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| Author | Dellert, B.; Ganslosser, U. | ||||
| Title | Experimental alterations of food distribution in two species of captive equids (Equus burchelli and E. hemionus kulan) | Type | Journal Article | ||
Year  |
1997 | Publication | Ethology Ecology & Evolution (EEE) | Abbreviated Journal | Ethol Ecol Evol |
| Volume | 9 | Issue | 1 | Pages | 1-17 |
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| Abstract | n one group each of Plains zebra (six mares, one foal, one subadult) and Asiatic wild asses (seven mares, two foals) at Nuremberg Zoo, food distribution was experimentally changed from clumped (all food in one standard hay rack) to dispersed (one heap per animal). Both groups were characterized by different social structures, which basically remained during the experiment. Plains zebras had an individually structured system of social relationships in a dominance order, wild asses a more egalitarian system without clear-cut rank differences and low frequencies of agonistic interactions. Access to food accordingly was individually (but consistently) different for zebra mares, almost equal for wild ass mares. During the dispersed feeding situation frequencies of agonistic interactions in both species decreased (however non-significantly), individual distances increased but mares also frequently ''visited'' each others' heaps. Feeding time increased for all wild ass mares. Some individuals (in both groups) behaved ''against the trend'' in agonistic behaviour. The results are discussed with regard to food distribution for ungulates in general, and equid social systems. | ||||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 2292 | ||
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| Author | Monard, A.-M.; Duncan, P.; Fritz, H.; Feh, C. | ||||
| Title | Variations in the birth sex ratio and neonatal mortality in a natural herd of horses | Type | Journal Article | ||
| Year |
1997 | Publication | Behavioral Ecology and Sociobiology | Abbreviated Journal | Behav. Ecol. Sociobiol. |
| Volume | 41 | Issue | 4 | Pages | 243-249 |
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| Abstract | Variations in birth sex ratios and sex differences in juvenile mortality occur in a number of mammalian species, and in many cases have been linked to resource availability. Most of these biases in offspring sex ratios concern polygynous species with pronounced sexual dimorphism, and where females only are philopatric. Data on species with unusual life-history strategies, such as slight sexual dimorphism or dispersal by both sexes, are of particular interest. In this study of a natural herd of horses (Equus caballus) which experienced an eruptive cycle, and therefore a period of nutritional stress, male offspring had higher neonatal mortality rates in nutritionally poor years than in good ones, whereas “year quality” had no effect on the mortality of female offspring; year quality could therefore be used by mares as predictor of sex-specific offspring survival. We show that the environmental conditions that predicted lower survival of males were negatively related to their production: the birth sex ratio the following year was female-biased; and mares were less likely to produce a son when they had produced a son the preceding year. There was no significant effect of mother's parity, age or rank, or the timing of conception or birth on offspring sex ratios. The mechanism leading to biases in the birth sex ratio could have been the loss of male embryos by mares that did not foal. As there was no evidence for selective abortion of male foetuses in females that did foal the next year, it is not necessary to invoke maternal adjustment, though this remains a possibility. Finally, there was a suggestion that male offspring were more costly to raise than females, since mothers that reared a son in poor years tended to experience an increase in the interbirth interval between their two subsequent offspring. | ||||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 2388 | ||
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| Author | Giraldeau, Luc-Alain | ||||
| Title | The ecology of information use | Type | Book Chapter | ||
| Year |
1997 | Publication | Behavioural ecology : an evolutionary approach | Abbreviated Journal | |
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| Publisher | Blackwell Science | Place of Publication | Cambridge, Mass. | Editor | Krebs, J.R.; Davies, N.B. |
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| ISSN | ISBN | 0865427313 9780865427310 | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ 35114973 | Serial | 4277 | ||
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| Author | Sterck, E.; Watts, D.; van Schaik, C. | ||||
| Title | The evolution of female social relationships in nonhuman primates | Type | Journal Article | ||
| Year |
1997 | Publication | Behavioral Ecology and Sociobiology | Abbreviated Journal | Behav. Ecol. Sociobiol. |
| Volume | 41 | Issue | 5 | Pages | 291-309 |
| Keywords | ecology; matrilocal; primate; social; theory | ||||
| Abstract | Considerable interspeci®c variation in female social relationships occurs in gregarious primates, particularly with regard to agonism and cooperation between females and to the quality of female relationships with males. This variation exists alongside variation in female philopatry and dispersal. Socioecological theories have tried to explain variation in female-female social relationships from an evolutionary perspective focused on ecological factors, notably predation and food distribution. According to the current ``ecological model'', predation risk forces females of most diurnal primate species to live in groups; the strength of the contest component of competition for resources within and between groups then largely determines social relationships between females. Social elationships among gregarious females are here characterized as DispersalEgalitarian, Resident-Nepotistic, Resident-Nepotistic-Tolerant, or Resident-Egalitarian. This ecological model has successfully explained i€erences in the occurrence of formal submission signals, decided dominance relation ships, coalitions and female philopatry. Group size and female rank generally a€ect female reproduction success as the model predicts, and studies of closely related species in di€erent ecological circumstances underscore the importance of the model. Some cases, however, can only be explained when we extend the model to incorporate the e€ects of infanticide risk and habitat saturation. We review evidence in support of the ecological model and test the power of alternative models that invoke between-group competition, forced female philopatry, demographic female recruitment, male interventions into female aggression, and male harassment. Not one of these models can replace the ecological model, which already encompasses the between-group competition. Currently the best model, which explains several phenomena that the ecological model does not, is a ``socioecological model'' based on the combined importance of ecological factors, habitat saturation and infanticide avoidance. We note some points of similarity and divergence with other mammalian taxa; these remain to be explored in detail. |
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 5227 | ||
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| Author | Wanker, R.; Apcin, J.; Jennerjahn, B.; Waibel, B. | ||||
| Title | Discrimination of different social companions in spectacled parrotlets ( Forpus conspicillatus ): evidence for individual vocal recognition | Type | Journal Article | ||
| Year |
1998 | Publication | Behavioral Ecology and Sociobiology | Abbreviated Journal | Behav. Ecol. Sociobiol. |
| Volume | 43 | Issue | 3 | Pages | 197-202 |
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| Abstract | Abstract: Individual recognition is generally assumed to be a prerequisite for establishing and maintaining a complex social system. Indeed, there is good evidence that highly social species have complex systems of vocal communication with individual recognition by acoustic cues. In this study, we provide experimental evidence that vocal class and individual recognition is present in a non-passerine bird, the spectacled parrotlet (Forpus conspicillatus). Spectacled parrotlets live in a complex system of social relationships. Soon after fledging, the young establish close sibling relationships which are important for successful socialization, pairing and reproduction. In a series of playback experiments we tested if spectacled parrotlets use contact calls for vocal recognition. The results showed that spectacled parrotlets discriminate between the contact calls of different social categories. Adult birds preferred to respond to the contact calls of their mates. Subadult individuals recognized the contact calls of their siblings. During the period of pair bond formation, the affiliative contacts to the siblings decrease, but the parrotlets continue to respond to the calls of their siblings. This is the first evidence that vocal sibling recognition might outlast the period of strong sibling interaction and extends into the period of pair bond formation. In cases of mate loss or divorce, the acoustic contact to their siblings might facilitate the re-establishment of close sibling relationships. | ||||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 4571 | ||
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| Author | Connor, R.C.; Mann, J.; Tyack, P.L.; Whitehead, H. | ||||
| Title | Social evolution in toothed whales | Type | Journal Article | ||
| Year |
1998 | Publication | Trends in Ecology & Evolution | Abbreviated Journal | Trends. Ecol. Evol |
| Volume | 13 | Issue | 6 | Pages | 228-232 |
| Keywords | odontocetes; toothed whales; social evolution; communication; bottlenose dolphins; sperm whales; long-term studies; foraging | ||||
| Abstract | Two contrasting results emerge from comparisons of the social systems of several odontocetes with terrestrial mammals. Researchers have identified remarkable convergence in prominent features of the social systems of odontocetes such as the sperm whale and bottlenose dolphin with a few well-known terrestrial mammals such as the elephant and chimpanzee. In contrast, studies on killer whales and Baird's beaked whale reveal novel social solutions to aquatic living. The combination of convergent and novel features in odontocete social systems promise a more general understanding of the ecological determinants of social systems in both terrestrial and aquatic habitats, as well as the relationship between relative brain size and social evolution. | ||||
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| ISSN | 0169-5347 | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 4789 | ||
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| Author | Matsumura, S.; Kobayashi, T. | ||||
| Title | A game model for dominance relations among group-living animals | Type | Journal Article | ||
| Year |
1998 | Publication | Behavioral Ecology and Sociobiology | Abbreviated Journal | Behav. Ecol. Sociobiol. |
| Volume | 42 | Issue | 2 | Pages | 77-84 |
| Keywords | Dominance – Hawk-dove games – Resource-holding potential – Asymmetry – Evolutionarily stable strategy | ||||
| Abstract | Abstract We present here an attempt to understand behaviors of dominant individuals and of subordinate individuals as behavior strategies in an asymmetric “hawk-dove” game. We assume that contestants have perfect information about relative fighting ability and the value of the resource. Any type of asymmetry, both relevant to and irrelevant to the fighting ability, can be considered. It is concluded that evolutionarily stable strategies (ESSs) depend on the resource value (V), the cost of injury (D), and the probability that the individual in one role will win (x). Different ESSs can exist even when values of V, D, and x are the same. The characteristics of dominance relations detected by observers may result from the ESSs that the individuals are adopting. The model explains some characteristics of dominance relations, for example, the consistent outcome of contests, the rare occurrence of escalated fights, and the discrepancy between resource holding potential (RHP) and dominance relations, from the viewpoint of individual selection. | ||||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 5102 | ||
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| Author | Czaran, T. | ||||
| Title | Game theory and evolutionary ecology: Evolutionary Games & Population Dynamics by J. Hofbauer and K. Sigmund, and Game Theory & Animal Behaviour, edited by L.A. Dugatkin and H.K. Reeve | Type | Journal Article | ||
| Year |
1999 | Publication | Trends in Ecology & Evolution | Abbreviated Journal | Trends. Ecol. Evol |
| Volume | 14 | Issue | 6 | Pages | 246-247 |
| Keywords | Game theory; Evolutionary ecology; Population dynamics; Ethology | ||||
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| Notes | Approved | no | |||
| Call Number | refbase @ user @ | Serial | 485 | ||
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| Author | Taberlet, P.; Waits, L.P.; Luikart, G. | ||||
| Title | Noninvasive genetic sampling: look before you leap | Type | Journal Article | ||
| Year |
1999 | Publication | Trends in Ecology & Evolution | Abbreviated Journal | Trends Ecol. Evol |
| Volume | 14 | Issue | 8 | Pages | 323-327 |
| Keywords | Hairs; Feces; Feathers; Allelic dropout; Individual identification; Conservation genetics; Behavioural ecology; Pilot study; Microsatellites; Probability of identity | ||||
| Abstract | Noninvasive sampling allows genetic studies of free-ranging animals without the need to capture or even observe them, and thus allows questions to be addressed that cannot be answered using conventional methods. Initially, this sampling strategy promised to exploit fully the existing DNA-based technology for studies in ethology, conservation biology and population genetics. However, recent work now indicates the need for a more cautious approach, which includes quantifying the genotyping error rate. Despite this, many of the difficulties of noninvasive sampling will probably be overcome with improved methodology. | ||||
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| ISSN | 0169-5347 | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 6573 | ||
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| Author | Shettleworth, S.J. | ||||
| Title | Cognitive ecology: field or label? | Type | Journal Article | ||
| Year |
2000 | Publication | Trends in Ecology & Evolution | Abbreviated Journal | Trends. Ecol. Evol |
| Volume | 15 | Issue | 4 | Pages | 161 |
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| Address | Depts of Psychology and Zoology, University of Toronto, Toronto, Ontario, Canada M5S 3G3 | ||||
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| Language | English | Summary Language | Original Title | ||
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| ISSN | 0169-5347 | ISBN | Medium | ||
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| Notes | PMID:10717686 | Approved | no | ||
| Call Number | refbase @ user @ | Serial | 373 | ||
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