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Author Conradt, L.; Roper, T.J.
Title Group decision-making in animals Type Journal Article
Year 2003 Publication Nature Abbreviated Journal Nature
Volume (down) 421 Issue 6919 Pages 155-158
Keywords Animals; Behavior, Animal/*physiology; *Decision Making; Democracy; Group Processes; *Models, Biological; Population Density; Social Behavior
Abstract Groups of animals often need to make communal decisions, for example about which activities to perform, when to perform them and which direction to travel in; however, little is known about how they do so. Here, we model the fitness consequences of two possible decision-making mechanisms: 'despotism' and 'democracy'. We show that under most conditions, the costs to subordinate group members, and to the group as a whole, are considerably higher for despotic than for democratic decisions. Even when the despot is the most experienced group member, it only pays other members to accept its decision when group size is small and the difference in information is large. Democratic decisions are more beneficial primarily because they tend to produce less extreme decisions, rather than because each individual has an influence on the decision per se. Our model suggests that democracy should be widespread and makes quantitative, testable predictions about group decision-making in non-humans.
Address School of Biological Sciences, University of Sussex, Brighton BN1 9QG, UK. l.conradt@sussex.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes PMID:12520299 Approved no
Call Number Equine Behaviour @ team @ Serial 5136
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Author de Waal, F.B.; Aureli, F.; Judge, P.G.
Title Coping with crowding Type Journal Article
Year 2000 Publication Scientific American Abbreviated Journal Sci Am
Volume (down) 282 Issue 5 Pages 76-81
Keywords *Adaptation, Psychological; Animals; Behavior, Animal; Emotions; Female; Grooming; Homicide; Humans; Macaca mulatta; Male; Pan troglodytes; *Population Density; Primates; Rodentia; Rural Population; Territoriality; Urban Population; Violence
Abstract
Address Living Links Center, Yerkes Regional Primate Research Center, Atlanta, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0036-8733 ISBN Medium
Area Expedition Conference
Notes PMID:11056991 Approved no
Call Number refbase @ user @ Serial 184
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Author Dubois, F.; Giraldeau, L.-A.
Title The forager's dilemma: food sharing and food defense as risk-sensitive foraging options Type Journal Article
Year 2003 Publication The American Naturalist Abbreviated Journal Am Nat
Volume (down) 162 Issue 6 Pages 768-779
Keywords Animals; Competitive Behavior/*physiology; *Environment; Feeding Behavior/*physiology; *Game Theory; *Models, Biological; Population Density; Population Dynamics
Abstract 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.
Address Departement des Sciences Biologiques, Universite du Quebec a Montreal, Case postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. fdubois@u-bourgogne.fr
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-0147 ISBN Medium
Area Expedition Conference
Notes PMID:14737714 Approved no
Call Number Serial 2132
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Author Li, C.; Jiang, Z.; Tang, S.; Zeng, Y.
Title Influence of enclosure size and animal density on fecal cortisol concentration and aggression in Pere David's deer stags Type Journal Article
Year 2007 Publication General and Comparative Endocrinology Abbreviated Journal Gen Comp Endocrinol
Volume (down) 151 Issue 2 Pages 202-209
Keywords *Aggression; Animals; *Deer; *Environment; Feces/*chemistry; Handling (Psychology); Housing, Animal; Hydrocortisone/*analysis; Male; Population Density
Abstract We investigated the impact of enclosure size and animal density on behavior and adrenocortical secretion in Pere David's deer in Dafeng Nature Reserve, China. From February 15 to April 16 in 2004, we conducted two experiments. First, we studied maintenance behavior and conflict behavior of Pere David's deer stags in a large enclosure (200 ha) with low animal density (0.66 deer/ha) and a small display pen (0.75 ha) with high animal density (25.33 deer/ha). The maintenance behavior we recorded included standing, locomotion, foraging and rest. During the behavioral observations, we collected fresh voided fecal samples from the stags periodically, and analyzed the fecal cortisol concentrations in those samples using radioimmunoassay technique. Second, we monitored the fecal cortisol concentrations of one group of stags (12 deer lived in an enclosure of 100 ha) before and after transferred into a small pen (0.5 ha). We found that in the first experiment: (1) there were significant differences in standing and rest whereas no significant differences of locomotion and foraging between the free-ranging group and the display group; (2) frequency of conflict behavior in the display group was significantly higher than those in the free-ranging group; and (3) fecal cortisol concentration of the display group (326.17+/-16.98 ng/g dry feces) was significantly higher than that of the free-ranging group (268.98+/-15.21 ng/g dry feces). In the second experiment, there was no significant difference of the fecal cortisol concentrations among sampling days, but the mean fecal cortisol concentration of the day after transferring (337.46+/-17.88 ng/g dry feces) was significantly higher than that of the day before transferring (248.44+/-7.99 ng/g dry feces). Comparison with published findings, our results indicated that enclosure size and animal density affect not only behaviors, but also adrenocortical secretion in Pere David's deer. Small living space with high animal density may impose physiological stress to captive Pere David's deer. Moreover, long-term physiological stress and increase of conflict behavior may subsequently affect survival and reproduction of the deer.
Address Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0016-6480 ISBN Medium
Area Expedition Conference
Notes PMID:17324429 Approved no
Call Number Equine Behaviour @ team @ Serial 5475
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Author Gauvin, S.; Giraldeau, L.-A.
Title Nutmeg mannikins ( Lonchura punctulata) reduce their feeding rates in response to simulated competition Type Journal Article
Year 2004 Publication Oecologia Abbreviated Journal Oecologia
Volume (down) 139 Issue 1 Pages 150-156
Keywords Animals; *Feeding Behavior; Population Density; *Social Behavior; *Songbirds
Abstract Group feeding animals experience a number of competitive foraging costs that may result in a lowered feeding rate. It is important to distinguish between reductions in feeding rates that are caused by reduced food availability and physical interactions among foragers from those caused by the mere presence of foraging companions that may be self-imposed in order to obtain some benefit of group membership. Starlings ( Sturnus vulgaris) reduce their feeding rates when in the company of simulated competitors located in an adjacent cage that cannot affect the food availability or interact with the forager. In the present study, we investigate whether the presence of simulated competitors in another species of passerine, nutmeg mannikins ( Lonchura punctulata), can result in self-imposed reductions in feeding rates. When feeding in the company of simulated competitors, mannikins spent more non-foraging time near them, fed more slowly, reduced travel times between patches, reduced their scanning time and pecked more slowly. These results provide evidence that simulated competitors induce a reduction in pecking rate: behavioural interference. These self-imposed responses to competitors may have resulted from attempts to remain close to the non-feeding companions. Such self-imposed reductions in feeding rates may be a widespread yet generally unrecognised foraging cost to group feeding individuals.
Address Department of Biology, Concordia University, Montreal, Quebec, Canada
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0029-8549 ISBN Medium
Area Expedition Conference
Notes PMID:14722748 Approved no
Call Number Serial 2133
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Author Cancedda, M.
Title [Social and behavioral organization of horses on the Giara (Sardinia): distribution and aggregation] Type Journal Article
Year 1990 Publication Bollettino della Societa italiana di biologia sperimentale Abbreviated Journal Boll Soc Ital Biol Sper
Volume (down) 66 Issue 11 Pages 1089-1096
Keywords Animals; *Animals, Wild/physiology/psychology; Environment; Female; *Horses/physiology/psychology; Italy; Male; Population Density; Sexual Behavior, Animal; *Social Behavior; Social Dominance; Water
Abstract In this paper some considerations on the environment of the 42 Kmq of the volcanic-basaltic Giara tableland are discussed. Conditioning by the environment and its effect on the distribution of a population of 712 horses is illustrated in view of their social and behavioural organization.
Address Istituto di Fisiologia Generale e Speciale, Universita di Sassari
Corporate Author Thesis
Publisher Place of Publication Editor
Language Italian Summary Language Original Title Introduzione all'organizzazione sociale e comportamentale dei cavallini sulla Giara (Sardegna): distribuzione ed aggregazione
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0037-8771 ISBN Medium
Area Expedition Conference
Notes PMID:2095819 Approved no
Call Number refbase @ user @ Serial 673
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Author Judge, P.G.; de Waal, F.B.
Title Intergroup grooming relations between alpha females in a population of free-ranging rhesus macaques Type Journal Article
Year 1994 Publication Folia primatologica; international journal of primatology Abbreviated Journal Folia Primatol (Basel)
Volume (down) 63 Issue 2 Pages 63-70
Keywords Animals; Animals, Wild; Female; *Grooming; Macaca mulatta/*psychology; Male; Population Density; *Social Behavior
Abstract Intergroup affiliation among female rhesus macaques, Macaca mulatta, was examined in the captive free-ranging colony of Morgan Island, S.C., USA. The provisioned colony has many social groups (35) and is maintained at a relatively high population density (21 animals/ha) with a relatively low adult male to female ratio (1:8.8). Focal and ad libitum samples were collected on 32 adults (3 males and 29 females) from two groups. Although infrequent, grooming was observed between adult females from different groups, and alpha females were the main participants in these interactions. Colony records indicated that none of the intergroup grooms was between females formerly from a common group. Relations between familiar neighboring groups may be maintained by a combination of both affiliative and aggressive behavior.
Address Yerkes Regional Primate Research Center, Lawrenceville, Ga 30243
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0015-5713 ISBN Medium
Area Expedition Conference
Notes PMID:7813977 Approved no
Call Number refbase @ user @ Serial 208
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Author Kralj-Fiser, S.; Scheiber, I.B.R.; Blejec, A.; Moestl, E.; Kotrschal, K.
Title Individualities in a flock of free-roaming greylag geese: behavioral and physiological consistency over time and across situations Type Journal Article
Year 2007 Publication Hormones and Behavior Abbreviated Journal Horm Behav
Volume (down) 51 Issue 2 Pages 239-248
Keywords Animals; Behavior, Animal/*physiology; Corticosterone/metabolism; Feces; Female; Geese/*physiology; Individuality; Male; Personality/*physiology; Population Density; Reproducibility of Results; Seasons; *Social Behavior; Social Environment; Testosterone/*metabolism
Abstract The concept of personality implies individual differences in behavior and physiology that show some degree of repeatability/consistency over time and across contexts. Most studies of animal personality, particularly studies of individuals' variation in physiological mechanisms, have been conducted on selected individuals in controlled conditions. We attempted to detect consistent behaviors as well as physiological patterns in greylag ganders (Anser anser) from a free-roaming flock living in semi-natural conditions. We tested 10 individuals repeatedly, in a handling trial, resembling tests for characterization of “temperaments” in captive animals. We recorded the behavior of the same 10 individuals during four situations in the socially intact flock: (1) a “low density feeding condition”, (2) a “high density feeding condition”, (3) a “low density post-feeding situation” and (4) while the geese rested. We collected fecal samples for determination of excreted immuno-reactive corticosterone (BM) and testosterone metabolites (TM) after handling trials, as well as the “low density feeding” and the “high density feeding” conditions. BM levels were very highly consistent over the repeats of handling trials, and the “low density feeding condition” and tended to be consistent over the first two repeats of the “high density feeding condition”. Also, BM responses tended to be consistent across contexts. Despite seasonal variation, there tended to be inter-test consistency of TM, which pointed to some individual differences in TM as well. Aggressiveness turned out to be a highly repeatable trait, which was consistent across social situations, and tended to correlate with an individual's resistance during handling trials. Also, “proximity to the female partner” and “sociability” – the average number of neighboring geese in a close distance while resting – were consistent. We conclude that aggressiveness, “affiliative tendencies” and levels of excreted corticosterone and testosterone metabolites may be crucial factors of personality in geese.
Address University of Ljubljana, Biotechnical faculty, Slovenia. simona.kralj@guest.arnes.si
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-506X ISBN Medium
Area Expedition Conference
Notes PMID:17196200 Approved no
Call Number Equine Behaviour @ team @ Serial 4189
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Author Nicol, C.J.; Brown, S.N.; Glen, E.; Pope, S.J.; Short, F.J.; Warriss, P.D.; Zimmerman, P.H.; Wilkins, L.J.
Title Effects of stocking density, flock size and management on the welfare of laying hens in single-tier aviaries Type Journal Article
Year 2006 Publication British poultry science Abbreviated Journal Br Poult Sci
Volume (down) 47 Issue 2 Pages 135-146
Keywords Animal Husbandry/*methods; *Animal Welfare; Animals; Body Constitution/*physiology; Chickens/*physiology; Crowding; Feathers; Female; *Housing, Animal/standards; Mortality; Organ Size; Oviposition/physiology; Population Density; Population Dynamics; Random Allocation
Abstract Management practices, stocking rate and flock size may affect laying hen welfare but there have been few replicated studies in commercial non-cage systems that investigate this. This study used a broad range of physical and physiological indicators to assess the welfare of hens in 36 commercial flocks. Six laying period treatments were examined with each treatment replicated 6 times. It was not possible to randomly allocate treatments to houses, so treatment and house were largely confounded. Three stocking rates were compared: 7 birds/m(2) (n = 2450), 9 birds/m(2) (n = 3150) and 12 birds/m(2) in either small (n = 2450) or large (n = 4200) flocks. In addition, at 12 birds/m(2), in both small and large flocks, birds were subjected to either standard (SM) or modified (MM) management. MM flocks had nipple drinkers and no nest-box lights. Bone strength, fracture incidence, heterophil:lymphocyte (H:L) ratio, live weight, organ weights, serum creatine, serum osmolality, muscle pH and faecal corticosterone were measured on samples of birds at the end of the rearing period and at the end of lay. During the laying period, mortality, production and integument condition were recorded at regular intervals. Birds housed at 9 birds/m(2) had higher mortality than birds housed at 12 birds/m(2) by the end of lay, but not higher than birds housed at 7 birds/m(2). Birds housed at 7 and 9 birds/m(2) had lower percent liver weight, and worse plumage condition than most of the 12 bird/m(2) treatments. Modified management tended to improve plumage condition. There were no clear effects of flock size on the welfare indicators recorded. At the end of the rearing period fracture incidence was almost negligible and H:L ratio was within a normal range. By the end of lay fracture incidence was 60% and H:L ratio was high, with no treatment effect for either measure. This, together with information on faecal corticosterone, feather loss and mortality, suggests that the welfare of birds in all treatments was relatively poor by the end of lay.
Address School of Veterinary Science, University of Bristol, Langford House, Langford BS40 5DU and ADAS Gleadthorpe, Meden Vale, Mansfield, Notts NG20 9PF, England. c.j.nicol@bristol.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0007-1668 ISBN Medium
Area Expedition Conference
Notes PMID:16641024 Approved no
Call Number refbase @ user @ Serial 65
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Author Albentosa, M.J.; Kjaer, J.B.; Nicol, C.J.
Title Strain and age differences in behaviour, fear response and pecking tendency in laying hens Type Journal Article
Year 2003 Publication British poultry science Abbreviated Journal Br Poult Sci
Volume (down) 44 Issue 3 Pages 333-344
Keywords Age Factors; Aggression/*physiology; Animal Husbandry; Animals; *Behavior, Animal; Breeding; Chickens/genetics/*physiology; Fear/*physiology; Feathers/*injuries; Female; Housing, Animal; Population Density; Social Behavior
Abstract 1. Behaviours associated with a high or low tendency to feather peck could be used as predictors of feather pecking behaviour in selective breeding programmes. This study investigated how strain and age at testing influenced responses in behavioural tests. 2. Four layer-type strains (ISA Brown, Columbian Blacktail, Ixworth and a high feather pecking (HP) and a low feather pecking (LP) line of White Leghorn) were reared in 6 same-strain/line pens of 8 birds from one day old. Birds in half the pens were given an open field test, a novel object test and a test with loose feather bundles between 4 and 12 weeks of age and a tonic immobility (TI) test at 13 weeks of age. All pens were tested with fixed feather bundles at 26 weeks, and undisturbed behaviour in the home pens was videoed at 1 and 27 weeks of age. Daily records of plumage damage were used as an indicator of feather pecking activity in the home pens. 3. Strain did not influence novel object test, open field test or loose feather test behaviour, although age effects in all three tests indicated a reduction in fearfulness and/or an increase in exploratory behaviour with increasing age. 4. White Leghorns showed longer TI durations than the other strains but less pecking at fixed feather bundles than ISA Browns and Columbian Blacktails. 5. There were few associations between behaviour in the 5 different tests, indicating that birds did not have overall behavioural traits that were consistent across different contexts. This suggests hens cannot easily be categorised into different behavioural 'types', based on their test responses and casts doubt on the usefulness of tests as predictors of feather pecking.
Address Centre for Behavioural Biology, Division of Farm Animal Science, University of Bristol, Langford, Bristol, England. MAlbentosa@lincoln.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0007-1668 ISBN Medium
Area Expedition Conference
Notes PMID:13677322 Approved no
Call Number refbase @ user @ Serial 80
Permanent link to this record