologies in a terrestrial mammal. Comparing solitary and clustered deer, we concluded that the Lévy walks of solitary deer represent an adaptation maximising encounter rates with forage resources and not an epiphenomenon induced by a peculiar food distribution.

Focardi, Stefano; Montanaro, Paolo; Pecchioli, Elena

2009-01-01

315

Finger millet: An alternative forage crop for Southern High Plains  

Technology Transfer Automated Retrieval System (TEKTRAN)

In the Southern High Plains, dairies are expanding to take advantage of favorable climatic conditions. Currently corn (Zea mays L.) and forage sorghum (Sorghum bicolor (L.) Moench) are the two major crops grown in the region to meet the current silage demand. Corn and sorghum have relatively large w...

316

Green crab (Carcinus maenas) foraging efficiency reduced by fast flows.  

PubMed

Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is invading marine habitats throughout the world. High flow velocities are known to reduce green crab predation rates and our study sought to identify the mechanisms by which flow affects green crabs. We performed a series of experiments with green crabs to determine: 1) if their ability to find prey was altered by flow in the field, 2) how flow velocity influenced their foraging efficiency, and 3) how flow velocity affected their handling time of prey. In a field study, we caught significantly fewer crabs in baited traps at sites with fast versus slow flows even though crabs were more abundant in high flow areas. This finding suggests that higher velocity flows impair the ability of green crabs to locate prey. In laboratory flume assays, green crabs foraged less efficiently when flow velocity was increased. Moreover, green crabs required significantly more time to consume prey in high velocity flows. Our data indicate that flow can impose significant chemosensory and physical constraints on green crabs. Hence, hydrodynamics may strongly influence the role that green crabs and other predators play in rocky intertidal communities. PMID:21687742

Robinson, Elizabeth M; Smee, Delbert L; Trussell, Geoffrey C

2011-06-07

317

IMPACT OF CELL WALL LIGNIFICATION ON FORAGE DIGESTIBILITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Existence of a negative relationship between lignin concentration and digestibility of forages has been known for more than 50 years; however, understanding the causal factors has proven difficult. Lignin is a polymer composed of phenylpropanoid units. The biosynthetic pathway for lignin precursor s...

318

Foraging Behavior of Beaked Whales and Other Deep Diving Odontocetes.  

National Technical Information Service (NTIS)

The long-term goal of our research is to understand beaked whale foraging process and to learn how to alleviate acoustic encounters between Navy asserts and beaked whales and other deep diving odontocetes. The more specific goal of this proposal is to fab...

M. O. Lammers W. W. Au

2010-01-01

319

Foraging segregation between two closely related shearwaters breeding in sympatry  

PubMed Central

Trophic segregation has been proposed as a major mechanism explaining the coexistence of closely related animal taxa. However, how such segregation varies throughout the annual cycle is poorly understood. Here, we examined the feeding ecology of the two subspecies of Cory's shearwater, Calonectris diomedea diomedea and Calonectris diomedea borealis, breeding in sympatry in a Mediterranean colony. To study trophic segregation at different stages, we combined the analysis of isotope values (? 15N, ? 13C) in blood obtained during incubation and in feathers moulted during chick-rearing and wintering periods with satellite-tracking data during the chick-rearing period. Satellite-tracking and stable isotope data of the first primary feather revealed that C. d. borealis foraged mainly in the Atlantic whereas C. d. diomedea foraged exclusively in the Mediterranean. This spatial segregation could reflect the foraging behaviour of the C. d. borealis individuals before they arrived at the Mediterranean colony. Alternatively, greater wing loading of C. d. borealis individuals may confer the ability to fly across the strong winds occurring at the at the Gibraltar strait. Isotope values of the eighth secondary feather also support segregation in wintering areas between the two forms: C. d. diomedea wintered mainly in association with the Canary current, whereas C. d. borealis wintered in the South African coast. Overall, our results show that spatial segregation in foraging areas can display substantial variation throughout the annual cycle and is probably a major mechanism facilitating coexistence between closely related taxa.

Navarro, Joan; Forero, Manuela G.; Gonzalez-Solis, Jacob; Igual, Jose Manuel; Becares, Juan; Hobson, Keith A.

2009-01-01

320

Conservation and enrichment of forages by ensiling with poultry excreta  

Microsoft Academic Search

In this study, ensiling of poultry manure with some tropical forages was investigated as a management option for poultry wastes. Water hyacinth (Eichhornia cassipes) and Guinea grass (Panicum maximum) were ensiled with caged layer excreta (CLE) to enhance the nutritional value of the resultant fodder. Levels of CLE inclusion investigated ranged from 0% (control) to 50% (fresh weight basis). The

R. Mson; A. Y. Sangodoyin

1995-01-01

321

Foraging behaviour of Weddell seals, and its ecological implications  

Microsoft Academic Search

Time-depth recorder data of eight adult Weddell seals (Leptonychotes weddellii) provided simultaneous dive records over 8 days in the Drescher Inlet, eastern Weddell Sea coast, in February 1998. The seals primarily foraged within two depth layers, these being from the sea surface to 160 m where temperature and salinity varied considerably, and near the bottom from 340 to 450 m

Joachim Plötz; Horst Bornemann; Rainer Knust; Alexander Schröder; Marthan Bester

2001-01-01

322

Nutritive value response of forage chicory cultivars to phosphorus fertility  

Technology Transfer Automated Retrieval System (TEKTRAN)

Forage chicory (Cichorium intybus L.) is a productive plant that appears particularly well suited to improving summer yield of pastures in the USA. Poor palatability of some chicory cultivars in locations with low soil phosphorus fertility has been linked to high levels of sesquiterpene lactones, b...

323

Sampling requirements for forage quality characterization of rectangular hay bales  

SciTech Connect

Commercial lots of alfalfa (Medicago sativa L.) hay are often bought and sold on the basis of forage quality. Proper sampling is essential to obtain accurate forage quality results for pricing of alfalfa hay, but information about sampling is limited to small, 20- to 40-kg rectangular bales. Their objectives were to determine the within-bale variation in 400-kg rectangular bales and to determine the number and distribution of core samples required to represent the crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and dry matter (DM) concentration in commercial lots of alfalfa hay. Four bales were selected from each of three hay lots and core sampled nine times per side for a total of 54 cores per bale. There was no consistent pattern of forage quality variation within bales. Averaged across lots, any portion of a bale was highly correlated with bale grand means for CP, ADF, NDF, and DM. Three lots of hay were probed six times per bale, one core per bale side from 55, 14, and 14 bales per lot. For determination of CP, ADF, NDF, and DM concentration, total core numbers required to achieve an acceptable standard error (SE) were minimized by sampling once per bale. Bootstrap analysis of data from the most variable hay lot suggested that forage quality of any lot of 400-kg alfalfa hay bales should be adequately represented by 12 bales sampled once per bale.

Sheaffer, C.C.; Martin, N.P.; Jewett, J.G.; Halgerson, J.; Moon, R.D.; Cuomo, G.R.

2000-02-01

324

Use of biosolids to enhance rangeland forage quality.  

PubMed

Biosolids land application was demonstrated to be a potentially cost-effective means for restoring forage productivity and enhancing soil-moisture-holding capacity on disturbed rangelands. By land-applying aerobically digested, anaerobically digested, composted, and lime-stabilized biosolids on rangeland test plots at rates of up to 20 times (20X) the estimated nitrogen-based agronomic rate, forage yields were found to increase from 132.8 kg/ha (118.2 lb/ac) (control plots) to 1182.3 kg/ha (1052.8 lb/ac). Despite the environmental benefits associated with increased forage yield (e.g., reduced soil erosion, improved drainage, and enhanced terrestrial carbon sequestration), the type of forage generated both before and after biosolids land application was found to be dominated by invasive weeds, all of which were characterized as having fair to poor nutritional value. Opportunistic and shallow rooting invasive weeds not only have marginal nutritional value, they also limit the establishment of native perennial grasses and thus biodiversity. Many of the identified invasive species (e.g., Cheatgrass) mature early, a characteristic that significantly increases the fuel loads that support the increased frequency and extent of western wildfires. PMID:20480767

McFarland, Michael J; Vasquez, Issaak Romero; Vutran, MaiAnh; Schmitz, Mark; Brobst, Robert B

2010-05-01

325

FORAGING SITE SELECTION BY NONBREEDING WHITE-FACED IBIS  

Microsoft Academic Search

We examined foraging site selection by White-faced Ibis (Plegadis chihi) wintering in the Grasslands Ecological Area, which contains the second largest population of nonbreeding ibis in California. We compared habitat variables at White-faced Ibis for- aging sites with paired, random locations in managed wetlands of the Grasslands. We contrasted the density and biomass of benthic macroinvertebrates between a subsample of

Rebecca J. Safran; Mark A. Colwell; Craig R. Isola; Oriane E. Taft

2000-01-01

326

Convergence and rate of convergence of a foraging ant model  

Microsoft Academic Search

ó We present an ant model that solves a discrete foraging problem. We describe simulations and provide a complete convergence analysis: we show that the ant population computes the solution of some optimal control problem and converges in some well dened sense. We discuss the rate of convergence with respect to the number of ants: we give experimental and theoretical

Amine M. Boumaza; Bruno Scherrer

2007-01-01

327

Potential energetic effects of mountain climbers on foraging grizzly bears  

USGS Publications Warehouse

Most studies of the effects of human disturbance on grizzly bears (Ursus arctos horribilis) have not quantified the energetic effects of such interactions. In this study, we characterized activity budgets of adult grizzly bears as they foraged on aggregations of adult army cutworm moths (Euxoa auxiliaris) in the alpine of Glacier National Park, Montana, during 1992, 1994, and 1995. We compared the activity budgets of climber-disturbed bears to those of undisturbed bears to estimate the energetic impact of climber disturbance. When bears detected climbers, they subsequently spent 53% less time foraging on moths, 52% more time moving within the foraging area, and 23% more time behaving aggressively, compared to when they were not disturbed. We estimated that grizzly bears could consume approximately 40,000 moths/day or 1,700 moths/hour. At 0.44 kcal/moth, disruption of moth feeding cost bears approximately 12 kcal/minute in addition to the energy expended in evasive maneuvers and defensive behaviors. To reduce both climber interruption of bear foraging and the potential for aggressive bear-human encounters, we recommend routing climbers around moth sites used by bears or limiting access to these sites during bear-use periods.

White, Jr. , D.; Kendall, K. C.; Picton, H. D.

1999-01-01

328

DETERMINING FORAGE QUALITY IN SITU USING REMOTE SENSING  

Technology Transfer Automated Retrieval System (TEKTRAN)

A critical shortcoming in the management of grazing lands is the inability to quantify the quality of live, standing forages on pastures in real-time. This information is needed to make informed land and livestock management decisions. The objective of this study was to determine the feasibility o...

329

FORAGE ENERGY CROPS AS FEEDSTOCKS FOR PRODUCTION OF FUEL ETHANOL  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alfalfa, reed canarygrass, and switchgrass are perennial herbaceous species that have potential as biomass energy crops in temperate regions. Each forage species was harvested at two or three maturity stages and analyzed for carbohydrates, lignin, protein, lipid, organic acids, and mineral composit...

330

BOTANICAL COMPOSITION AND FORAGE PRODUCTION IN AN EMULATED SILVOPASTURE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Integrating trees into pasture may increase pasture production and improve nutritive value by altering both species composition and productivity. Our objective was to determine forage yield and botanical composition in response to tree species, tree density, and slope position in an emulated silvop...

331

In Vitro Digestion Rate of Forage Cell Wall Components  

Microsoft Academic Search

Linearity of the semilog plots of remain- ing digestible fiber on time and their corre- lations (r = .98 approximately) indicated first order digestion kinetics for each of the six forages even though composition and observed rates of fiber digestion were markedly different. Immature rye cell walls digested fastest (27.03 ± .81%\\/ hour, r 2 -- .999) and mature timothy

L. W. Smith; H. K. Goering; D. R. Waldo; C. H. Gordon

1971-01-01

332

Implications of an altered climate for forage conservation  

Microsoft Academic Search

Conservation of grass forage for winter feeding of ruminant livestock is one of the most weather dependent of all farm operations, so a change in climate is likely to have a major impact on conservation practices. A weather driven whole system model previously used to study a range of hay and silage conservation methods, practices and mechanisation systems, has been

Gillian Cooper; Malcolm B. McGechan

1996-01-01

333

Modeling ant colony foraging in dynamic and confined environment  

Microsoft Academic Search

The collective foraging behavior of ants is an example of self-organization and adaptation arising from the superposition of simple individual behavior. With the objective of understanding and modeling such interactions, experiments with the Argentine ants Linepithema humile were conducted into a relatively complex, artificial network. This consisted of interconnected branches and bifurcations, where the ants have to choose among fourteen

Elton Bernardo Bandeira De Melo; Aluízio Fausto Ribeiro Araújo

2008-01-01

334

Nutrient compensatory foraging in a free-living social insect  

NASA Astrophysics Data System (ADS)

The geometric framework model predicts that animal foraging decisions are influenced by their dietary history, with animals targeting a combination of essential nutrients through compensatory foraging. We provide experimental confirmation of nutrient-specific compensatory foraging in a natural, free-living population of social insects by supplementing their diet with sources of protein- or carbohydrate-rich food. Colonies of the ant Iridomyrmex suchieri were provided with feeders containing food rich in either carbohydrate or protein for 6 days, and were then provided with a feeder containing the same or different diet. The patterns of recruitment were consistent with the geometric framework: while feeders with a carbohydrate diet typically attracted more workers than did feeders with protein diet, the difference in recruitment between the two nutrients was smaller if the colonies had had prior access to carbohydrate than protein. Further, fewer ants visited feeders if the colony had had prior access to protein than to carbohydrates, suggesting that the larvae play a role in worker foraging behaviour.

Christensen, Keri L.; Gallacher, Anthony P.; Martin, Lizzie; Tong, Desmond; Elgar, Mark A.

2010-10-01

335

TEMPORAL FORAGING ACTIVITY OF SELECTED ANT SPECIES IN NORTHERN MISSISSIPPI.  

Technology Transfer Automated Retrieval System (TEKTRAN)

A experiment was conducted in northeastern Mississippi to examine temporal foraging activity of imported fire ants and other common ant species that inhabit pasture and meadow areas. Baited vials were placed horizontally on the ground along straight-line transects (N = 21) every 3 h for 24 h period...

336

Forage quantity estimation from MERIS using band depth parameters  

Microsoft Academic Search

Saleem Ullah1 , Si Yali1 , Martin Schlerf1 Forage quantity is an important factor influencing feeding pattern and distribution of wildlife. The main objective of this study was to evaluate the predictive performance of vegetation indices and band depth analysis parameters for estimation of green biomass using MERIS data. Green biomass was best predicted by NBDI (normalized band depth index)

Saleem Ullah; Si Yali; Martin Schlerf

2010-01-01

337

Forage Systems for Minimizing Hay and Concentrate Needs  

Technology Transfer Automated Retrieval System (TEKTRAN)

Cattlemen typically simplify their pasture management by relying on one or two forages that are well adapted and persist under their targeted levels of management and production. The 5.5 million acres of Kentucky-31 tall fescue in Kentucky is a strong indication how producers in the state rely on t...

338

Harvest management of switchgrass for biomass feedstock and forage production  

Microsoft Academic Search

Switchgrass (Panicum virgatum L.), a warm-season perennial grass native to North America, has potential as a biomass energy crop. Their objective was to develop harvest management recommendations for biomass feedstock and forage production. Alamo switchgrass was established in 1992 at Stephenville and Dallas, TX. Four harvest frequencies (one to four cuts per year) and three final autumn harvests (Sept., Oct.,

Matt A. Sanderson; James C. Read; Roderick L. Reed

1999-01-01

339

Light intensity limits foraging activity in nocturnal and crepuscular bees  

Microsoft Academic Search

A crepuscular or nocturnal lifestyle has evolved in bees several times independently, probably to explore rewarding pollen sources without competition and to minimize predation and nest parasites. Despite these obvious advantages, only few bee species are nocturnal. Here we show that the sensitivity of the bee apposition eye is a major factor limiting the ability to forage in dim light.

Almut Kelber; Eric J. Warrant; Michael Pfaff; Rita Wallén; Jamie C. Theobald; William T. Wcislo; Robert A. Raguso

2006-01-01

340

Resource defense in a group-foraging context  

Microsoft Academic Search

When foraging in groups, animals frequently use either scramble or contest tactics to obtain food at clumps found by others. The question of which competitive tactic should be used has been addressed from two different perspectives: a simple optimality approach and a game theoretic approach. Surprisingly, both approaches make strikingly different predictions about how per-capita frequency of aggression within groups

Fre´de´rique Dubois; Luc-Alain Giraldeau; James W. A. Grantb

2003-01-01

341

Habitat selection and web plasticity by the orb spider Argiope keyserlingi (Argiopidae): Do they compromise foraging success for predator avoidance?  

Microsoft Academic Search

Orb web spiders face a dilemma: forage in open habitats and risk predation or forage in closed habitats to minimize risk but at reduced foraging profitability.We tested whether Argiope keyserlingi opts for safer habitats at the expense of foraging success by (i) determining habitat selection indices in open and closed habitats; (ii) marking and releasing individual juvenile, subadult and adults

SEAN J. BLAMIRES; MICHAEL B. THOMPSON; DIETER F. HOCHULI

2007-01-01

342

Effects of Corn Silage Hybrid and Dietary Concentration of Forage NDF on Digestibility and Performance by Dairy Cows1  

Microsoft Academic Search

Eight intact multiparous cows and four ruminally and duodenally cannulated primiparous cows were fed four diets in a replicated 4 × 4 Latin square design: 1) 17% forage neutral detergent fiber (NDF) with brown midrib corn silage (BMRCS), 2) 21% forage NDF with BMRCS, 3) 17% forage NDF with conventional corn silage (CCS), and 4) 21% forage NDF with CCS.

X. Qiu; M. L. Eastridge; Z. Wang

2003-01-01

343

Cognitive abilities of a central place forager interact with prey spatial aggregation in their effect on intake rate  

Microsoft Academic Search

When foraging in a landscape, predators choose travelling directions according to their immediate knowledge of prey distribution within their perceptual fields and, when appropriate, to their past foraging experience. A substantial part of foraging theory is based on patch use in spatially implicit domains, and rarely has it considered foraging paths involving directional choices driven by memory and perception. Using

F. Barraquand; P. Inchausti; V. Bretagnolle

2009-01-01

344

Individual foraging, activity level and longevity in the stingless bee Melipona beecheii in Costa Rica (Hymenoptera, Apidae, Meliponinae)  

Microsoft Academic Search

Summary: Foraging behaviour of individually marked workers of Melipona beecheii (Meliponinae) was monitored in Costa Rica to investigate individual specialisation for different materials and how this influences foraging longevity. The majority of the individuals harvested one commodity (pollen, nectar or resin) during a single day. Half of the age-marked foragers specialised on nectar or pollen during their complete foraging career,

J. C. Biesmeijer; E. Tóth

1998-01-01

345

FORAGING ECOLOGY OF SYMPATRIC PARIDS: INDIVIDUAL AND POPULATION RESPONSES TO WINTER FOOD SCARCITY (COMPETITION, NICHE, BEHAVIOR, OVERLAP)  

Microsoft Academic Search

This study investigated individual variation in foraging behavior in response to seasonal food shortage in populations of Carolina Chickadees (Parus carolinensis) and Tufted Titmice (Parus bicolor) at the Ross Biological Reserve, Tippecanoe County, Indiana. Each individual was banded, sexed, measured (wing, beak, and tarsus lengths), and observed to quantify foraging behavior in the field (foraging height, foraging distance from trunk,

KUMTHORN THIRAKHUPT

1985-01-01

346

Foraging strategy quick response to temperature of Messor barbarus (Hymenoptera: Formicidae) in Mediterranean environments.  

PubMed

Animals principally forage to try to maximize energy intake per unit of feeding time, developing different foraging strategies. Temperature effects on foraging have been observed in diverse ant species; these effects are limited to the duration of foraging or the number of foragers involved. The harvester ant Messor barbarus L. 1767 has a specialized foraging strategy that consists in the formation of worker trails. Because of the high permeability of their body integument, we presume that the length, shape, and type of foraging trails of M. barbarus must be affected by temperature conditions. From mid-June to mid-August 1999, we tested the effect on these trail characteristics in a Mediterranean forest. We found that thermal stress force ants to use a foraging pattern based on the variation of the workers trail structure. Ants exploit earlier well-known sources using long physical trails, but as temperatures increases throughout the morning, foragers reduce the length of the foraging column gradually, looking for alternative food sources in nonphysical trails. This study shows that animal forage can be highly adaptable and versatile in environments with high daily variations. PMID:18801249

Doblas-Miranda, Enrique; Reyes-López, Joaquín

2008-08-01

347

Effects of Termperature and Season on Foraging Activity of Red Imported Fire Ants (Hymenoptera: Formicidae) Foraging in Oklahoma  

Technology Transfer Automated Retrieval System (TEKTRAN)

Temperature and seasonal effects on foraging activity of Solenopsis invicta Buren (red imported fire ant) in Oklahoma were investigated by periodically quantifying the number of ants captured in baited vials for 1 yr. All temperature measurements except ambient at 1 m above soil surface (surface, 2...

348

Foraging Fidelity as a Recipe for a Long Life: Foraging Strategy and Longevity in Male Southern Elephant Seals  

PubMed Central

Identifying individual factors affecting life-span has long been of interest for biologists and demographers: how do some individuals manage to dodge the forces of mortality when the vast majority does not? Answering this question is not straightforward, partly because of the arduous task of accurately estimating longevity in wild animals, and of the statistical difficulties in correlating time-varying ecological covariables with a single number (time-to-event). Here we investigated the relationship between foraging strategy and life-span in an elusive and large marine predator: the Southern Elephant Seal (Mirounga leonina). Using teeth recovered from dead males on îles Kerguelen, Southern Ocean, we first aged specimens. Then we used stable isotopic measurements of carbon () in dentin to study the effect of foraging location on individual life-span. Using a joint change-point/survival modelling approach which enabled us to describe the ontogenetic trajectory of foraging, we unveiled how a stable foraging strategy developed early in life positively covaried with longevity in male Southern Elephant Seals. Coupled with an appropriate statistical analysis, stable isotopes have the potential to tackle ecological questions of long standing interest but whose answer has been hampered by logistic constraints.

Authier, Matthieu; Bentaleb, Ilham; Ponchon, Aurore; Martin, Celine; Guinet, Christophe

2012-01-01

349

Comparison of sorghum classes for forage and grain yield, forage nutritive value, agronomic characteristics, nutrient composition, and fiber digestibility  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sorghum represents a broad category of plants that includes those grown primarily for forage (FS) or grain. Sorghum sudan crosses (SS) are also considered sorghum. Each of these groups can be further classified as brown midrib (BMR), nonBMR, photoperiod sensitive (PS), and nonPS. In our study, sor...

350

Forage yield of grass-alfalfa and grass-forage kochia mixtues on semi-arid rangelands  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increased productivity of semiarid western U.S.A. grazing lands is possible with the appropriate plant material combinations. The objective of this study was to compare late summer forage yield of 'Vavilov' Siberian wheatgrass (Agropyron fragile) and 'Mustang' altai wildrye (Leymus angustus) in bin...

351

Shifting the balance between foraging and predator avoidance: the importance of food distribution for a schooling pelagic forager  

Microsoft Academic Search

It is widely held that when predator avoidance conflicts with other activities, such as feeding, avoidance of predators often takes precedence. In this study, we examine how predation risk and food distribution interact to influence the schooling behavior and swimming speed of foraging juvenile walleye pollock, Theragra chalcogramma. Fish were acclimated to either spatially and temporally clumped, or spatially and

Clifford H. Ryer; Bori L. Olla

1998-01-01

352

Fearful Foragers: Honey Bees Tune Colony and Individual Foraging to Multi-Predator Presence and Food Quality  

PubMed Central

Fear can have strong ecosystem effects by giving predators a role disproportionate to their actual kill rates. In bees, fear is shown through foragers avoiding dangerous food sites, thereby reducing the fitness of pollinated plants. However, it remains unclear how fear affects pollinators in a complex natural scenario involving multiple predator species and different patch qualities. We studied hornets, Vespa velutina (smaller) and V. tropica (bigger) preying upon the Asian honey bee, Apis cerana in China. Hornets hunted bees on flowers and were attacked by bee colonies. Bees treated the bigger hornet species (which is 4 fold more massive) as more dangerous. It received 4.5 fold more attackers than the smaller hornet species. We tested bee responses to a three-feeder array with different hornet species and varying resource qualities. When all feeders offered 30% sucrose solution (w/w), colony foraging allocation, individual visits, and individual patch residence times were reduced according to the degree of danger. Predator presence reduced foraging visits by 55–79% and residence times by 17–33%. When feeders offered different reward levels (15%, 30%, or 45% sucrose), colony and individual foraging favored higher sugar concentrations. However, when balancing food quality against multiple threats (sweeter food corresponding to higher danger), colonies exhibited greater fear than individuals. Colonies decreased foraging at low and high danger patches. Individuals exhibited less fear and only decreased visits to the high danger patch. Contrasting individual with emergent colony-level effects of fear can thus illuminate how predators shape pollination by social bees.

Tan, Ken; Hu, Zongwen; Chen, Weiwen; Wang, Zhengwei; Wang, Yuchong; Nieh, James C.

2013-01-01

353

Fearful foragers: honey bees tune colony and individual foraging to multi-predator presence and food quality.  

PubMed

Fear can have strong ecosystem effects by giving predators a role disproportionate to their actual kill rates. In bees, fear is shown through foragers avoiding dangerous food sites, thereby reducing the fitness of pollinated plants. However, it remains unclear how fear affects pollinators in a complex natural scenario involving multiple predator species and different patch qualities. We studied hornets, Vespa velutina (smaller) and V. tropica (bigger) preying upon the Asian honey bee, Apis cerana in China. Hornets hunted bees on flowers and were attacked by bee colonies. Bees treated the bigger hornet species (which is 4 fold more massive) as more dangerous. It received 4.5 fold more attackers than the smaller hornet species. We tested bee responses to a three-feeder array with different hornet species and varying resource qualities. When all feeders offered 30% sucrose solution (w/w), colony foraging allocation, individual visits, and individual patch residence times were reduced according to the degree of danger. Predator presence reduced foraging visits by 55-79% and residence times by 17-33%. When feeders offered different reward levels (15%, 30%, or 45% sucrose), colony and individual foraging favored higher sugar concentrations. However, when balancing food quality against multiple threats (sweeter food corresponding to higher danger), colonies exhibited greater fear than individuals. Colonies decreased foraging at low and high danger patches. Individuals exhibited less fear and only decreased visits to the high danger patch. Contrasting individual with emergent colony-level effects of fear can thus illuminate how predators shape pollination by social bees. PMID:24098734

Tan, Ken; Hu, Zongwen; Chen, Weiwen; Wang, Zhengwei; Wang, Yuchong; Nieh, James C

2013-09-30

354

Foraging tactics of chick-rearing Crozet shags: individuals display repetitive activity and diving patterns over time  

Microsoft Academic Search

It is in the interest of resident and long-lived benthic foragers to learn to apply efficient foraging tactics throughout their lifetime, thus increasing their individual efficiency. To test whether individuals are capable of applying an individual-specific foraging pattern, we checked for the existence of established foraging routines. Using ventrally attached time-depth recorders, we studied the individual foraging tactics of chick-rearing

Timothée R. Cook; Yves Cherel; Yann Tremblay

2006-01-01

355

Partial Replacement of Forage with Nonforage Fiber Sources in Lactating Cow Diets. II. Digestion and Rumen Function  

Microsoft Academic Search

Replacement of forage with cereal byproducts may be a viable alternative for feeding dairy cows. The objec- tive of this experiment was to evaluate total tract diges- tion and rumen fermentation profile when diets were formulated to contain low-forage neutral detergent fi- ber (NDF) (12.6% forage NDF, 18.8% total NDF), ade- quate NDF from forages (20% forage NDF, 24.4% total

M. N. Pereira; L. E. Armentano

2000-01-01

356

Persistence, reticence and the management of multiple time memories by forager honey bees.  

PubMed

Honey bee foragers form time memories that enable them to match their foraging activity to the time of day when a particular food source is most productive. Persistent foragers show food-anticipatory activity by making reconnaissance flights to the previously productive food source and may continue to inspect it for several days. In contrast, reticent foragers do not investigate the source but wait for confirmation from returning persistent foragers. To determine how persistent and reticent foragers might contribute to the colony's ability to rapidly reallocate foragers among sources, we trained foragers to collect sucrose from a feeder at a restricted time of day for several days and then observed their behavior for three consecutive days during which the feeder was empty. In two separate trials, video monitoring of the hive entrance during unrewarded test days in parallel with observing reconnaissance visits to the feeder revealed a high level of activity, in both persistent and reticent foragers, thought to be directed at other food sources. This 'extracurricular' activity showed a high degree of temporal overlap with reconnaissance visits to the feeder. In some cases, inspection flights to the unrewarded feeder were made within the same trip to an extracurricular source, indicating that honey bees have the ability to manage at least two different time memories despite coincidence with respect to time of day. The results have major implications for understanding flower fidelity throughout the day, flower constancy within individual foraging excursions, and the sophisticated cognitive management of spatiotemporal memories in honey bees. PMID:23197093

Wagner, Ashley E; Van Nest, Byron N; Hobbs, Caddy N; Moore, Darrell

2012-11-29

357

On-farm Assessment of Forage Yields and Silage Quality of Intercropped Drought Tolerant Cereal and Legume Forage Crops (R7010)  

Microsoft Academic Search

It was concluded that intercropping cereals and legumes for silage produced high yields of good quality silage that were sufficient to supplement two cows during the dry season. The simple technology of ensiling in bags was successfully tested under farm conditions. Farmers showed confidence in the technology through nearly doubling the area planted to forage in just two years. Forage

Owen Mhere; Barbara V Maasdorp; Marion Titterton; Sylvestor M Dube; Geoffrey Heinrich; Mt Pleasant; P O Kezi

358

Mineral concentrations of forages and soils in Benue State, Nigeria. I. Macrominerals and forage in vitro organic matter digestibility and crude protein concentrations  

Microsoft Academic Search

Macromineral composition of different forage species and soils and forage in vitro organic matter digestibility (IVOMD) and crude protein concentrations in three agricultural zones of Benue State were studied. The zones consisted of Tiv zone (Zone A), Igala zone (Zone B), and Idoma zone (Zone C), each of which was made up of three sites. Site I was Fulani cattle

P. O. Ogebe; J. A. Ayoade; L. R. McDowell; N. S. Wilkinson; F. G. Martin

1995-01-01

359

Small is profitable: No support for the optimal foraging theory in sea stars Asterias rubens foraging on the blue edible mussel Mytilus edulis  

NASA Astrophysics Data System (ADS)

Doubt has been shed recently on the most popular optimal foraging theory stating that predators should maximize prey profitability, i.e., select that prey item that contains the highest energy content per handling time. We hypothesized that sea stars do not forage on blue mussels according to the classical optimal foraging theory but are actively avoiding damage that may be caused by e.g. capture of foraging on too-strong mussel shells, hence the sea stars will have a stronger preference for mussels that are smaller than the most profitable ones. Here we present experimental evidence of the sea star Asterias rubens as a predator that indeed chooses much smaller blue mussels Mytilus edulis to forage on than the most profitable ones. Hence this study does not support the optimal foraging theory. There may be other constraints involved in foraging than just optimizing energy intake, for example predators may also be concerned with preventing potential loss or damage of their foraging instruments.

Hummel, Christiaan; Honkoop, Pieter; van der Meer, Jaap

2011-07-01

360

The visual fields of two ground-foraging birds, House Finches and House Sparrows, allow for simultaneous foraging and anti-predator vigilance  

Microsoft Academic Search

In birds, differences in the extent and position of the binocular visual field reflect adaptations to varying foraging strategies, and the extent of the lateral portion of the field may reflect anti-predator strategies. The goal of this study was to describe and compare the visual fields of two ground-foraging passerines, House Finch Carpodacus mexicanus and House Sparrow Passer domesticus .

ESTEBAN FERNÁNDEZ-JURICIC; MEGAN D. GALL; TRACY DOLAN; VANESSA TISDALE; GRAHAM R. MARTIN

2008-01-01

361

Root Foraging Increases Performance of the Clonal Plant Potentilla reptans in Heterogeneous Nutrient Environments  

PubMed Central

Background Plastic root-foraging responses have been widely recognized as an important strategy for plants to explore heterogeneously distributed resources. However, the benefits and costs of root foraging have received little attention. Methodology/Principal Findings In a greenhouse experiment, we grew pairs of connected ramets of 22 genotypes of the stoloniferous plant Potentilla reptans in paired pots, between which the contrast in nutrient availability was set as null, medium and high, but with the total nutrient amount kept the same. We calculated root-foraging intensity of each individual ramet pair as the difference in root mass between paired ramets divided by the total root mass. For each genotype, we then calculated root-foraging ability as the slope of the regression of root-foraging intensity against patch contrast. For all genotypes, root-foraging intensity increased with patch contrast and the total biomass and number of offspring ramets were lowest at high patch contrast. Among genotypes, root-foraging intensity was positively related to production of offspring ramets and biomass in the high patch-contrast treatment, which indicates an evolutionary benefit of root foraging in heterogeneous environments. However, we found no significant evidence that the ability of plastic foraging imposes costs under homogeneous conditions (i.e. when foraging is not needed). Conclusions/Significance Our results show that plants of P. reptans adjust their root-foraging intensity according to patch contrast. Moreover, the results show that the root foraging has an evolutionary advantage in heterogeneous environments, while costs of having the ability of plastic root foraging were absent or very small.

Wang, Zhengwen; van Kleunen, Mark; During, Heinjo J.; Werger, Marinus J. A.

2013-01-01

362

Effects of short-term variation in forage quality and forage to concentrate ratio on lactating dairy cows.  

PubMed

Within-farm variation in forage composition can be substantial and potentially costly, and it presents challenges for sampling the forage accurately. We hypothesized that day-to-day variation in forage neutral detergent fiber (FNDF) concentrations and diet variation caused by sampling error would have negative effects on production measures in lactating dairy cows. Twenty-four Holstein cows (73d in milk) were used in 8 replicated 3×3 Latin squares with 21-d periods. Treatments were (1) control (CON), (2) variable (VAR), and (3) overreacting (ORR). On average, over the 21-d period, all 3 treatments were the same [24.7% FNDF and 48.2% forage dry matter (DM) composed of 67% alfalfa silage and 33% grass silage]. The CON treatment was essentially consistent day-to-day in total forage and FNDF concentrations and proportion of alfalfa and grass silages. The VAR treatment changed daily (in a random pattern) in proportion of alfalfa and grass silages fed, which resulted in day-to-day changes in FNDF (range was 21.5 to 28%). The ORR treatment varied in a 5-d cyclic pattern in total forage and FNDF concentrations (26, 24, 28, and 21.5% FNDF). Over the 21d, ORR (25.1kg/d) had higher DM intake compared with CON (24.5kg/d) and VAR (24.3kg/d). Milk production (42.8kg/d), milk fat (3.5%), and milk protein (2.8%) were not affected by treatment; however, a treatment × day interaction was observed for milk production. Lower daily milk yields for VAR and ORR compared with CON were rare; they only followed sustained 4- and 5-d periods of feeding higher FNDF diets compared with CON. In contrast, increased daily milk yields for VAR and ORR versus CON were more frequent and followed sustained diet changes of only 2 or 3d. Lipolytic and lipogenic-related enzyme mRNA abundances in subcutaneous adipose tissue were not affected by treatment. Treatment × day interactions were observed for milk fatty acid markers of cellulolytic bacteria (iso-14:0, iso-15:0, iso-16:0) and lipolysis (18:0) and generally followed the expected response to changes in daily rations. Overall, extreme daily fluctuations in FNDF had no cumulative negative effect on production measures over a 21-d period, and daily responses to transient increases in FNDF were less than expected. PMID:23958009

Yoder, P S; St-Pierre, N R; Daniels, K M; O'Diam, K M; Weiss, W P

2013-08-16

363

A mathematical and experimental study of ant foraging trail dynamics.  

PubMed

In this article, we present a mathematical model coupled to an experimental study of ant foraging trails. Our laboratory experiments on Tetramorium caespitum do not find a strong relationship between ant densities and velocities, a common assumption in traffic modeling. Rather, we find that higher order effects play a major role in observed behavior, and our model reflects this by including inertial terms in the evolution equation. A linearization of the resulting system yields left- and right-moving waves, in agreement with laboratory measurements. The linearized system depends upon Froude numbers reflecting a ratio of the energy stored in the foraging trail to the kinetic energy of the ants. The model predicts and the measurements support the existence of two distinct phase velocities. PMID:16442564

Johnson, Katie; Rossi, Louis F

2006-01-27

364

Dredging displaces bottlenose dolphins from an urbanised foraging patch.  

PubMed

The exponential growth of the human population and its increasing industrial development often involve large scale modifications of the environment. In the marine context, coastal urbanisation and harbour expansion to accommodate the rising levels of shipping and offshore energy exploitation require dredging to modify the shoreline and sea floor. While the consequences of dredging on invertebrates and fish are relatively well documented, no study has robustly tested the effects on large marine vertebrates. We monitored the attendance of common bottlenose dolphins (Tursiops truncatus) to a recently established urbanised foraging patch, Aberdeen harbour (Scotland), and modelled the effect of dredging operations on site usage. We found that higher intensities of dredging caused the dolphins to spend less time in the harbour, despite high baseline levels of disturbance and the importance of the area as a foraging patch. PMID:23816305

Pirotta, Enrico; Laesser, Barbara Eva; Hardaker, Andrea; Riddoch, Nicholas; Marcoux, Marianne; Lusseau, David

2013-06-29

365

Diffusion dynamics of socially learned foraging techniques in squirrel monkeys.  

PubMed

Social network analyses and experimental studies of social learning have each become important domains of animal behavior research in recent years yet have remained largely separate. Here we bring them together, providing the first demonstration of how social networks may shape the diffusion of socially learned foraging techniques. One technique for opening an artificial fruit was seeded in the dominant male of a group of squirrel monkeys and an alternative technique in the dominant male of a second group. We show that the two techniques spread preferentially in the groups in which they were initially seeded and that this process was influenced by monkeys' association patterns. Eigenvector centrality predicted both the speed with which an individual would first succeed in opening the artificial fruit and the probability that they would acquire the cultural variant seeded in their group. These findings demonstrate a positive role of social networks in determining how a new foraging technique diffuses through a population. PMID:23810529

Claidière, Nicolas; Messer, Emily J E; Hoppitt, William; Whiten, Andrew

2013-06-27

366

Chemical compounds of the foraging recruitment pheromone in bumblebees  

NASA Astrophysics Data System (ADS)

When the frenzied and irregular food-recruitment dances of bumblebees were first discovered, it was thought that they might represent an evolutionary prototype to the honeybee waggle dance. It later emerged that the primary function of the bumblebee dance was the distribution of an alerting pheromone. Here, we identify the chemical compounds of the bumblebee recruitment pheromone and their behaviour effects. The presence of two monoterpenes and one sesquiterpene (eucalyptol, ocimene and farnesol) in the nest airspace and in the tergal glands increases strongly during foraging. Of these, eucalyptol has the strongest recruitment effect when a bee nest is experimentally exposed to it. Since honeybees use terpenes for marking food sources rather than recruiting foragers inside the nest, this suggests independent evolutionary roots of food recruitment in these two groups of bees.

Granero, Angeles Mena; Sanz, José M. Guerra; Gonzalez, Francisco J. Egea; Vidal, José L. Martinez; Dornhaus, Anna; Ghani, Junaid; Serrano, Ana Roldán; Chittka, Lars

2005-08-01

367

Extrafloral nectar content alters foraging preferences of a predatory ant.  

PubMed

We tested whether the carbohydrate and amino acid content of extrafloral nectar affected prey choice by a predatory ant. Fire ants, Solenopsis invicta, were provided with artificial nectar that varied in the presence of carbohydrates and amino acids and were then provided with two prey items that differed in nutritional content, female and male crickets. Colonies of fire ants provided with carbohydrate supplements consumed less of the female crickets and frequently did not consume the high-lipid ovaries of female crickets. Colonies of fire ants provided with amino acid supplements consumed less of the male crickets. While a number of studies have shown that the presence of extrafloral nectar or honeydew can affect ant foraging activity, these results suggest that the nutritional composition of extrafloral nectar is also important and can affect subsequent prey choice by predatory ants. Our results suggest that, by altering the composition of extrafloral nectar, plants could manipulate the prey preferences of ants foraging on them. PMID:19864270

Wilder, Shawn M; Eubanks, Micky D

2009-10-28

368

Actions speak louder than words in socially foraging human groups.  

PubMed

SOCIAL FORAGING IN HUMANS HAS A DEEP EVOLUTIONARY HISTORY: early hominids searched for dispersed food sources in a patchy, uncertain environment. A fundamental assumption is that social foragers benefit by exchanging information about food sources, in order to make collective decisions based on pooled information. We conducted the first experimental test of this assumption, and showed that, as predicted, communication significantly enhanced group performance. A further, unexpected result was that physical communication through gesturing, rather than verbal communication, appeared to play a crucial role in the early stages of group interaction, facilitating consensus decision making by groups.  The importance of gestures in human interactions may therefore be underestimated, and this has important implications for modern human societies, where communications are becoming increasingly dominated by virtual modes of communication that preclude the use of gestures.  PMID:22446547

Sumner, Seirian; King, Andrew J

2011-11-01

369

Physical barrier to reduce WP mortalities of foraging waterfowl  

SciTech Connect

White phosphorus (WP) has been identified as the cause of mortality to certain species of water-fowl at Eagle River Flats, a tidal marsh in Alaska, used as an ordinance impact area by the US Army. A blend of calcium bentonite/organo clays, gravel, and binding polymers was tested for effectiveness as a barrier to reduce duck foraging and mortality. Following the application of the barrier to one of two contaminated ponds, the authors observed greater duck foraging and higher mortality in the untreated pond and no mortality in the treated pond after a year of tidal inundations and ice effects. Emergent vegetation recovered within a year of treatment. WP levels in the barrier were less than the method limit of detection, indicating no migration of WP into the materials. Barrier thickness remained relatively stable over a period of 4 years, and vegetation was found to be important in stabilizing the barrier material.

Pochop, P.A.; Cummings, J.L.; Yoder, C.A.; Gossweiler, W.A.

2000-02-01

370

Intelligent Feature Selection by Bacterial Foraging Algorithm and Information Theory  

Microsoft Academic Search

\\u000a In this paper, an intelligent feature selection by bacterial foraging algorithm and mutual information is proposed. Feature\\u000a selection is an important issue in the pattern classification problem. Particularly, in the case of classifying with a large\\u000a number of features or variables, the accuracy and computational time of the classifier can be improved by using the relevant\\u000a feature subset to remove

Jae Hoon Cho; Dong Hwa Kim

371

Foraging ecology of the California gnatcatcher deduced from fecal samples  

Microsoft Academic Search

The California gnatcatcher is a threatened species essentially restricted to coastal sage scrub habitat in southern California.\\u000a Its distribution and population dynamics have been studied intensely, but little is known about its diet. We identified arthropod\\u000a fragments in 33 fecal samples of the California gnatcatcher to gain insight into its foraging ecology and diet. Fecal samples\\u000a were collected from adult

Jutta C. Burger; Michael A. Patten; John T. Rotenberry; Richard A. Redak

1999-01-01

372

[Selection of foraging tactics in leaf Warblers (phylloscopus)].  

PubMed

Aviary observations revealed particularities of foraging behavior in seven species of leaf warblers of the genus Phylloscopus, which sympatrically inhabit the middle-taiga Yenisei. The differences consist in the ratio of the tactics of each type, including the flight, frequency of using them, and selectivity with respect to maneuvers. The obtained results are discussed from the point of view of particularities of the external morphology of the species. PMID:21789995

Batova, O N

373

Do house mice use UV cues when foraging?  

Microsoft Academic Search

Research on the behavioural ecology of ultraviolet (UV-A, wavelengths of 320–400 nm, hereafter: UV) sensitivity in terrestrial\\u000a vertebrates has mainly focused on sexual signalling and foraging in birds and reptiles, whereas the fact that some rodents\\u000a are also sensitive to UV light has been somewhat ignored. Here, we present the results of two behavioural experiments, which\\u000a tested whether rodents use UV

Johanna Honkavaara; Helena Åberg; Jussi Viitala

2008-01-01

374

Sexy birds are superior at solving a foraging problem.  

PubMed

Yellow, red or orange carotenoid-based colorations in male birds are often a signal to prospecting females about body condition, health status and ability to find food. However, this general 'ability to find food' has never been defined. Here we show that more brightly ornamented individuals may also be more efficient when foraging in novel situations. The results highlight the fact that evolution may have provided females tools to evaluate cognitive abilities of the males. PMID:21450725

Mateos-Gonzalez, Fernando; Quesada, Javier; Senar, Juan Carlos

2011-03-30

375

Foraging parameters of gentoo penguins Pygoscelis papua at Marion Island  

Microsoft Academic Search

We measured the foraging parameters of breeding gentoo penguins Pygoscelis papua at sub-Antarctic Marion Island. Mean swimming speed was 7.9 km h-1. Penguins spent on average 8.1 h away from the colony if they returned on the same day they left and 23.7 h away if they remained at sea overnight. Sixteen percent of the total time away at sea

N. J. Adams; M.-P. Wilson

1987-01-01

376

Central-place seed foraging and vegetation patterns  

Microsoft Academic Search

We investigate how central-place seed foragers with a nest in the proximity of one or more seed sources determine the formation of different vegetation patterns. In particular, we discuss the ecological conditions that lead to the formation of hump-shaped (Janzen–Connell) patterns in a two-dimensional landscape. Our analysis shows that central-place predation can generate Janzen–Connell patterns even if predators’ movement strategies

Lorenzo Mari; Marino Gatto; Renato Casagrandi

2009-01-01

377

Size variation and foraging rate in bumblebees ( Bombus terrestris )  

Microsoft Academic Search

Summary: Size polymorphism is an important life history trait in bumblebees with strong impact on individual behavior and colony organization. Within a colony larger workers tend to serve as foragers, while smaller workers fulfill in-hive tasks. It is often assumed that size-dependent division of labor relates to differences in task performance. In this study we examined size-dependent interindividual variability in

J. Spaethe; A. Weidenmüller

2002-01-01

378

Bee foraging in uncertain environments using predictive hebbian learning  

Microsoft Academic Search

RECENT work has identified a neuron with widespread projections to odour processing regions of the honeybee brain whose activity represents the reward value of gustatory stimuli1,2. We have constructed a model of bee foraging in uncertain environments based on this type of neuron and a predictive form of hebbian synaptic plasticity. The model uses visual input from a simulated three-dimensional

P. Read Montague; Peter Dayan; Christophe Person; Terrence J. Sejnowski

1995-01-01

379

Optimal foraging: food patch depletion by ruddy ducks  

Microsoft Academic Search

I studied the foraging behavior of ruddy ducks (Oxyura jamaicensis) feeding on patchily distributed prey in a large (5-m long, 2-m wide, and up to 2-m deep) aquarium. The substrate consisted of a 4x4 array of wooden trays (1.0-m long, 0.5-m wide, and 0.1-m deep) which contained 6 cm of sand. Any tray could be removed from the aquarium and

Michael W. Tome

1988-01-01

380

Effects of recent experience on foraging in tephritid fruit flies  

Microsoft Academic Search

In field-cage studies, we investigated how the foraging behavior of tephritid fruit flies is modified by experience immediately prior to release on host plants. We observed females of a relatively monophagous species,Rhagoletis mendax (blueberry maggot fly), an oligophagous species,Rhagoletis pomomella (apple maggot fly), and a polyphagous species,Ceratitis capitata (Mediterranean fruit fly). Just prior to release on a host plant, the

A. L. Averill; R. J. Prokopy; M. M. Sylvia; P. P. Connor; T. T. Y. Wong

1996-01-01

381

Sexy birds are superior at solving a foraging problem  

PubMed Central

Yellow, red or orange carotenoid-based colorations in male birds are often a signal to prospecting females about body condition, health status and ability to find food. However, this general ‘ability to find food’ has never been defined. Here we show that more brightly ornamented individuals may also be more efficient when foraging in novel situations. The results highlight the fact that evolution may have provided females tools to evaluate cognitive abilities of the males.

Mateos-Gonzalez, Fernando; Quesada, Javier; Senar, Juan Carlos

2011-01-01

382

Social calls coordinate foraging in greater spear-nosed bats  

Microsoft Academic Search

The function of social calls emitted by foraging bats has received little study. Here we use observations of free-ranging greater spear-nosed bats,Phyllostomus hastatus, and field playbacks to determine whether audible, broad-band ‘screech’ calls attract mates, warn conspecifics or influence access to food. Five lines of evidence suggest that screech calls enable adult females from the same roosting group to fly

GERALD S. WILKINSON; JANETTE WENRICK BOUGHMAN

1998-01-01

383

Variations of foraging tactics in a water bug, Diplonychus indicus  

Microsoft Academic Search

The predatory behaviour ofDiplonychus indicus Venk. & Rao (Heteroptera: Belostomatidae), a tropical water bug, appeared to be highly versatile. Male adultD. indicus alternated from active foraging to ambushing during the same observation. The predatory movements described here were divided\\u000a into 7 different categories. Five include ambushing and no active search: simple capture, strike, lunge and strikes following\\u000a a preliminary vertical

Ann Cloarec; CNRS UA

1989-01-01

384

Prey size selection and distance estimation in foraging adult dragonflies  

Microsoft Academic Search

To determine whether perching dragonflies visually assess the distance to potential prey items, we presented artificial prey,\\u000a glass beads suspended from fine wires, to perching dragonflies in the field. We videotaped the responses of freely foraging\\u000a dragonflies (Libellula luctuosa and Sympetrum vicinum—Odonata, suborder Anisoptera) to beads ranging from 0.5 mm to 8 mm in diameter, recording whether or not the dragonflies\\u000a took

R. M. Olberg; A. H. Worthington; J. L. Fox; C. E. Bessette; M. P. Loosemore

2005-01-01

385

Symmetry breaking in collective honeybee foraging: a simulation study  

Microsoft Academic Search

Symmetry breaking is the phenomenon that the numbers of foragers exploiting two equally profitable food sources will diverge. This\\u000aphenomenon has been investigated in ants [1,4,5], but hardly in honeybees. It is even not clear whether in honeybees symmetry breaking\\u000acan occur [3, p.190]. We present results of an individual-oriented simulation model showing that under specific circumstances symmetry\\u000abreaking in

Han de Vries; Jacobus C. Biesmeijer

2002-01-01

386

Sensory allometry, foraging task specialization and resource exploitation in honeybees  

Microsoft Academic Search

Insect societies are important models for evolutionary biology and sociobiology. The complexity of some eusocial insect societies\\u000a appears to arise from self-organized task allocation and group cohesion. One of the best-supported models explaining self-organized\\u000a task allocation in social insects is the response threshold model, which predicts specialization due to inter-individual variability\\u000a in sensitivity to task-associated stimuli. The model explains foraging

Andre J. Riveros; Wulfila Gronenberg

2010-01-01

387

Resource heterogeneity and patterns of movement in foraging bumblebees  

Microsoft Academic Search

Differences in the foraging behavior of B. terricola workers on white clover, Trifolium repens, were examined on previously unvisited (filled) and depleted flowers, and as a function of flower-head density.1.The number of florets visited per unit time was independent of flower head density from 20 to at least 290 heads\\/m2, in part because the bees utilized more florets per head

Bernd Heinrich

1979-01-01

388

Evolutionary and anthropological perspectives on optimal foraging in obesogenic environments  

Microsoft Academic Search

The nutrition transition has created an obesogenic environment resulting in a growing obesity pandemic. An optimal foraging approach provides cost\\/benefit models of cognitive, behavioral and physiological strategies that illuminate the causes of caloric surfeit and consequent obesity in current environments of abundant food cues; easy-access and reliable food patches; low processing costs and enormous variety of energy-dense foods. Experimental and

Leslie Sue Lieberman

2006-01-01

389

Three Foraging Models Comprised of Ants with Different Pheromone Sensitivities  

Microsoft Academic Search

\\u000a An ant colony shows collective behavior through signal patterns formed by individual ants communicating among themselves who\\u000a behave according to local information. First, in this paper I devise a method for designing ant colony models that describes\\u000a both the formation mechanism of signal patterns and the regulation mechanism of task allocation. Next, using the above method,\\u000a I design three foraging

Mari Nakamura

2005-01-01

390

Diving Patterns and Foraging Locations of Female Northern Fur Seals  

Microsoft Academic Search

Nine lactating north­ ern fur seals Callo7'hinus ursinus from St. Paul Island. Alaska, were in­ strumented with time-depth record­ ers and head-mounted radio trans­ mitters in July and August 1985. Seven females were subsequently located at least once while at sea. Diving patterns obtained from fe­ males' time-depth recorders were then associated with their foraging locations. Generally two diving pat­

Michael E. Goebel; John L. Bengtson

391

Foraging and farming as niche construction: stable and unstable adaptations.  

PubMed

All forager (or hunter-gatherer) societies construct niches, many of them actively by the concentration of wild plants into useful stands, small-scale cultivation, burning of natural vegetation to encourage useful species, and various forms of hunting, collectively termed 'low-level food production'. Many such niches are stable and can continue indefinitely, because forager populations are usually stable. Some are unstable, but these usually transform into other foraging niches, not geographically expansive farming niches. The Epipalaeolithic (final hunter-gatherer) niche in the Near East was complex but stable, with a relatively high population density, until destabilized by an abrupt climatic change. The niche was unintentionally transformed into an agricultural one, due to chance genetic and behavioural attributes of some wild plant and animal species. The agricultural niche could be exported with modifications over much of the Old World. This was driven by massive population increase and had huge impacts on local people, animals and plants wherever the farming niche was carried. Farming niches in some areas may temporarily come close to stability, but the history of the last 11,000 years does not suggest that agriculture is an effective strategy for achieving demographic and political stability in the world's farming populations. PMID:21320899

Rowley-Conwy, Peter; Layton, Robert

2011-03-27

392

Future Climate Impacts on Bay Area Rangeland Forage Production  

NASA Astrophysics Data System (ADS)

The San Francisco Bay Area is a highly heterogeneous region in climate, topography, and habitats, as well as in its political and economic interests. Downscaled projections of global climate models enable the fine-scale analysis necessary for conservation and climate adaptation planning across such a diverse area. Successful conservation strategies must consider various current and future competing demands for the land, and should pay special attention to the dominant non-urban land-use in the Bay Area: livestock grazing. Maintaining the viability of rangelands provides an economic incentive for the preservation of open space. Climate models suggest that forage production in Bay Area rangelands may be enhanced by future conditions in most years, at least in terms of peak standing crop. However, the timing of production is as important as its peak, and altered precipitation patterns could mean delayed germination, resulting in shorter growing seasons. An increase in the frequency of extremely dry years also increases the uncertainty of forage availability. These shifts in forage production will affect the economic viability of rangelands in the Bay Area.

Chaplin-Kramer, R.

2011-12-01

393

Swimming speed and foraging strategies of northern elephant seals  

NASA Astrophysics Data System (ADS)

We investigated swimming speed, a key variable in both the management of oxygen stores and foraging strategies, and its relationship to diving behaviour in northern elephant seals , Mirounga angustirostris. Swimming speed significantly reduced the dive duration and time at depth for presumed foraging dives, but increased with dive depth. This suggests that the extended duration of deep dives is made possible by physiological adjustments and not by changes in swimming speed or effort. Swimming speeds were similar across sex and age classes despite different predicted minimum cost of transport speeds. All seals exhibited characteristic dive shapes and swimming speed patterns that support their putative functions, but two-dimensional dive shapes and swimming angles varied between sexes and age classes. Mean dive angles on descent were markedly shallow, suggesting use of negative buoyancy to cover horizontal distance while diving. Buoyancy also appeared to affect two-dimensional dive shapes and ability to use extended gliding behaviours between surface and deep foraging zones. Significant differences in diving behaviour between sexes and between young and adult females were evident for various phases of the dive cycle, potentially resulting from physical constraints or differences in dive functionality.

Hassrick, Jason L.; Crocker, Daniel E.; Zeno, Ramona L.; Blackwell, Susanna B.; Costa, Daniel P.; Le Boeuf, Burney J.

2007-02-01

394

Piping Plover brood foraging ecology on New York barrier islands  

USGS Publications Warehouse

Effective management of piping plover (Charadrius melodus) populations requires knowledge of the habitats that foster successful reproduction. We studied piping plover chick foraging ecology and survival on the central barrier islands of Long Island, New York, 1992 and 1993. Within the 90-km study area, all 1-km beach segments with ephemeral pools or bay tidal flats were used for nesting and brood rearing, whereas <50% of beach segments without these habitats were used. On beach segments with ephemeral pools, broods preferred ephemeral pools to ocean intertidal zone, wrack, backshore, open vegetation, and interdune habitat. Indices of terrestrial arthropod abundance and foraging rates were greater in ephemeral pools than in other habitats. In 1992, chick survival was higher on beach segments with ephemeral pools than on segments without ephemeral pools. On beach segments with bay tidal flats, broods preferred bay tidal flats and wrack to ocean intertidal zone, backshore, and open vegetation habitats. Foraging rates in bay tidal flats were similar to those in ephemeral pools and greater than in open vegetation, wrack, and backshore habitats. On beach segments without ephemeral pools and bay tidal flats, broods preferred wrack to all other habitats, and open vegetation was second most preferred. To assist in the recovery of the piping plover, land-use planners should avoid beach management practices (e.g., beach filling, dune building, renourishment) that typically inhibit natural renewal of ephemeral pools, bay tidal flats, and open vegetation habitats.

Elias, S.P.; Fraser, J.D.; Buckley, P.A.

2000-01-01

395

The FGLamide-allatostatins influence foraging behavior in Drosophila melanogaster.  

PubMed

Allatostatins (ASTs) are multifunctional neuropeptides that generally act in an inhibitory fashion. ASTs were identified as inhibitors of juvenile hormone biosynthesis. Juvenile hormone regulates insect metamorphosis, reproduction, food intake, growth, and development. Drosophila melanogaster RNAi lines of PheGlyLeu-amide-ASTs (FGLa/ASTs) and their cognate receptor, Dar-1, were used to characterize roles these neuropeptides and their respective receptor may play in behavior and physiology. Dar-1 and FGLa/AST RNAi lines showed a significant reduction in larval foraging in the presence of food. The larval foraging defect is not observed in the absence of food. These RNAi lines have decreased for transcript levels which encodes cGMP- dependent protein kinase. A reduction in the for transcript is known to be associated with a naturally occurring allelic variation that creates a sitter phenotype in contrast to the rover phenotype which is caused by a for allele associated with increased for activity. The sitting phenotype of FGLa/AST and Dar-1 RNAi lines is similar to the phenotype of a deletion mutant of an AST/galanin-like receptor (NPR-9) in Caenorhabditis elegans. Associated with the foraging defect in C. elegans npr-9 mutants is accumulation of intestinal lipid. Lipid accumulation was not a phenotype associated with the FGLa/AST and Dar-1 RNAi lines. PMID:22558326

Wang, Christine; Chin-Sang, Ian; Bendena, William G

2012-04-27

396

COMMUNICATION: Stochastic resonance and the evolution of Daphnia foraging strategy  

NASA Astrophysics Data System (ADS)

Search strategies are currently of great interest, with reports on foraging ranging from albatrosses and spider monkeys to microzooplankton. Here, we investigate the role of noise in optimizing search strategies. We focus on the zooplankton Daphnia, which move in successive sequences consisting of a hop, a pause and a turn through an angle. Recent experiments have shown that their turning angle distributions (TADs) and underlying noise intensities are similar across species and age groups, suggesting an evolutionary origin of this internal noise. We explore this hypothesis further with a digital simulation (EVO) based solely on the three central Darwinian themes: inheritability, variability and survivability. Separate simulations utilizing stochastic resonance (SR) indicate that foraging success, and hence fitness, is maximized at an optimum TAD noise intensity, which is represented by the distribution's characteristic width, ?. In both the EVO and SR simulations, foraging success is the criterion, and the results are the predicted characteristic widths of the TADs that maximize success. Our results are twofold: (1) the evolving characteristic widths achieve stasis after many generations; (2) as a hop length parameter is changed, variations in the evolved widths generated by EVO parallel those predicted by SR. These findings provide support for the hypotheses that (1) ? is an evolved quantity and that (2) SR plays a role in evolution.

Dees, Nathan D.; Bahar, Sonya; Moss, Frank

2008-12-01

397

Stochastic resonance and the evolution of Daphnia foraging strategy.  

PubMed

Search strategies are currently of great interest, with reports on foraging ranging from albatrosses and spider monkeys to microzooplankton. Here, we investigate the role of noise in optimizing search strategies. We focus on the zooplankton Daphnia, which move in successive sequences consisting of a hop, a pause and a turn through an angle. Recent experiments have shown that their turning angle distributions (TADs) and underlying noise intensities are similar across species and age groups, suggesting an evolutionary origin of this internal noise. We explore this hypothesis further with a digital simulation (EVO) based solely on the three central Darwinian themes: inheritability, variability and survivability. Separate simulations utilizing stochastic resonance (SR) indicate that foraging success, and hence fitness, is maximized at an optimum TAD noise intensity, which is represented by the distribution's characteristic width, sigma. In both the EVO and SR simulations, foraging success is the criterion, and the results are the predicted characteristic widths of the TADs that maximize success. Our results are twofold: (1) the evolving characteristic widths achieve stasis after many generations; (2) as a hop length parameter is changed, variations in the evolved widths generated by EVO parallel those predicted by SR. These findings provide support for the hypotheses that (1) sigma is an evolved quantity and that (2) SR plays a role in evolution. PMID:19029598

Dees, Nathan D; Bahar, Sonya; Moss, Frank

2008-11-24

398

Transcriptional Response to Foraging Experience in the Honey Bee Mushroom Bodies  

PubMed Central

Enriched environmental conditions induce neuroanatomical plasticity in a variety of vertebrate and invertebrate species. We explored the molecular processes associated with experience-induced plasticity, using naturally occurring foraging behavior in adult worker honey bees (Apis mellifera). In honey bees, the mushroom bodies exhibit neuroanatomical plasticity that is dependent on accumulated foraging experience. To investigate molecular processes associated with foraging experience, we performed a time-course microarray study to examine gene expression changes in the mushroom bodies as a function of days foraged. We found almost 500 genes that were regulated by duration of foraging experience. Bioinformatic analyses of these genes suggest that foraging experience is associated with multiple molecular processes in the mushroom bodies, including some that may contribute directly to neuropil growth, and others that could potentially protect the brain from the effects of aging and physiological stress.

Lutz, Claudia C.; Rodriguez-Zas, Sandra L.; Fahrbach, S.E.; Robinson, Gene E.

2011-01-01

399

Group-foraging is not associated with longevity in North American birds.  

PubMed

Group-foraging is common in many animal taxa and is thought to offer protection against predators and greater foraging efficiency. Such benefits may have driven evolutionary transitions from solitary to group-foraging. Greater protection against predators and greater access to resources should reduce extrinsic sources of mortality and thus select for higher longevity according to life-history theory. I assessed the association between group-foraging and longevity in a sample of 421 North American birds. Taking into account known correlates of longevity, such as age at first reproduction and body mass, foraging group size was not correlated with maximum longevity, with and without phylogenetic correction. However, longevity increased with body mass in non-passerine birds. The results suggest that the hypothesized changes in predation risk with group size may not correlate with mortality rate in foraging birds. PMID:19776065

Beauchamp, Guy

2009-09-23

400

Food foraging of honey bees in a microwave field (2. 45 GHz CW)  

SciTech Connect

Honey bees were trained to fly 400 m from their colony to an indoor laboratory foraging arena exposed to 2.45 GHz continuous wave microwaves at 5 power densities (0, 5, 10, 20, and 40 mW/cm/sup 2/). Foraging behavior did not differ from controls foraging within an unexposed sham arena in (1) number of round trips completed during a 3-h exposure session, (2) round trip time between the colony and the foraging arena, and (3) the length of time required to navigate the illuminated foraging arena. This study indicates that honey bees would not be adversely affected by foraging within a similar microwave field that would exist in future receiving antennae for the proposed solar power satellite energy transmission system in which power levels are expected to range from 23 mW/cm/sup 2/ at the antenna center to 1 mW/cm/sup 2/ at the edge.

Gary, N.E.; Westerdahl, B.B.

1982-02-15

401

Benefits of heterospecific foraging by the Caribbean wrasse, Halichoeres garnoti (Pisces: Labridae)  

Microsoft Academic Search

Synopsis  Terminal-phase yellowhead wrasses, Halichoeres garnoti, foraged alone or in association with foraging goatfish, Pseudupeneus maculatus and Mulloides martinicus. Whereas H. garnoti did not dig for benthic infauna, the goatfish foraged almost exclusively on and in sand substrata. Wrasses in the company\\u000a of goatfish made significantly more strikes on sand substrata than did solitary wrasses, although there were no significant\\u000a differences

Richard B. Aronsonr; S. Laurie Sanderson

1987-01-01

402

Hunger effects on foraging responses to perceptual cues in immature and adult wolf spiders (Lycosidae)  

Microsoft Academic Search

The wolf spider,Schizocosa ocreata(Hentz), varies foraging patch residence time in the presence of different sensory cues from prey, even without food rewards. This study examines the influence and interaction of hunger state, age and sex on the use of different types of sensory information to determine foraging patch sampling duration. In a series of two-chambered artificial foraging patches, I tested

MATTHEW H. PERSONS

1999-01-01

403

Spatial working memory for clustered and linear configurations of sites in a virtual reality foraging task.  

PubMed

Two experiments using an immersive virtual reality foraging environment determined the spatial strategies spontaneously deployed by people in a foraging task and the effects on immediate serial recall of trajectories though the foraging space, which could conform or violate specific organisational constraints. People benefitted from the use of organised search patterns when attempting to monitor their travel though either a clustered "patchy" space or a matrix of locations. The results are discussed within a comparative framework. PMID:22802028

De Lillo, Carlo; James, Frances C

2012-08-01

404

Mapping quantitative trait loci controlling variation in forage quality traits in barley  

Microsoft Academic Search

Barley forage quality has a direct relationship to animal performance, but forage quality traits are often neglected or not\\u000a accessible to the plant breeders. Doubled haploid lines (145) from the cross Steptoe × Morex were grown in 2 years of trails\\u000a under irrigated conditions to evaluate the variation in forage quality characteristics, identify quantitative trait loci (QTL)\\u000a for these traits and determine if

Lisa Surber; Hussein Abdel-Haleem; Jack Martin; Pat Hensleigh; Dennis Cash; Jan Bowman; Tom Blake

2011-01-01

405

Prey selection and foraging performance of breeding Great Tits Parus major in relation to food availability  

Microsoft Academic Search

Naef-Daenzer, L., Naef-Daenzer, B. and Nager, R. G. 2000. Prey selection and foraging performance of breeding Great Tits Parus major in relation to food availability. - J. Avian Biol. 31: 206-214. We studied the nestling diet and the foraging performance of Great Tits in relation to prey abundance in the field. Numerous experimental studies present data on foraging decisions in

Luzia Naef-Daenzer; Beat Naef-Daenzer; Ruedi G. Nager

2000-01-01

406

Chewing behaviour in the domestic donkey ( Equus asinus) fed fibrous forage  

Microsoft Academic Search

A study was conducted to investigate chewing activity in domestic donkeys eating long-stem, high-fiber forage. Five donkeys (body weight 198±15 kg) were fed 2 types of forage containing equal amounts of fiber (65% neutral detergent fiber: NDF) at two levels of crude protein (CP). Forage consumed was either a mixed legume\\/orchard grass hay (CP 13.7%) or a grass hay (CP

P. J Mueller; P Protos; K. A Houpt; P. J Van Soest

1998-01-01

407

Foraging for animal prey by outdoor groups of Geoffroy’s marmosets (Callithrix geoffroyi)  

Microsoft Academic Search

I studied animal prey foraging by three outdoor groups of Geoffroy’s marmosets, Callithrix geoffroyi, over the course of two\\u000a summers (June–August 1994; August–September, 1995. Marmosets are highly motivated to forage for animal prey, as demonstrated\\u000a by the amount of time spent foraging for insects and small vertebrates even in the presence of provisioned, high-quality food.\\u000a Like their wild congeners, the

Nancy G. Caine

1996-01-01

408

Benefits to satellite members in mixed-species foraging groups: an experimental analysis  

Microsoft Academic Search

Hypotheses proposed to explain the formation of mixed-species foraging groups have focused on both foraging and antipredation benefits. Mixed-species flocks of bark-foraging birds form during the winter in the eastern deciduous forests of North America. These flocks are composed of two parid nuclear species, tufted titmice,Baeolophus bicolor, and either Carolina or black-capped chickadees,Poecile carolinensisorP.atricapillus, and several satellite species including downy

ANDREW S DOLBY; THOMAS C GRUBB JR

1998-01-01

409

Partial Replacement of Forage with Nonforage Fiber Sources in Lactating Cow Diets. I. Performance and Health  

Microsoft Academic Search

Seventy-eight Holsteins were fed for 112 d to evaluate performance and health responses to diets varying in source and concentration of fiber. Three diets based on different carbohydrate feeding strategies were formu- lated. These diets contained low concentrations of for- age and neutral detergent fiber (NDF) (12.6% forage NDF, 19.5% total NDF), adequate NDF and forage (20% forage NDF, 24.8%

M. N. Pereira; E. F. Garrett; G. R. Oetzel; L. E. Armentanto

1999-01-01

410

Foraging Response of Turkish Honey Bee Subspecies to Flower Color Choices and Reward Consistency  

Microsoft Academic Search

Foraging behavior of Apis mellifera caucasica, A.m. carnica and A.m. syriaca in Turkey was studied for intrinsic subspecies-based differences. Models of forager flower-color fidelity, risk sensitive\\u000a behavior and maximizing net gain were tested. Foragers were presented artificial flower patches containing blue, white and\\u000a yellow flowers. Some bees of each subspecies showed high fidelity to yellow flowers, while others favored blue

Ibrahim Cakmak; Daniel S. Song; T. Andrew Mixson; Eduardo Serrano; Meredith L. Clement; Amy Savitski; Ge’Andra Johnson; Tugrul Giray; Charles I. Abramson; John F. Barthell; Harrington Wells

2010-01-01

411

DEVELOPMENT OF AN AUTOMATED SYSTEM FOR SAMPLING CROP MATERIAL FROM A FORAGE HARVESTER  

Microsoft Academic Search

A modular, computer-controlled sampling system was developed to directly sample chopped forage material from a forage harvester spout. Pneumatic cylinders powered a deflector flap to redirect crop material from the spout. A hydraulic cylinder compressed deflected forage material into 35.6-cm long, 10.2-cm diameter PVC pipes, which served as miniature test silos. Timing of the pneumatic and hydraulic actuators was controlled

D. R. Buckmaster

412

Nutritive quality and morphological development under partial shade of some forage species with agroforestry potential  

Microsoft Academic Search

The shade environment produced in agroforestry practices affects the morphology, anatomy and chemical composition of intercropped\\u000a forages and, therefore, may affect forage quality. During the summer-fall growing season of 1994 and 1995, 30 forage cultivars\\u000a were grown in 7.6 L (two gallon) pots in full sun, 50%, and 80% shade created by placing shade cloth over a greenhouse frame.\\u000a Fifteen

C. H. Lin; M. L. McGraw; M. F. George; H. E. Garrett

2001-01-01

413

RED-COCKADED WOODPECKER FORAGING BEHAVIOR IN RELATION TO MIDSTORY VEGETATION  

Microsoft Academic Search

Red-cockaded Woodpeckers (P&ides borealis) nest and forage in pine-dominated forests. Research indicates that substantial hardwood midstory encroachment is detrimental to Red-cockaded Wood- pecker populations, although the exact mechanisms are unknown. We examined foraging behavior in relation to midstory between August 1989 and February 1990. Red-cockaded Woodpeckers foraged at greater heights in areas of taller and denser midstory in the loblolly-shortleaf

D. CRAIG RUDOLPH; RICHARD N. CONNER; RICHARD R. SCHAEFER

2002-01-01

414

Nectar robbing, forager efficiency and seed set: Bumblebees foraging on the self incompatible plant Linaria vulgaris (Scrophulariaceae)  

NASA Astrophysics Data System (ADS)

In southern England, Linaria vulgaris (common yellow toadflax) suffers from high rates of nectar robbery by bumblebees. In a wild population of L. vulgaris we found that 96 % of open flowers were robbed. Five species of bumblebee were observed foraging on these flowers, although short-tongued species ( Bombus lapidarius, B. lucorum and B. terrestris) robbed nectar whilst longer-tongued ones behaved as legitimate pollinators ( B. hortorum and B. pascuorum). Nectar rewards were highly variable; on average there was less nectar in robbed than in unrobbed flowers, but this difference was not statistically significant. The proportion of flowers containing no nectar was significantly higher for robbed flowers compared with unrobbed flowers. Secondary robbers and legitimate pollinators had similar handling times on flowers and, assuming they select flowers at random to forage on, received approximately the same nectar profit per minute, largely because most flowers had been robbed. There was no significant difference in the number of seeds in pods of robbed flowers and in pods of flowers that were artificially protected against robbing. However, more of the robbed flowers set at least some seed than the unrobbed flowers, possibly as a consequence of the experimental manipulation. We suggest that nectar robbing has little effect on plant fecundity because legitimate foragers are present in the population, and that seed predation and seed abortion after fertilization may be more important factors in limiting seed production in this species.

Stout, Jane C.; Allen, John A.; Goulson, Dave

2000-07-01

415

The dynamics of foraging trails in the tropical arboreal ant Cephalotes goniodontus.  

PubMed

The foraging behavior of the arboreal turtle ant, Cephalotes goniodontus, was studied in the tropical dry forest of western Mexico. The ants collected mostly plant-derived food, including nectar and fluids collected from the edges of wounds on leaves, as well as caterpillar frass and lichen. Foraging trails are on small pieces of ephemeral vegetation, and persist in exactly the same place for 4-8 days, indicating that food sources may be used until they are depleted. The species is polydomous, occupying many nests which are abandoned cavities or ends of broken branches in dead wood. Foraging trails extend from trees with nests to trees with food sources. Observations of marked individuals show that each trail is travelled by a distinct group of foragers. This makes the entire foraging circuit more resilient if a path becomes impassable, since foraging in one trail can continue while a different group of ants forms a new trail. The colony's trails move around the forest from month to month; from one year to the next, only one colony out of five was found in the same location. There is continual searching in the vicinity of trails: ants recruited to bait within 3 bifurcations of a main foraging trail within 4 hours. When bait was offered on one trail, to which ants recruited, foraging activity increased on a different trail, with no bait, connected to the same nest. This suggests that the allocation of foragers to different trails is regulated by interactions at the nest. PMID:23209749

Gordon, Deborah M

2012-11-28

416

Simulating secondary succession of elk forage values in a managed forest landscape, western Washington  

USGS Publications Warehouse

Modern timber management practices often influence forage production for elk (Cervus elaphus) on broad temporal and spatial scales in forested landscapes. We incorporated site-specific information on postharvesting forest succession and forage characteristics in a simulation model to evaluate past and future influences of forest management practices on forage values for elk in a commercially managed Douglas fir (Pseudotsuga menziesii, PSME)-western hemlock (Tsuga heterophylla, TSHE) forest in western Washington. We evaluated future effects of: (1) clear-cut logging 0, 20, and 40% of harvestable stands every five years; (2) thinning 20-year-old Douglas fir forests; and (3) reducing the harvesting cycle from 60 to 45 years. Reconstruction of historical patterns of vegetation succession indicated that forage values peaked in the 1960s and declined from the 1970s to the present, but recent values still were higher than may have existed in the unmanaged landscape in 1945. Increased forest harvesting rates had little short-term influence on forage trends because harvestable stands were scarce. Simulations of forest thinning also produced negligible benefits because thinning did not improve forage productivity appreciably at the stand level. Simulations of reduced harvesting cycles shortened the duration of declining forage values from approximately 30 to 15 years. We concluded that simulation models are useful tools for examining landscape responses of forage production to forest management strategies, but the options examined provided little potential for improving elk forages in the immediate future.

Jenkins, Kurt J.; Starkey, Edward E.

1996-01-01

417

Daily foraging pattern and proteinaceous food preferences of Solenopsis geminata (Fabricius) (Hymenoptera:Formicidae).  

PubMed

A field study on foraging activity and proteinacous food preference was performed on the tropical fire ant (Solenopsis geminata) (Fabricius) at the School of Biological Sciences and Desasiswa Bakti Permai, Universiti Sains Malaysia (USM), Penang. Foraging activity studies of 4 colonies of S. geminata were conducted in the field for 24 hours. Foraging activity significantly increased 4 hours before sunset and maximum foraging occurred at midnight until early morning. Three types of proteinacous food; anchovy, meat and egg yolk were tested among the five colonies of S. geminata in the field. The egg yolk was the most preferred food (100%) followed by meat (31%) and anchovy (15%). PMID:17322814

Norasmah, B; Abu Hassan, A; Che Salmah, M R; Nurita, A T; Nur Aida, H

2006-12-01

418

ASAS Centennial Paper: utilization of pasture and forages by ruminants: a historical perspective.  

PubMed

Pastures, forages, and grasslands dominate the landscape across the United States and support a large ruminant population that supplies the nation with value-added animal products. A historical perspective is presented of the innovations as they occurred in the Journal of Animal Science over the past 100 yr in pasture and forage research. Consideration was given to both animal and pasture perspectives. Areas given consideration from the animal perspective were schemes for feedstuff analysis, experimental design and statistics, forage sample preservation, indirect methods of measuring intake and digestion, TDN and energy, nutritive value, harvested forage, and innovations in the grazing environment. Areas given consideration from the forage perspective were a framework for forage-animal interface research, determining pasture yield, choice of stocking method, grazing management, partitioning of forage DM, near-infrared reflectance spectroscopy technology, antiquality constituents, and forage sample preservation. Finally, the importance was discussed of applying research results from the forage-animal interface to general ruminant nutrition research beyond the interface that is focused on altered diets. PMID:18676715

Burns, J C

2008-08-01

419

Forage selection by Royle's pika (Ochotona roylei) in the western Himalaya, India.  

PubMed

Forage selection decisions of herbivores are often complex and dynamic; they are modulated by multiple cues, such as quality, accessibility and abundance of forage plants. To advance the understanding of plant-herbivore interactions, we explored foraging behavior of the alpine lagomorph Royle's pika (Ochotona roylei) in Kedarnath Wildlife Sanctuary, India. Pika bite counts on food plants were recorded through focal sampling in three permanently marked plots. Food plant abundance was recorded by traditional quadrat procedures; forage selection was estimated with Jacob's selection index. Multiple food-choice experiments were conducted to determine whether forage selection criteria would change with variation in food plant composition. We also analyzed leaf morphology and nutrient content in both major food plants and abundantly available non-food plants. Linear regression models were used to test competing hypotheses in order to identify factors governing forage selection. Royle's pika fed primarily on 17 plant species and each forage selection decision was positively modulated by leaf area and negatively modulated by contents of avoided substances (neutral detergent fiber, acid detergent fiber, acid detergent lignin and tannin) in food plants. Furthermore, significance of the interaction term "leaf size×avoided substance" indicates that plants with large leaves were selected only when they had low avoided substance content. The forage selection criteria did not differ between field and laboratory experiments. The parameter estimates of best fit models indicate that the influence of leaf size or amount of avoided substance on pika forage selection was modulated by the magnitude of predation risk. PMID:23932023

Bhattacharyya, Sabuj; Adhikari, Bhupendra S; Rawat, Gopal S

2013-07-18

420

The Social Cognition of Social Foraging: Partner Selection by Underlying Valuation  

PubMed Central

Humans and other animals have a variety of psychological abilities tailored to the demands of asocial foraging, that is, foraging without coordination or competition with other conspecifics. Human foraging, however, also includes a unique element, the creation of resource pooling systems. In this type of social foraging, individuals contribute when they have excess resources and receive provisioning when in need. Is this behavior produced by the same psychology as asocial foraging? If so, foraging partners should be judged by the same criteria used to judge asocial patches of resources: the net energetic benefits they provide. The logic of resource pooling speaks against this. Maintaining such a system requires the ability to judge others not on their short-term returns, but on the psychological variables that guide their behavior over the long-term. We test this idea in a series of five studies using an implicit measure of categorization. Results showed that (1) others are judged by the costs they incur (a variable not relevant to asocial foraging) whereas (2) others are not judged by the benefits they provide when benefits provided are unrevealing of underlying psychological variables (despite this variable being relevant to asocial foraging). These results are suggestive of a complex psychology designed for both social and asocial foraging.

DELTON, ANDREW W.; ROBERTSON, THERESA E.

2012-01-01

421

Why do honey-bee ( Apis millifera ) foragers transfer nectar to several receivers? Information improvement through multiple sampling in a biological system  

Microsoft Academic Search

The task of nectar foraging in honey-bees is partitioned between foragers and receivers. Foragers typically transfer a nectar load in the nest as sub-loads to several receivers rather than as a single transfer. Foragers experience delays in finding receivers and use these delays to balance the number of foragers and receivers. A short delay results in the forager-recruiting waggle dance

Adam G. Hart; Francis L. W. Ratnieks

2001-01-01

422

Differential regulation of the foraging gene associated with task behaviors in harvester ants  

PubMed Central

Background The division of labor in social insect colonies involves transitions by workers from one task to another and is critical to the organization and ecological success of colonies. The differential regulation of genetic pathways is likely to be a key mechanism involved in plasticity of social insect task behavior. One of the few pathways implicated in social organization involves the cGMP-activated protein kinase gene, foraging, a gene associated with foraging behavior in social insect species. The association of the foraging gene with behavior is conserved across diverse species, but the observed expression patterns and proposed functions of this gene vary across taxa. We compared the protein sequence of foraging across social insects and explored whether the differential regulation of this gene is associated with task behaviors in the harvester ant, Pogonomyrmex occidentalis. Results Phylogenetic analysis of the coding region of the foraging gene reveals considerable conservation in protein sequence across insects, particularly among hymenopteran species. The absence of amino acid variation in key active and binding sites suggests that differences in behaviors associated with this gene among species may be the result of changes in gene expression rather than gene divergence. Using real time qPCR analyses with a harvester ant ortholog to foraging (Pofor), we found that the brains of harvester ant foragers have a daily fluctuation in expression of foraging with mRNA levels peaking at midday. In contrast, young workers inside the nest have low levels of Pofor mRNA with no evidence of daily fluctuations in expression. As a result, the association of foraging expression with task behavior within a species changes depending on the time of day the individuals are sampled. Conclusions The amino acid protein sequence of foraging is highly conserved across social insects. Differences in foraging behaviors associated with this gene among social insect species are likely due to differences in gene regulation rather than evolutionary changes in the encoded protein. The task-specific expression patterns of foraging are consistent with the task-specific circadian rhythms observed in harvester ants. Whether the molecular clock plays a role in regulating foraging gene expression (or vice versa) remains to be determined. Our results represent the first time series analysis of foraging gene expression and underscore the importance of assaying time-related expression differences in behavioral studies. Understanding how this gene is regulated within species is critical to explaining the mechanism by which foraging influences behavior.

2011-01-01

423

Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification  

PubMed Central

Background In the permanent daylight conditions north of the Arctic circle, there is a unique opportunity for bumblebee foragers to maximise intake, and therefore colony growth, by remaining active during the entire available 24-h period. We tested the foraging rhythms of bumblebee (Bombus terrestris and B. pascuorum) colonies in northern Finland during the summer, when the sun stays above the horizon for weeks. We used fully automatic radio-frequency identification to monitor the foraging activity of more than 1,000 workers and analysed their circadian foraging rhythms. Results Foragers did not use the available 24-h foraging period but exhibited robust diurnal rhythms instead. A mean of 95.2% of the tested B. terrestris workers showed robust diurnal rhythms with a mean period of 23.8 h. Foraging activity took place mainly between 08:00 and 23:00, with only low or almost no activity during the rest of the day. Activity levels increased steadily during the morning, reached a maximum around midday and decreased again during late afternoon and early evening. Foraging patterns of native B. pascuorum followed the same temporal organisation, with the foraging activity being restricted to the period between 06:00 and 22:00. Conclusions The results of the present study indicate that the circadian clock of the foragers must have been entrained by some external cue, the most prominent being daily cycles in light intensity and temperature. Daily fluctuations in the spectral composition of light, especially in the UV range, could also be responsible for synchronising the circadian clock of the foragers under continuous daylight conditions.

2010-01-01

424

Ants can learn to forage on one-way trails.  

PubMed

The trails formed by many ant species between nest and food source are two-way roads on which outgoing and returning workers meet and touch each other all along. The way to get back home, after grasping a food load, is to take the same route on which they have arrived from the nest. In many species such trails are chemically marked by pheromones providing orientation cues for the ants to find their way. Other species rely on their vision and use landmarks as cues. We have developed a method to stop foraging ants from shuttling on two-way trails. The only way to forage is to take two separate roads, as they cannot go back on their steps after arriving at the food or at the nest. The condition qualifies as a problem because all their orientation cues -- chemical, visual or any other -- are disrupted, as all of them cannot but lead the ants back to the route on which they arrived. We have found that workers of the leaf-cutting ant Atta sexdens rubropilosa can solve the problem. They could not only find the alternative way, but also used the unidirectional traffic system to forage effectively. We suggest that their ability is an evolutionary consequence of the need to deal with environmental irregularities that cannot be negotiated by means of excessively stereotyped behavior, and that it is but an example of a widespread phenomenon. We also suggest that our method can be adapted to other species, invertebrate and vertebrate, in the study of orientation, memory, perception, learning and communication. PMID:19337369

Ribeiro, Pedro Leite; Helene, André Frazão; Xavier, Gilberto; Navas, Carlos; Ribeiro, Fernando Leite

2009-04-01

425

Resource heterogeneity and foraging behaviour of cattle across spatial scales  

PubMed Central

Background Understanding the mechanisms that influence grazing selectivity in patchy environments is vital to promote sustainable production and conservation of cultivated and natural grasslands. To better understand how patch size and spatial dynamics influence selectivity in cattle, we examined grazing selectivity under 9 different treatments by offering alfalfa and fescue in patches of 3 sizes spaced with 1, 4, and 8 m between patches along an alley. We hypothesized that (1) selectivity is driven by preference for the forage species that maximizes forage intake over feeding scales ranging from single bites to patches along grazing paths, (2) that increasing patch size enhances selectivity for the preferred species, and that (3) increasing distances between patches restricts selectivity because of the aggregation of scale-specific behaviours across foraging scales. Results Cows preferred and selected alfalfa, the species that yielded greater short-term intake rates (P < 0.0001) and greater daily intake potential. Selectivity was not affected by patch arrangement, but it was scale dependent. Selectivity tended to emerge at the scale of feeding stations and became strongly significant at the bite scale, because of differences in bite mass between plant species. Greater distance between patches resulted in longer patch residence time and faster speed of travel but lower overall intake rate, consistent with maximization of intake rate. Larger patches resulted in greater residence time and higher intake rate. Conclusion We conclude that patch size and spacing affect components of intake rate and, to a lesser extent, the selectivity of livestock at lower hierarchies of the grazing process, particularly by enticing livestock to make more even use of the available species as patches are spaced further apart. Thus, modifications in the spatial pattern of plant patches along with reductions in the temporal and spatial allocation of grazing may offer opportunities to improve uniformity of grazing by livestock and help sustain biodiversity and stability of plant communities.

Utsumi, Santiago A; Cangiano, Carlos A; Galli, Julio R; McEachern, Mary B; Demment, Montague W; Laca, Emilio A

2009-01-01

426

Behavioral genomics of honeybee foraging and nest defense  

NASA Astrophysics Data System (ADS)

The honeybee has been the most important insect species for study of social behavior. The recently released draft genomic sequence for the bee will accelerate honeybee behavioral genetics. Although we lack sufficient tools to manipulate this genome easily, quantitative trait loci (QTLs) that influence natural variation in behavior have been identified and tested for their effects on correlated behavioral traits. We review what is known about the genetics and physiology of two behavioral traits in honeybees, foraging specialization (pollen versus nectar), and defensive behavior, and present evidence that map-based cloning of genes is more feasible in the bee than in other metazoans. We also present bioinformatic analyses of candidate genes within QTL confidence intervals (CIs). The high recombination rate of the bee made it possible to narrow the search to regions containing only 17-61 predicted peptides for each QTL, although CIs covered large genetic distances. Knowledge of correlated behavioral traits, comparative bioinformatics, and expression assays facilitated evaluation of candidate genes. An overrepresentation of genes involved in ovarian development and insulin-like signaling components within pollen foraging QTL regions suggests that an ancestral reproductive gene network was co-opted during the evolution of foraging specialization. The major QTL influencing defensive/aggressive behavior contains orthologs of genes involved in central nervous system activity and neurogenesis. Candidates at the other two defensive-behavior QTLs include modulators of sensory signaling ( Am5HT 7 serotonin receptor, AmArr4 arrestin, and GABA-B-R1 receptor). These studies are the first step in linking natural variation in honeybee social behavior to the identification of underlying genes.

Hunt, Greg J.; Amdam, Gro V.; Schlipalius, David; Emore, Christine; Sardesai, Nagesh; Williams, Christie E.; Rueppell, Olav; Guzmán-Novoa, Ernesto; Arechavaleta-Velasco, Miguel; Chandra, Sathees; Fondrk, M. Kim; Beye, Martin; Page, Robert E.

2007-04-01

427

Harvest management of switchgrass for biomass feedstock and forage production  

SciTech Connect

Switchgrass (Panicum virgatum L.), a warm-season perennial grass native to North America, has potential as a biomass energy crop. Their objective was to develop harvest management recommendations for biomass feedstock and forage production. Alamo switchgrass was established in 1992 at Stephenville and Dallas, TX. Four harvest frequencies (one to four cuts per year) and three final autumn harvests (Sept., Oct., or Nov.) were imposed from 1993 to 1996. Tiller densities were counted each spring. Neutral detergent fiber (NDF) and crude protein (CP) concentrations were measured in 1993 and 1994. Concentrations of NDF were lowest and of CP were highest in May-harvested biomass. Forage quality of regrowth decreased with age, reaching NDF concentrations of 790 g kg{sup {minus}1} and CP of < 20 g kg{sup {minus}1}. Total seasonal yields decreased as harvest frequency increased; however, a severe drought reversed this trend at Dallas in 1996. The highest yields occurred with a single harvest in mid-September. Delaying the final harvest until November reduced yields. Harvest date and frequency did not affect tiller density, although tiller density decreased from 900 to 650 and 630 to 310 m{sup {minus}2} at Dallas and Stephenville, respectively, during 1994 to 1997. Thus, a single mid-September harvest should maximize biomass yields in the south-central USA. A two-cut (spring-autumn) system may allow a farmer to use initial growth as forage and the regrowth for biomass, but total yields would be reduced. More frequent harvests would reduce yields further.

Sanderson, M.A.; Read, J.C.; Reed, R.L.

1999-02-01

428

Spatial context influences patch residence time in foraging hierarchies.  

PubMed

Understanding responses of organisms to spatial heterogeneity in resources has emerged as a fundamentally important challenge in contemporary ecology. We examined responses of foraging herbivores to multi-scale heterogeneity in plants. We asked the question, "Is the behavior observed at coarse scales in a patch hierarchy the collective outcome of fine scale behaviors or, alternatively, does the spatial context at coarse scales entrain fine scale behavior?" To address this question we created a nested, two-level patch hierarchy. We examined the effects of the spatial context surrounding a patch on the amount of time herbivores resided in the patch. We developed a set of competing models predicting residence time as a function of the mass of plants contained in a patch and the distance between patches and examined the strength of evidence in our observations for these models. Models that included patch mass and inter-patch distance as independent variables successfully predicted observed residence times (bears: r (2)=0.67-0.76 and mule deer: r (2)=0.33-0.55). Residence times of grizzly bears (Ursus arctos) and mule deer (Odocoileus hemionus) responded to the spatial context surrounding a patch. Evidence ratios of Akaike weights demonstrated that models containing effects of higher levels in the hierarchy on residence time at lower levels received up to 34 times more support in the data than models that failed to consider the higher level context for grizzly bears and up to 48 times more support for mule deer. We conclude that foraging by large herbivores is influenced by more than one level of heterogeneity in patch hierarchies and that simple empirical models offer a viable alternative to optimal foraging models for the prediction of patch residence times. PMID:16705439

Searle, Kate R; Vandervelde, Thea; Hobbs, N Thompson; Shipley, Lisa A; Wunder, Bruce A

2006-05-17

429

Synergy in Spreading Processes: From Exploitative to Explorative Foraging Strategies  

NASA Astrophysics Data System (ADS)

An epidemiological model which incorporates synergistic effects that allow the infectivity and/or susceptibility of hosts to be dependent on the number of infected neighbors is proposed. Constructive synergy induces an exploitative behavior which results in a rapid invasion that infects a large number of hosts. Interfering synergy leads to a slower and sparser explorative foraging strategy that traverses larger distances by infecting fewer hosts. The model can be mapped to a dynamical bond percolation with spatial correlations that affect the mechanism of spread but do not influence the critical behavior of epidemics.

Pérez-Reche, Francisco J.; Ludlam, Jonathan J.; Taraskin, Sergei N.; Gilligan, Christopher A.

2011-05-01

430

Evolutionary and anthropological perspectives on optimal foraging in obesogenic environments.  

PubMed

The nutrition transition has created an obesogenic environment resulting in a growing obesity pandemic. An optimal foraging approach provides cost/benefit models of cognitive, behavioral and physiological strategies that illuminate the causes of caloric surfeit and consequent obesity in current environments of abundant food cues; easy-access and reliable food patches; low processing costs and enormous variety of energy-dense foods. Experimental and naturalistic observations demonstrate that obesogenic environments capitalize on human proclivities by displaying colorful advertising, supersizing meals, providing abundant variety, increasing convenience, and utilizing distractions that impede monitoring of food portions during consumption. The globalization of fast foods propels these trends. PMID:16806580

Lieberman, Leslie Sue

2006-06-27

431

Temporal partitioning and aggression among foragers: modeling the effects of stochasticity and individual state  

Microsoft Academic Search

In many natural systems, individuals compete with conspecifics and heterospecifics for food and in some cases, individuals have been observed to partition their foraging times or fight over food. In this study, I investigated when it is optimal for a consumer to partition time and be aggressive. I formulated an individual-based model of foraging and used game theory to find

Shane A. Richards

2002-01-01

432

Prey depletion by the foraging of the Eurasian treecreeper, Certhia familiaris , on tree-trunk arthropods  

Microsoft Academic Search

We examined to what extent breeding insectivorous treecreepers, Certhia familiaris, affect the abundance and the mean size of their prey population on the surface of tree trunks. In order to determine foraging pressure on tree trunks, we observed the parent birds' foraging behaviour in marked squares (25Ꭱ m) at a short (10 m) and long distance (90 m) from the

Ari Jäntti; Teija Aho; Harri Hakkarainen; Markku Kuitunen; Jukka Suhonen

2001-01-01

433

Winter Active Bumblebees (Bombus terrestris) Achieve High Foraging Rates in Urban Britain  

PubMed Central

Background Foraging bumblebees are normally associated with spring and summer in northern Europe. However, there have been sightings of the bumblebee Bombus terrestris during the warmer winters in recent years in southern England. But what floral resources are they relying upon during winter and how much winter forage can they collect? Methodology/Principal Findings To test if urban areas in the UK provide a rich foraging niche for bees we set up colonies of B. terrestris in the field during two late winter periods (2005/6 & 2006/7) in London, UK, and measured their foraging performance. Fully automatic radio-frequency identification (RFID) technology was used in 2006/7 to enable us to record the complete foraging activity of individually tagged bees. The number of bumblebees present during winter (October 2007 to March 2008) and the main plants they visited were also recorded during transect walks. Queens and workers were observed throughout the winter, suggesting a second generation of bee colonies active during the winter months. Mass flowering shrubs such as Mahonia spp. were identified as important food resources. The foraging experiments showed that bees active during the winter can attain nectar and pollen foraging rates that match, and even surpass, those recorded during summer. Conclusions/Significance B. terrestris in the UK are now able to utilise a rich winter foraging resource in urban parks and gardens that might at present still be under-exploited, opening up the possibility of further changes in pollinator phenology.

Stelzer, Ralph J.; Chittka, Lars; Carlton, Marc; Ings, Thomas C.

2010-01-01

434

WHY CAN'T WE GROW FORAGE IN JULY AND AUGUST?  

Technology Transfer Automated Retrieval System (TEKTRAN)

The reason we seldom grow forage in July and August is because we seldom receive a significant amount of rain during this time. But if it were to rain a substantial amount in July and August, what and how much forage could we grow? To answer this question, we irrigated some study plots in both Jul...

435

Species-specific foraging behavior of birds in a riparian forest  

Microsoft Academic Search

In riparian forest, insectivorous birds are largely dependent on aquatic preys. However, the contribution made by aquatic preys to bird diets varies considerably among bird species. In the present study, bird foraging behaviors were observed in order to examine the relationship between bird foraging method and the variation in the contribution of aquatic preys. The great tit, the black-faced bunting,

Masashi Murakami; Shigeru Nakano

2001-01-01

436

Stand density index as a predictor of forage production in northern Arizona pine forests  

Microsoft Academic Search

Ponderosa pine (Pinus pondkrosu Laws.) overstory-forage understory relationships were studied on the Kaibab Plateau of northern Arizona to evaluate bow well forage (graminoid, forb, and current year shrub) production could be predicted by stand density index (SDI). Linear and nonlinear equations were used. Stand density index, a relative measure of stand density, was a useful predictor of understory production for

MARGARET M. MOORE; DALE A. DEITER

437

Social learning of foraging sites and escape routes in wild Trinidadian guppies  

Microsoft Academic Search

We describe two field experiments with wild guppies, Poecilia reticulata, in Trinidad that demonstrated that guppies can acquire foraging and predator escape-response information from conspecifics. In the foraging experiment, subjects were presented with two distinctly marked feeders in their home rivers. One feeder contained a conspecific shoal in a transparent container. Guppies preferred to enter the feeder containing this artificial

Simon M. Reader; Jeremy R. Kendal; Kevin N. Laland

2003-01-01

438

New modes of use and opportunities for research in forage plants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Forages play an important role in the production of meat and dairy throughout the world. Forages are not only an integral part of human protein production, but they can also improve row crop production management systems, play a role in reducing the dependence on fossil fuels and mitigate environme...

439

Estimating Forage Mass with a Commercial Capacitance Meter, Rising Plate Meter, and Pasture Ruler  

Microsoft Academic Search

tronic capacitance meter, rising plate meter, and simple pasture ruler. Accurate assessment of forage mass in pastures is key to budgeting The electronic capacitance meter relies on differences forage in grazing systems. Our objective was to determine the accuracy of an electronic capacitance meter, a rising plate meter, and a pasture in dielectric constants between air and herbage. The me-

Matt A. Sanderson; C. Alan Rotz; Stanley W. Fultz; Edward B. Rayburn

2001-01-01

440

Resource diversity and landscape-level homogeneity drive native bee foraging.  

PubMed

Given widespread declines in pollinator communities and increasing global reliance on pollinator-dependent crops, there is an acute need to develop a mechanistic understanding of native pollinator population and foraging biology. Using a population genetics approach, we determine the impact of habitat and floral resource distributions on nesting and foraging patterns of a critical native pollinator, Bombus vosnesenskii. Our findings demonstrate that native bee foraging is far more plastic and extensive than previously believed and does not follow a simple optimal foraging strategy. Rather, bumble bees forage further in pursuit of species-rich floral patches and in landscapes where patch-to-patch variation in floral resources is less, regardless of habitat composition. Thus, our results reveal extreme foraging plasticity and demonstrate that floral diversity, not density, drives bee foraging distance. Furthermore, we find a negative impact of paved habitat and a positive impact of natural woodland on bumble bee nesting densities. Overall, this study reveals that natural and human-altered landscapes can be managed for increased native bee nesting and extended foraging, dually enhancing biodiversity and the spatial extent of pollination services. PMID:23267118

Jha, Shalene; Kremen, Claire

2012-12-24

441

Self-organization of foraging behaviour: From simplicity to complexity without goals  

Microsoft Academic Search

A herbivore faces challenges while foraging-angoing changes in its physiological condition along with variation in the nutrient and toxin concentrations of foods, spatially and temporally-that make selecting a nutritious diet a vital affair. Foraging behaviours arise from simple rules that operate across levels of resolution from cells and organs to individuals and their interactions with social and physical environments. At

Frederick D. Provenza; Juan J. Villalba; Carl D. Cheney; Scott J. Werner

1998-01-01

442

Colony-based foraging segregation by Antarctic fur seals at the Kerguelen Archipelago  

Microsoft Academic Search

The foraging behaviour of conspecific female Antarctic fur seals (AFS) was compared simultaneously at 2 breeding colonies at Îles Kerguelen (S Indian Ocean). A remnant colony at ÎIes Nuageuses (IN) thought to have escaped sealing is hypothesized to be the source of increasing fur seal numbers at Cap Noir (CN) on the Kerguelen mainland. Inter-annual variability in foraging areas is

Mary-Anne Lea; Christophe Guinet; Yves Cherel; Mark Hindell; Laurent Dubroca; Sam Thalmann

2008-01-01

443

Prey to predator size ratio influences foraging efficiency of larval Aeshna juncea dragonflies  

Microsoft Academic Search

We investigated foraging behaviour of larval dragonflies Aeshna juncea in order to examine the significance of prey density and body size in predator-prey dynamics. A. juncea were offered separately three size-classes of Daphnia magna at low and high densities. The data were collected with direct observations of the foraging individuals. We found that large A. juncea larvae could better enhance

Heikki Hirvonen; Esa Ranta

1996-01-01

444

Potential of Forages to Diversify Cropping Systems in the Northern Great Plains  

Microsoft Academic Search

cated to cultivated forage crop production in the three Canadian prairie provinces (Manitoba, Saskatchewan, Cultivated forage crops are grown on almost 12 million ha on the and Alberta) and three U.S. states (North Dakota, northern Great Plains. This paper reviews the benefits of diversifying

Martin H. Entz; Vern S. Baron; Patrick M. Carr; Dwain W. Meyer; S. Ray Smith; W. Paul McCaughey

2002-01-01

445

How Information-Mapping Patterns Determine Foraging Behaviour of a Honey Bee Colony  

Microsoft Academic Search

We have developed a model of foraging behaviour of a honeybee colony based on reaction-diffusion equations and have studied how mapping the information about the explored environment to the hive determines this behaviour. The model utilizes two dominant components of colony's foraging behaviour — the recruitment to the located nectar sources and the abandonment of them. The recruitment is based

Valery Tereshko; Troy Lee

2002-01-01

446

Octopamine modulates responsiveness to foraging-related stimuli in honey bees ( Apis mellifera )  

Microsoft Academic Search

The biogenic amine neurochemical octopamine is involved in the onset of foraging behaviour in honey bees. We tested the hypothesis that octopamine influences honey bee behavioural development by modulating responsiveness to task-related stimuli. We examined the effect of octopamine treatment on responsiveness to brood pheromone (an activator of foraging) and to the presence of older bees in the colony (an

A. B. Barron; D. J. Schulz; G. Robinson

2002-01-01

447

Effects of plant density on forage production in five populations of kleingrass  

Microsoft Academic Search

Kleingrass (Panicum coloratum L.) forage yield evaluation plots are often established at a density of 6.0 plants m to accommodate mechanical transplanting and harvesting equipment. However, forage crops are usually established from seed at higher plant densities. Experiments were conducted to determine if populations respond dissimilarly to planting density, and if the ability to statistically distinguish among populations is density?dependent.

B. A. Young; C. R. Tischler

1995-01-01

448

Potential food production from forage legume-based-systems in Europe: an overview  

Microsoft Academic Search

Intensification of EU livestock farming systems has been accompanied by the devel- opment of maize silage and intensively fertilised grasses at the expense of forage legume crops. However in the new context of agriculture, the development of forage legumes constitutes one of the pillars for future livestock farming systems with high environmental and economical performances. Yield benefits of grass-clover mixtures

J. L. Peyraud; A. Le Gall; A. Lüscher

2009-01-01

449

Selective foraging on woody plant species by the Eurasian beaver ( Castorber ) in Telemark, Norway  

Microsoft Academic Search

Beavers Castor spp. are generalist herbivores, feeding on the bark, shoots and leaves of woody plants, terrestrial herbs and forbs, ferns and aquatic vegetation. As central-place foragers, beavers move out from water to select and cut trees and vegetation, and then transport it back to their refuge. These terrestrial forays are energetically costly; therefore, beavers should concentrate their foraging activity

O. Haarberg; F. Rosell

450

Relationships of Forage Compositions With Rates of Cell Wall Digestion and Indigestibility of Cell Walls  

Microsoft Academic Search

Forage fiber digestion followed first- order reaction kinetics even though in- dividual forages differed widely in ma- turity, composition, and rate of fiber digestion. Linearity of individual semilog plots of remaining digestible cell walls on time and their individually high r z (mean ,978) for each of 112 different samples representing 15 species support this general model. Cell wall digestion

L. W. Smith; H. K. Goering; C. H. Gordon

1972-01-01

451

Designing supplementation programs for beef cattle fed forage-based diets1,2  

Microsoft Academic Search

Reasons for feeding supplements to cattle consuming forage-based diets include conservation of forage, improvement of animal performance, increasing economic return, and(or) managing cattle behavior. This review focuses on identifying the limit- ing nutrients, effects of source of carbohydrates in energy supplements, feed additives, and feeding systems. The first step in designing a supplement is to determine nutrients that limit utilization

W. E. Kunkle; J. T. Johns; M. H. Poore

452

Alternative temperate forages containing secondary compounds for improving sustainable productivity in grazing ruminants  

Microsoft Academic Search

The use of alternative temperate forages to improve the sustainable productivity of grazing ruminants, relative to grass-based pastures, is reviewed. Particular emphasis is placed upon forages containing secondary compounds for sustainable control of internal parasites, for increasing reproductive rate in sheep, reducing bloat risk in cattle and for reducing methane production as a means of lowering greenhouse gas emissions.Of the

C. A. Ramírez-Restrepo; T. N. Barry

2005-01-01

453

The effects of human presence, flock size and prey density on shorebird foraging rates  

Microsoft Academic Search

Animals may alter their foraging behaviour in the presence of humans because they perceive humans as potential predators. In this study I determined whether people caused shorebirds to reduce feeding rates at a stopover site in coastal British Columbia, Canada. I controlled for prey density and flock size because these variables may influence both the foraging rates as well as

Maï Yasué

2005-01-01

454

Migration routes and foraging behaviour of olive ridley turtlesLepidochelys olivaceain northern Australia  

Microsoft Academic Search

The foraging ecology of endangered olive ridley Lepidochelys olivacea sea turtles is poorly known in Australia, with only a limited knowledge of their foraging distribution inferred from captures in trawl net fisheries. We attached satellite transmitters to 8 olive ridley turtles in 2004 and 2005 at a nesting beach in Australia's Northern Territory to document their migratory routes and for-

S. D. Whiting; J. L. Long; M. Coyne

2007-01-01

455

Geographic profiling applied to testing models of bumble-bee foraging  

PubMed Central

Geographic profiling (GP) was originally developed as a statistical tool to help police forces prioritize lists of suspects in investigations of serial crimes. GP uses the location of related crime sites to make inferences about where the offender is most likely to live, and has been extremely successful in criminology. Here, we show how GP is applicable to experimental studies of animal foraging, using the bumble-bee Bombus terrestris. GP techniques enable us to simplify complex patterns of spatial data down to a small number of parameters (2–3) for rigorous hypothesis testing. Combining computer model simulations and experimental observation of foraging bumble-bees, we demonstrate that GP can be used to discriminate between foraging patterns resulting from (i) different hypothetical foraging algorithms and (ii) different food item (flower) densities. We also demonstrate that combining experimental and simulated data can be used to elucidate animal foraging strategies: specifically that the foraging patterns of real bumble-bees can be reliably discriminated from three out of nine hypothetical foraging algorithms. We suggest that experimental systems, like foraging bees, could be used to test and refine GP model predictions, and that GP offers a useful technique to analyse spatial animal behaviour data in both the laboratory and field.

Raine, Nigel E.; Rossmo, D. Kim; Le Comber, Steven C.

2008-01-01

456

Geographic profiling applied to testing models of bumble-bee foraging.  

PubMed

Geographic profiling (GP) was originally developed as a statistical tool to help police forces prioritize lists of suspects in investigations of serial crimes. GP uses the location of related crime sites to make inferences about where the offender is most likely to live, and has been extremely successful in criminology. Here, we show how GP is applicable to experimental studies of animal foraging, using the bumble-bee Bombus terrestris. GP techniques enable us to simplify complex patterns of spatial data down to a small number of parameters (2-3) for rigorous hypothesis testing. Combining computer model simulations and experimental observation of foraging bumble-bees, we demonstrate that GP can be used to discriminate between foraging patterns resulting from (i) different hypothetical foraging algorithms and (ii) different food item (flower) densities. We also demonstrate that combining experimental and simulated data can be used to elucidate animal foraging strategies: specifically that the foraging patterns of real bumble-bees can be reliably discriminated from three out of nine hypothetical foraging algorithms. We suggest that experimental systems, like foraging bees, could be used to test and refine GP model predictions, and that GP offers a useful technique to analyse spatial animal behaviour data in both the laboratory and field. PMID:18664426

Raine, Nigel E; Rossmo, D Kim; Le Comber, Steven C

2009-03-01

457

Online Shopping as Foraging: The Effects of Increasing Delays on Purchasing and Patch Residence  

Microsoft Academic Search

This paper extends the Behavioral Ecology of Consumption, a foraging theory model of human decision-making in an online environment, in a replication and extension of previous online foraging research. Participants shopped for music CDs in a simulated internet mall featuring five virtual music stores with delay to in-stock feedback of 2, 4, 8, 16, and 32 seconds. Preference was measured

Donald A. Hantula; Diane DiClemente Brockman; Carter L. Smith

2008-01-01

458

Integration of Forages for Cattle and Goats into Plantation Systems in Thailand  

Microsoft Academic Search

The integration of forages for livestock has considerable prospects in Thailand. Forage species must be shade-tolerant and must not be too competitive. The prospects for integration appear to be best for the higher light transmission and lower value plantation crops such as coconuts and fruit trees, where additional income from livestock would be of major benefit to the farmer. In

P. Sophanodora; S. Tudsri

459

Characteristics of Plant Cell Walls Affecting Intake and Digestibility of Forages by Ruminants  

Microsoft Academic Search

Even under the intensive concentrate feeding systems of ruminant animal production in the United States, forages continue to represent the single most important feed resource. Cell-wall concentration and digestibility limit the intake potential and energy availability of forage crops in beef and dairy produc- tion. Identification of cell-wall characteristics that should be targets of genetic modification is required if plant

H. G. Jung; M. S. Allen

1995-01-01

460

Regeneration of genetically diverse plants from tissue cultures of forage grass — Panicum sps  

Microsoft Academic Search

Callus tissue cultures of 3 species of forage-grass (Panicum) were established from the excised embryos, shoot tips, and segments of young inflorescences, and induced to regenerate plants showing genetic diversity. These plants were transferred to the soil, and reared to maturity. The importance of in vitro methods for increasing the reservoirs of germplasm in forage-improvement programs is emphasized.

Y. P. S. Bajaj; B. S. Sidhu; V. K. Dubey

1981-01-01

461

Response of eleven forage species to treatment of acid soil with calcitic and dolomitic lime  

Microsoft Academic Search

The cost and difficulty of applying lime on hilly pastures or small forage fields makes it appropriate to devote attention to efficiency of lime utilization. This study evaluated effects of calcitic and dolomitic lime on yield and mineral composition of 11 forage species grown on soil with a low base status of 0.46 cmolc as Ca and 0.18 cmolc as

A. L. Pires; J. L. Ahirichs; C. L. Rhykerd

1992-01-01

462

Information flow and regulation of foraging activityin bumble bees ( Bombus spp.)  

Microsoft Academic Search

Communication in the context of foraging in bumble bees has received less attention than in other social bees. Yet, recent studies have revealed that information flow mediates colony foraging activity. The species studied do not recruit to specific locations, but bees can learn the scent of food sources at the nest, which may reduce their search time. Location communication may

Anna DORNHAUSa; Lars Chittka

2004-01-01

463

Estimation of bermudagrass forage intake from canopy spectral absorbance measurements using hyperspectral radiometry  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hyperspectral forage canopy absorbance was estimated on eight random plots in each of three 1.2 ha common bermudagrass pastures weekly over a period of 9 weeks from June through early August, 2005 using spectroradiometers measuring light reflectance from 410 nm to 1010 nm. Forage in each plot was ...

464

Prospects for Improving Forage Supply in Coconut Plantations of the South Pacific  

Microsoft Academic Search

This paper analyses the reasons for success or failure of forages and cattle under coconuts and discusses the future potential for improvement of forages under coconuts within the physical and socio-economic environment of the South Pacific. The South Pacific Region THE countries and people of the South Pacific have many unique characteristics which separate them from the Asian region with

H. M. Shelton

465

Sex differences in the foraging behavior of squirrel monkeys in a seasonal habitat  

Microsoft Academic Search

The effects of sex and seasonal changes in food abundance on foraging behavior was studied in squirrel monkeys (Saimiri oerstedi) in Costa Rica over an eleven-month period. Females searched for and ate food at significantly greater frequencies than did males throughout the study. The frequency of the specific foraging techniques used occasionally differed significantly within seasons, but not across the

S. Boinski

1988-01-01

466

Effects of pollen quality and genotype on the dance of foraging honey bees  

Microsoft Academic Search

Animals assess the quality and quantity of food and choose among different foods based on these assessments. We explored whether there was genetic variation for assessment of pollen quality by foraging honey bees,Apis mellifera. Honey bees derived from two genotypic strains foraged for pollen of varying quality from a petri dish placed inside an outdoor flight cage. The strains were

KEITH D. WADDINGTON; C. MINDY NELSON; ROBERT E. PAGE

1998-01-01

467

Spatial patterns in army ant foraging and migration: Eciton burchelli on Barro Colorado Island, Panama  

Microsoft Academic Search

Eciton burchelli colonies alternate bouts of central place foraging with periods of migration according to a set rhythm. When these army ants forage from a central nest site they separate neigh-bouring raids by using a pattern similar to that used by many plants in spiral phyllotaxis. During the intervening periods of migration, raids and emigrations are orientated to lower the

Nigel R. Franks; Charles R. Fletcher

1983-01-01

468

Mechanisms of dispersed central-place foraging in polydomous colonies of the Argentine ant  

Microsoft Academic Search

Many species of ants occupy multiple nests, a condition known as polydomy. Because of their decentralized structure, polydomous colonies may be removed from some of the constraints associated with classic central-place foraging. We used laboratory and field experiments to assess the mechanisms involved in dispersed central-place foraging in polydomous colonies of the Argentine ant Linepithema humile, a widespread invasive species.

David A. Holway; Ted J. Case

2000-01-01

469

The Value of Information in Central-Place Foraging. Research Report  

Microsoft Academic Search

We consider a central place forager with two qualitatively different types of food sources; type 1 sources are always available whereas type 2 sources become available intermittently and this availability is signalled by information present at the central place. Source 1 is modelled using a standard patch foraging model whereas source 2 is modelled somewhat schematically in terms of the

E. J. Collins; A. I. Houston; J. M. McNamara

470

Interference competition, payoff asymmetries, and the social relationships of central place foragers  

Microsoft Academic Search

We present a central place foraging model that shows how payoff asymmetries originate in contests for access to resources. The essence of the model is that inter- ference competition at resource points lowers the rate at which foragers can load prey, thereby depressing the rate of food delivery to the central place. We show that interference leads to asymmetric payoffs

R. C. YDENBERG; L GIRALDEAU; D KRAMER

1986-01-01

471

NEMATODE DENSITIES IN YEAR-ROUND FORAGE PRODUCTION SYSTEMS UTILIZING MANURE FERTILIZATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

This research was part of a larger study to evaluate the efficiency of year-round forage production systems for utilizing dairy manure. Two forage systems were evaluated: the CBR system was a rotation of temperate corn (Zea mays L.), coastal bermudagrass [Cynodon dactylon (L.) Pers], and a mixtur...

472

Foraging response of the ant Lasius pallitarsis to food sources with associated mortality risk  

Microsoft Academic Search

Summary Lasius pallitarsis (Provancher) ant colonies were offerred a choice between two food patches of equal nutritive quality but with one of the patches having associated with it one of several types of mortality risk indicators. Foraging decisions appeared to be affected only when theL. pallitarsis foragers could actually physically encounter a potential mortality agent (a largerFormica subnuda Emery). Odors

P. Nonacs; L. M. Dill

1988-01-01

473

EFFECT OF ROW SPACING, CULTIVAR, AND GROWTH STAGE ON SOYBEAN FORAGE YIELD AND QUALITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Effective management of soybean grown in north-central Texas requires knowledge of its potential value as a forage and grain crop. To better understand these uses, a forage soybean cultivar (Tyrone) and Deltapine DP 5110S were planted in 14-inch and 28-inch rows on 11 May 2001 and 16 May 2002 (with...

474

ESTIMATE OF FORAGE YIELD LOSS IN EASTERN GAMAGRASS DUE TO SHOOT BORING INSECTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Eastern gamagrass [Tripsacum dactyloides (L.) L.] has high forage production and high quality forage that can be used for pasture, hay, and ensilage. Two insects are known to infest the shoots of eastern gamagrass. These are the southern cornstalk borer [Diatraea crambidoides (Grote)] and the maiz...

475

Parasitic infection leads to decline in hemolymph sugar levels in honeybee foragers  

Microsoft Academic Search

Parasites by drawing nutrition from their hosts can exert an energetic stress on them. Honeybee foragers with their high metabolic demand due to flight are especially prone to such a stress when they are infected. We hypothesized that infection by the microsporidian gut parasite Nosema ceranae can lower the hemolymph sugar level of an individual forager and uncouple its energetic

Christopher Mayack; Dhruba Naug

2010-01-01

476

DIRECT VERSES SEQUENTIAL ANALYSIS OF ACID-DETERGENT INSOLUBLE NITROGEN IN FORAGE LEGUME HAYS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Acid-detergent insoluble nitrogen (ADIN) is thought to represent nitrogen that is not degraded during ruminal and post-ruminal digestion of forages by cattle. Forage ADIN can be determined following direct acid detergent extraction or following sequential extraction with neutral and acid detergents....

477

Thiamine and Thiaminase Status in Forage Fish of Salmonines from Lake Michigan  

Microsoft Academic Search

Dietary sources of thiamine (vitamin B1) and thiamine-degrading enzymes (thiaminases) are thought to be primary factors in the development of thiamine deficiency among Great Lakes salmonines. We surveyed major forage fish species in Lake Michigan for their content of thiamine, thiamine vitamers, and thiaminase activity. Concentrations of total thiamine were similar (P ? 0.05) among most forage fishes (alewife Alosa

Donald E. Tillitt; James L. Zajicek; Scott B. Brown; Lisa R. Brown; John D. Fitzsimons; Dale C. Honeyfield; Mark E. Holey; Gregory M. Wright

2005-01-01

478

Food abundance and foraging patterns of natural colonies of Polyrhachis vicina Roger (Hymenoptera: Formicidae)  

Microsoft Academic Search

Summary The foraging pattern ofPolyrhachis vicina Roger, the composition of food collected, and the abundance and distribution of food sources were studied. Results showed:1.The food collected by workers was mostly honeydew secreted by Homoptera supplemented by small insects and plant secretions. The successful foraging rate was 35% in April, 74% in June, 91 % in August, and 83 % in

J.-F. Wang; J. Tang

1994-01-01

479

R E LATIONSH IP BETWE EN F ECAL COMPON ENTS AND FORAGE CONSUMPTION AND DIGESTIBILITY 1  

Microsoft Academic Search

Summary Thirty-nine in vivo total collection digestion determinations were performed with steers with the purpose of relating a selected array of fecal components to forage intake and digestibility. These determinations were made during the spring, summer and fall of 1978 with eight steers averaging 218 kilograms. The forages were freshly cut fescue and frozen green legumes (crimson clover, three cuttings

R. E. EsteLl II; W. T. Butts

2010-01-01

480

Biomass production and quality of indian-origin forage Guar in Southern Great Plains  

Technology Transfer Automated Retrieval System (TEKTRAN)

Guar [Cyamopsis tetragonoloba (L.) Taub.] is a warm-season annual pulse grown in semi-arid regions of the world as a multi-purpose vegetable, forage, cover or fodder crop. Guar could provide late summer forage in the southern Great Plains (SGP), but has largely been used as a grain crop, and no func...

481

Corticosterone and foraging behavior in a diving seabird: The Adélie penguin, Pygoscelis adeliae  

Microsoft Academic Search

Because hormones mediate physiological or behavioral responses to intrinsic or extrinsic stimuli, they can help us understand how animals adapt their foraging decisions to energetic demands of reproduction. Thus, the hormone corticosterone deserves specific attention because of its influence on metabolism, food intake and locomotor activities. We examined the relationships between baseline corticosterone levels and foraging behavior or mass gain

Frédéric Angelier; Charles-André Bost; Mathieu Giraudeau; Guillaume Bouteloup; Stéphanie Dano; Olivier Chastel

2008-01-01

482

Genetic diversity within honeybee colonies increases signal production by waggle-dancing foragers.  

PubMed

Recent work has demonstrated considerable benefits of intracolonial genetic diversity for the productivity of honeybee colonies: single-patriline colonies have depressed foraging rates, smaller food stores and slower weight gain relative to multiple-patriline colonies. We explored whether differences in the use of foraging-related communication behaviour (waggle dances and shaking signals) underlie differences in foraging effort of genetically diverse and genetically uniform colonies. We created three pairs of colonies; each pair had one colony headed by a multiply mated queen (inseminated by 15 drones) and one colony headed by a singly mated queen. For each pair, we monitored the production of foraging-related signals over the course of 3 days. Foragers in genetically diverse colonies had substantially more information available to them about food resources than foragers in uniform colonies. On average, in genetically diverse colonies compared with genetically uniform colonies, 36% more waggle dances were identified daily, dancers performed 62% more waggle runs per dance, foragers reported food discoveries that were farther from the nest and 91% more shaking signals were exchanged among workers each morning prior to foraging. Extreme polyandry by honeybee queens enhances the production of worker-worker communication signals that facilitate the swift discovery and exploitation of food resources. PMID:18198143

Mattila, Heather R; Burke, Kelly M; Seeley, Thomas D

2008-04-01

483

Black-Capped Chickadees (Poecile atricapillus) Anticipate Future Outcomes of Foraging Choices  

Microsoft Academic Search

In 2 experiments we investigated the cognitive abilities of wild-caught black-capped chickadees (Poecile atricapillus) in future anticipation tasks. Chickadees were sensitive to anticipatory contrast effects over time horizons of 5, 10, and 30 min (Experiment 1). Chickadees also learned the order of events and anticipated that the quality of future foraging outcomes was contingent on current foraging choices. This behavior

Miranda C. Feeney; William A. Roberts; David F. Sherry

2011-01-01

484

Nutrient limitation of plant growth and forage quality in Arctic coastal marshes  

Microsoft Academic Search

Summary 1 Foraging by geese has led to vegetation loss in salt marshes along the Hudson Bay coast and lesser snow geese are increasingly grazing inland freshwater marshes. We determined whether different nutrients limit the growth of forage plants in the two hab- itats, and whether these differences affect the nutritional quality of vegetation available to geese at La Pérouse

JACQUELINE T. NGAI; ROBERT L. JEFFERIES

2004-01-01

485

Forage management impacts I: Soil phosphorus fractions and P export in runoff  

Technology Transfer Automated Retrieval System (TEKTRAN)

A greater understanding of the role of forage management impacts on soil P fractions and P export in runoff at the field-scale can enhance agricultural sustainability and water quality. Eighteen farm fields, with forages managed as pasture or hay systems were outfitted with small in-field runoff co...

486

Effect of Forage Maturity on Ration Digestibility and Production by Dairy Cows1  

Microsoft Academic Search

Mixed grass-legume silages harvested at early and late maturities from the same field were evaluated in three trials to determine maturity effects on ration digestibility when forages were fed alone or in complete rations. In situ dry matter disappearance was examined using a rumen-fistulated steer. Rate of disap- pearance of potentially digestible dry matter was reduced for forage of greater

R. M. Cleale IV; L. S. Bull

1986-01-01

487

Predation risk and foraging behavior of the hoary marmot in Alaska  

Microsoft Academic Search

I observed hoary marmots for three field seasons to determine how the distribution of food and the risk of predation influenced marmots' foraging behavior. I quantified the amount of time Marmota caligata foraged in different patches of alpine meadows and assessed the distribution and abundance of vegetation eaten by marmots in these meadows. Because marmots dig burrows and run to

Warren G. Holmes

1984-01-01

488

Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification  

Microsoft Academic Search

BACKGROUND: In the permanent daylight conditions north of the Arctic circle, there is a unique opportunity for bumblebee foragers to maximise intake, and therefore colony growth, by remaining active during the entire available 24-h period. We tested the foraging rhythms of bumblebee (Bombus terrestris and B. pascuorum) colonies in northern Finland during the summer, when the sun stays above the

Ralph J Stelzer; Lars Chittka

2010-01-01

489

Food availability affects Osmia pumila (Hymenoptera: Megachilidae) foraging, reproduction, and brood parasitism  

Microsoft Academic Search

Food limitation can reduce reproductive success directly, as well as indirectly, if foraging imposes a risk of predation or parasitism. The solitary bee Osmia pumila suffers brood parasitism by the cleptoparasitic wasp Sapyga centrata, which enters the host nest to oviposit while the female bee is away. I studied foraging and reproduction of O. pumila nesting within cages stocked with

Karen Goodell

2003-01-01

490

IDENTIFYING TRITICALE (X TRITICOSECALE WITTMACK) FORAGE LINES ADAPTED TO NEBRASKA'S GROWING CONDITIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Triticale, a human-made crop that combines the diversity of wheat and rye, is mainly used as a forage crop in Nebraska; therefore, cultivar selection should encompass high energy content of the forage and good grain yield so the seed can be economically produced. Hence, the objective of this study w...

491

Stable Isotopic Insights into the Foraging Ecology of an Endangered Marine Predator, the Hawaiian Petrel  

Microsoft Academic Search

Seabirds play vital roles in their ecosystems, both as predators in their oceanic foraging grounds and conduits of marine nutrients to island nesting sites. Despite growing evidence that food availability limits seabird populations, characterization of the diet and even foraging locations of some seabird species remains elusive. Here, we use stable carbon (delta13C) and nitrogen (delta15N) isotopes to study the

A. E. Wiley; P. H. Ostrom; H. F. James

2010-01-01

492

Characterization and Identification of Pediococcus Species Isolated from Forage Crops and Their Application for Silage Preparation  

Microsoft Academic Search

Pediococcus species isolated from forage crops were characterized, and their application to silage preparation was studied. Most isolates were distributed on forage crops at low frequency. These isolates could be divided into three (A, B, and C) groups by their sugar fermentation patterns. Strains LA 3, LA 35, and LS 5 are representative isolates from groups A, B, and C,

YIMIN CAI; SUMIO KUMAI; MASUHIRO OGAWA; YOSHIMI BENNO; TAKASHI NAKASE

1999-01-01

493

A novel technique for multilevel optimal magnetic resonance brain image thresholding using bacterial foraging  

Microsoft Academic Search

The present paper proposes a novel optimal multilevel thresholding algorithm for brain magnetic resonance image segmentation. This optimization algorithm, employed for image histogram-based thresholding, is based on a relatively recently proposed evolutionary approach, namely, bacterial foraging. Originally proposed towards the fag end of last millennium, bacterial foraging is emerging as a strong contender for distributed control and optimization. The utility

Madhubanti Maitra; Amitava Chatterjee

2008-01-01

494

Add shamans and stir? A critical review of the shamanism model of forager rock art production  

Microsoft Academic Search

The “shamanism” or “neurpsychological” model proposed by Lewis-Williams and colleagues has had a powerful impact on rock art research, and has significantly added to our knowledge of past foragers lifeways in southern Africa and elsewhere in the world. However, this model is primarily based on the view of shamanism as a universal and unvarying characteristic of foragers over space and

Grant S. McCall

2007-01-01

495

The rewards of restraint in the collective regulation of foraging by harvester ant colonies.  

PubMed

Collective behaviour, arising from local interactions, allows groups to respond to changing conditions. Long-term studies have shown that the traits of individual mammals and birds are associated with their reproductive success, but little is known about the evolutionary ecology of collective behaviour in natural populations. An ant colony operates without central control, regulating its activity through a network of local interactions. This work shows that variation among harvester ant (Pogonomyrmex barbatus) colonies in collective response to changing conditions is related to variation in colony lifetime reproductive success in the production of offspring colonies. Desiccation costs are high for harvester ants foraging in the desert. More successful colonies tend to forage less when conditions are dry, and show relatively stable foraging activity when conditions are more humid. Restraint from foraging does not compromise a colony's long-term survival; colonies that fail to forage at all on many days survive as long, over the colony's 20-30-year lifespan, as those that forage more regularly. Sensitivity to conditions in which to reduce foraging activity may be transmissible from parent to offspring colony. These results indicate that natural selection is shaping the collective behaviour that regulates foraging activity, and that the selection pressure, related to climate, may grow stronger if the current drought in their habitat persists. PMID:23676676

Gordon, Deborah M

2013-05-15

496

Benthic and pelagic dives: a new foraging behaviour in rockhopper penguins  

Microsoft Academic Search

The pattern and characteristics of diving of 55 daily foraging trips performed by 16 female southern rockhopper penguins Eudyptes chrysocome filholi were studied in coastal waters of Kerguelen Archipelago during the guard stage. Diving patterns and dive profiles indicated that birds used 2 foraging behaviours. First, they performed typical pelagic dives, as previously decribed for other penguin species. Second, they

Yann Tremblay; Yves Cherel

2000-01-01

497

Effects of Selection for Honey Bee Worker Reproduction on Foraging Traits  

Microsoft Academic Search

The “reproductive ground plan” hypothesis (RGPH) proposes that reproductive division of labour in social insects had its antecedents in the ancient gene regulatory networks that evolved to regulate the foraging and reproductive phases of their solitary ancestors. Thus, queens express traits that are characteristic of the reproductive phase of solitary insects, whereas workers express traits characteristic of the foraging phase.

Benjamin P. Oldroyd; Madeleine Beekman

2008-01-01

498

SPATIAL VARIABILITY AND RELATIONSHIPS AMONG SELECTED SOIL AND FORAGE TRAITS IN A WINTER WHEAT PASTURE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Millions of stocker calves in the southern Great Plains are grazed each year on winter wheat (Triticum aestivum L.) pastures. During the first 3 weeks of grazing wheat, stockers often gain little or no weight even though the quality of forage is considered excellent. Because forage factors may affec...

499

Identifying Winter Forage Triticale (X Triticosecale Wittmack) Strains for the Central Great Plains  

Technology Transfer Automated Retrieval System (TEKTRAN)

Triticale (X Triticosecale Wittmack), a human-made crop, is mainly used as a forage crop in the central Great Plains. A successful triticale cultivar should have high forage yield with good quality, and also high grain yield so the seed can be economically produced. Hence, the purpose of this study...

500

Influence of Brown Midrib, Leafy, and Transgenic Hybrids on Corn Forage Production  

Microsoft Academic Search

compared with silage from a normal counterpart (Oba and Allen, 1999). Hybrid selection strongly influences corn (Zea mays L.) forage Compared with normal hybrids, leafy hybrids contain production. Limited forage production and quality information exists for leafy and transgenic hybrids (Bacillus thuringiensis (Bt) and herbi- additional leaves above the ear, which should increase cide resistant). We compared dry matter (DM)

William J. Cox; Debbie J. R. Cherney

2001-01-01