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| Author | Pearce, G.P.; May-Davis, S.; Greaves, D. | ||||
| Title | Femoral asymmetry in the Thoroughbred racehorse | Type | Journal Article | ||
| Year | 2005 | Publication  |
Australian Veterinary Journal | Abbreviated Journal | Aust Vet J |
| Volume | 83 | Issue | 6 | Pages | 367-370 |
| Keywords | Animals; Cumulative Trauma Disorders/pathology/*veterinary; Femur/*pathology; Horse Diseases/*pathology/physiopathology; Horses; Locomotion; Physical Conditioning, Animal/*physiology | ||||
| Abstract | OBJECTIVE: To investigate the occurrence of geometrical asymmetries in the macro-architecture of left and right femurs from Thoroughbred racehorses previously used in competitive training and racing in New South Wales, Australia. METHODS: Detailed postmortem measurements were made of 37 characteristics of left and right femurs from eleven Thoroughbred racehorses euthanased for reasons unrelated to the study. Measurements focused on articulating surfaces and sites of attachment of muscles and ligaments known to be associated with hindlimb locomotion. RESULTS: Five measurements were significantly larger in left compared to right femurs (P < 0.05). The regions showing significant differences between left and right limbs were proximal cranial and overhead medio-lateral widths, greater trochanter depth, depth of the fovea in the femoral head and distal inter-epicondylar width. CONCLUSION: The left-right differences in femoral morphology were associated with sites of muscle and ligament attachment known to be involved with hindlimb function in negotiating turns. These differences may be the result of selection pressure for racing performance on curved race tracks and/or adaptations related to asymmetrical loading of the outside hindlimb associated with repeated negotiation of turns on such tracks. | ||||
| Address | Faculty of Rural Management, University of Sydney, Leeds Parade, Orange, New South Wales 2800. gpp28@cam.ac.uk | ||||
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| Language | English | Summary Language | Original Title | ||
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| ISSN | 0005-0423 | ISBN | Medium | ||
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| Notes | PMID:15986917 | Approved | no | ||
| Call Number | Equine Behaviour @ team @ | Serial | 4036 | ||
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| Author | Cant, M.A.; Field, J. | ||||
| Title | Helping effort in a dominance hierarchy | Type | Journal Article | ||
| Year | 2005 | Publication |
Behavioral Ecology | Abbreviated Journal | Behav. Ecol. |
| Volume | 16 | Issue | 4 | Pages | 708-715 |
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| Abstract | In many cooperatively breeding species, group members form a dominance hierarchy or queue to inherit the position of breeder. Models aimed at understanding individual variation in helping behavior, however, rarely take into account the effect of dominance rank on expected future reproductive success and thus the potential direct fitness costs of helping. Here we develop a kin-selection model of helping behavior in multimember groups in which only the highest ranking individual breeds. Each group member can invest in the dominant's offspring at a cost to its own survivorship. The model predicts that lower ranked subordinates, who have a smaller probability of inheriting the group, should work harder than higher ranked subordinates. This prediction holds regardless of whether the intrinsic mortality rate of subordinates increases or decreases with rank. The prediction does not necessarily hold, however, where the costs of helping are higher for lower ranked individuals: a situation that may be common in vertebrates. The model makes two further testable predictions: that the helping effort of an individual of given rank should be lower in larger groups, and the reproductive success of dominants should be greater where group members are more closely related. Empirical evidence for these predictions is discussed. We argue that the effects of rank on stable helping effort may explain why attempts to correlate individual helping effort with relatedness in cooperatively breeding species have met with limited success. | ||||
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| Notes | 10.1093/beheco/ari051 | Approved | no | ||
| Call Number | refbase @ user @ | Serial | 760 | ||
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| Author | Vahl, W.K.; Lok, T.; van der Meer, J.; Piersma, T.; Weissing, F.J. | ||||
| Title | Spatial clumping of food and social dominance affect interference competition among ruddy turnstones | Type | Journal Article | ||
| Year | 2005 | Publication |
Behavioral Ecology | Abbreviated Journal | Behav. Ecol. |
| Volume | 16 | Issue | 5 | Pages | 834-844 |
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| Abstract | In studying the success of foraging animals, studies of interference competition have put emphasis on effects of competitor density, whereas studies of resource defense have focused on the effects of the spatial distribution of food within patches. Very few studies have looked at both factors simultaneously, that is, determined whether the effects of competitor density on foraging success depend on the spatial distribution of food. We studied the behavior and the foraging success of ruddy turnstones (Arenaria interpres) using an experiment in which we varied both the presence of a competitor and the food distribution. Because turnstones may differ strongly in their relative dominance status, we also experimentally varied the foragers' relative dominance status. We found that the presence of a competitor only reduced the foraging success of subordinate birds foraging at the clumped food distribution. At this condition, dominant and subordinate birds differed markedly in their foraging success. Contrary to our expectations, we did not observe more agonistic behavior at the clumped food distribution. This indicates that the amount of agonistic behavior observed may be a bad indicator of interference effects. These findings have specific implications for models of interference competition. Most notably they show that the effects of competitor density on agonistic behavior and foraging success may well depend on the spatial distribution of food and the foragers' relative dominance status. Additionally, our results suggest that social dominance will not be fully understood without considering long-term processes such as the formation and maintenance of social dominance hierarchies. | ||||
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| Notes | 10.1093/beheco/ari067 | Approved | no | ||
| Call Number | refbase @ user @ | Serial | 761 | ||
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| Author | Krama, T. [1]; Krams, I. [2] | ||||
| Title | Cost of mobbing call to breeding pied flycatcher, Ficedula hypoleuca | Type | Journal Article | ||
| Year | 2005 | Publication |
Behavioral Ecology | Abbreviated Journal | Behav. Ecol. |
| Volume | 16 | Issue | Pages | 37-40 | |
| Keywords | ntipredator behavior, Ficedula hypoleuca, mobbing calls, mobbing costs, pied flycatcher. | ||||
| Abstract | Mobbing signals advertise the location of a stalking predator to all prey in an area and recruit them into the inspection aggregation. Such behavior usually causes the predator to move to another area. However, mobbing calls could be eavesdropped by other predators. Because the predation cost of mobbing calls is poorly known, we investigated whether the vocalizations of the mobbing pied flycatcher, Ficedula hypoleuca, a small hole nesting passerine, increase the risk of nest predation. We used mobbing calls of pied flycatchers to examine if they could lure predators such as the marten, Martes martes. This predator usually hunts by night and may locate its mobbing prey while resting nearby during the day. Within each of 56 experimental plots, from the top of one nest-box we played back mobbing sounds of pied flycatchers, whereas blank tapes were played from the top of another nest-box. The trials with mobbing calls were carried out before sunset. We put pieces of recently abandoned nests of pied flycatchers and a quail, Coturnix coturnix, egg into each of the nest-boxes. Nest-boxes with playbacks of mobbing calls were depredated by martens significantly more than were nest-boxes with blank tapes. The results of the present study indicate that repeated conspicuous mobbing calls may carry a significant cost for birds during the breeding season. | ||||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 4092 | ||
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| Author | Kavaliers, M.; Colwell, D.D.; Choleris, E. | ||||
| Title | Kinship, familiarity and social status modulate social learning about “micropredators” (biting flies) in deer mice | Type | Journal Article | ||
| Year | 2005 | Publication |
Behavioral Ecology and Sociobiology | Abbreviated Journal | Behav. Ecol. Sociobiol. |
| Volume | 58 | Issue | 1 | Pages | 60-71 |
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| Notes | Approved | no | |||
| Call Number | refbase @ user @ | Serial | 710 | ||
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| Author | Gibson, B.M.; Shettleworth, S.J. | ||||
| Title | Place versus response learning revisited: tests of blocking on the radial maze | Type | Journal Article | ||
| Year | 2005 | Publication |
Behavioral neuroscience | Abbreviated Journal | Behav Neurosci |
| Volume | 119 | Issue | 2 | Pages | 567-586 |
| Keywords | Animals; *Association Learning; Male; *Maze Learning; Memory; Rats; Rats, Long-Evans; Reproducibility of Results | ||||
| Abstract | Neurobiological and behavioral research indicates that place learning and response learning occur simultaneously, in parallel. Such findings seem to conflict with theories of associative learning in which different cues compete for learning. The authors conducted place+response training on a radial maze and then tested place learning and response learning separately by reconfiguring the maze in various ways. Consistent with the effects of manipulating place and response systems in the brain (M. G. Packard & J. L. McGaugh, 1996), well-trained rats showed strong place learning and strong response learning. Three experiments using associative blocking paradigms indicated that prior response learning interferes with place learning. Blocking and related tests can be used to better understand how memory systems interact during learning. | ||||
| Address | Department of Psychology, University of New Hampshire, Durham, NH 03824-3567, USA. bgibson@cisunix.unh.edu | ||||
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| Language | English | Summary Language | Original Title | ||
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| ISSN | 0735-7044 | ISBN | Medium | ||
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| Notes | PMID:15839803 | Approved | no | ||
| Call Number | refbase @ user @ | Serial | 362 | ||
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| Author | Hemelrijk,C. K.; Wantia,J.; Gygax,L. | ||||
| Title | The construction of dominance order: comparing performance of five methods using an individual-based model | Type | Journal Article | ||
| Year | 2005 | Publication |
Behaviour | Abbreviated Journal | Behaviour |
| Volume | 142 | Issue | 8 | Pages | 1043-1064 |
| Keywords | dominance order, ranking method, agent-based model, statistical method, aggression | ||||
| Abstract | In studies of animal behaviour investigators correlate dominance with all kinds of behavioural variables, such as reproductive success and foraging success. Many methods are used to produce a dominance hierarchy from a matrix reflecting the frequency of winning dominance interactions. These different methods produce different hierarchies. However, it is difficult to decide which ranking method is best. In this paper, we offer a new procedure for this decision: we use an individual-based model, called DomWorld, as a test-environment. We choose this model, because it provides access to both the internal dominance values of artificial agents (which reflects their fighting power) and the matrix of winning and losing among them and, in addition, because its behavioural rules are biologically inspired and its group-level patterns resemble those of real primates. We compare statistically the dominance hierarchy based on the internal dominance values of the artificial agents with the dominance hierarchy produced by ranking individuals by (a) their total frequency of winning, (b) their average dominance index, (c) a refined dominance index, the David`s score, (d) the number of subordinates each individual has and (e) a ranking method based on maximizing the linear order of the hierarchy. Because dominance hierarchies may differ depending on group size, type of society, and the interval of study, we compare these ranking methods for these conditions.We study complete samples as well as samples randomly chosen to resemble the limitations of observing real animals. It appears that two methods of medium complexity (the average dominance index and David`s score) lead to hierarchical orders that come closest to the hierarchy based on internal dominance values of the agents. We advocate usage of the average dominance index, because of its computational simplicity. |
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| Notes | Approved | no | |||
| Call Number | refbase @ user @ | Serial | 445 | ||
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| Author | Digweed, Shannon M.; Fedigan, Linda M.; Rendall, Drew | ||||
| Title | Variable specificity in the anti-predator vocalizations and behaviour of the white-faced capuchin, Cebus capucinus | Type | Journal Article | ||
| Year | 2005 | Publication |
Behaviour | Abbreviated Journal | Behaviour |
| Volume | 142 | Issue | 8 | Pages | 997-1021 |
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| Abstract | (Accepted: 23 June 2005) Summary Much research in animal communication is aimed at understanding the functional design features of animal vocal signals. Our detailed analyses of the vocalizations and behavioural responses elicited in white-faced capuchins by predators and other disturbances point to two call variants that differ modestly in their acoustic structure and that are accompanied by functionally distinct behavioural responses. The first variant is given exclusively to avian predators and is almost invariably accompanied by the monkeys immediate descent from the treetops where it is most vulnerable; therefore, we label this call variant the aerial predator alarm?. The second variant, that differs only slightly but noticeably from the first, is given to a wide range of snakes and mammals, including a range of species that represent no predatory threat to the monkeys. This second call is also associated with more variable responses from calling monkeys, from delayed retreat from the source of disturbance, to active approach, inspection, and sometimes mobbing of the animal involved. We therefore label this variant more generally as an “alerting call”. Although some other primate species show a more diverse system of anti-predator calls, and the capuchins themselves may yet be found to produce a greater variety of calls, a system of two call variants with varying degrees of predator specificity and behavioural response is not uncommon among primates and appears functionally appropriate for capuchins. The basic structure of the alerting call allows conspecific listeners to localize the caller and the source of disturbance readily, thereby allowing listeners to approach and assist in mobbing in cases where the disturbance warrants it, or to avoid the area in cases where the disturbance is identified as a predatory threat. Conversely, the aerial predator alarm is inherently less localizable and therefore conveys the |
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| Notes | Approved | no | |||
| Call Number | refbase @ user @ | Serial | 547 | ||
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| Author | Robbins, M.M.; Robbins, A.M.; Gerald-Steklis, N.; Steklis, H.D. | ||||
| Title | Long-term dominance relationships in female mountain gorillas: strength, stability and determinants of rank | Type | Journal Article | ||
| Year | 2005 | Publication |
Behaviour | Abbreviated Journal | Behaviour |
| Volume | 142 | Issue | 6 | Pages | 779-809 |
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| Abstract | A common practice in studies of social animals is to rank individuals according to dominance status, which has been shown to influence access to limited resources and stability of social relationships, and may in turn correlate with reproductive success. According to the socioecological model for primates, most female dominance relationships are either nepotistic or virtually undetectable (egalitarian), with nepotistic species being philopatric, and dispersing females being egalitarian. Female mountain gorillas (Gorilla beringei beringei) disperse, and they have been characterized as being egalitarian, but previous studies have not examined their dominance relationships from a long-term perspective. We evaluated 15 matrices of displacement/supplantation interactions that spanned 30 years of observations in the Virunga Volcanoes region, and included 51 female mountain gorillas in six groups. Only 4% of displacements were directed against higher ranking females, and when matrices had less than 5% unknown dyads, linearity indices were consistently greater than 0.95. Therefore, previous results suggesting undetectable dominance relationships may have reflected an insufficient quantity of data for this species, rather than actual nonlinearity in its hierarchies. Dominance depended on age and group tenure rather than nepotism, yet some females maintained a high ranking for most of adulthood (15-25 years). Most rank shifts occurred through changes in group composition, rather than switches in established relationships. These results fit within growing evidence for linear individualistic hierarchies in some primates, often coupled with dispersal, as commonly found in ungulates. In light of these results, we propose that the dominance relationships of female mountain gorilla are best characterized as “Dispersal-Individualistic” instead of the previously suggested “Dispersal-Egalitarian”. | ||||
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| Call Number | Equine Behaviour @ team @ | Serial | 2164 | ||
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| Author | Stevens, J.; Vervaecke, H.; de Vries, H.; Van Elsacker, L. | ||||
| Title | The influence of the steepness of dominance hierarchies on reciprocity and interchange in captive groups of bonobos (Pan paniscus) | Type | Journal Article | ||
| Year | 2005 | Publication |
Behaviour | Abbreviated Journal | Behaviour |
| Volume | 142 | Issue | 7 | Pages | 941-960 |
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| Abstract | Biological market models explain variability in reciprocity and interchange between groups. In groups with a shallow dominance gradient, grooming will be mostly exchanged for itself (i.e. exchange will occur). In groups with steep dominance hierarchies, interchange is expected: individuals will groom higher ranking individuals to get access to limited resources or commodities such as support in conflicts, and grooming will be traded for these commodities. We examine patterns of reciprocity in grooming and support, and of interchange of grooming for support or for tolerance in six captive groups of bonobos. We test whether differences between groups in patterns of reciprocity and interchange can be attributed to differences in a measure of steepness of dominance hierarchies, which is based on dyadic agonistic interactions. We found that grooming was reciprocal in some, but not all groups. Support was highly reciprocal, but this was a side effect of dominance in most groups. Interchange between grooming and support was observed in some groups. Corroborating earlier findings, this was a side effect of individuals preferring high ranking individuals as grooming and support partners, possibly because these high-ranking individuals provide more efficient support in conflicts. There was no evidence for interchange of grooming for tolerance. Variability in grooming reciprocity was explained by differences in steepness of dominance hierarchies, as predicted by the biological market models. In groups with a shallow dominance hierarchy, grooming was more reciprocal. This was not true for reciprocity in support. There was some evidence that individuals groomed dominants more frequently in groups with a steep dominance hierarchy. The variation in interchange relations between grooming and support did not depend on the steepness of dominance hierarchies. We suggest that grooming in itself is a valuable commodity in bonobos, especially under captive conditions, which can be exchanged reciprocally. Bonobos may interchange grooming for another value equivalent, with food sharing as a very likely candidate. This interchange effects seem more dependent on potential to monopolise food than on steepness of dominance hierarchies per se. | ||||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 2194 | ||
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