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Stevens, J., Vervaecke, H., de Vries, H., & Van Elsacker, L. (2005). The influence of the steepness of dominance hierarchies on reciprocity and interchange in captive groups of bonobos (Pan paniscus). Behaviour, 142(7), 941–960.
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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Christensen, J. W., Keeling, L. J., & Nielsen, B. L. (2005). Responses of horses to novel visual, olfactory and auditory stimuli. Appl. Anim. Behav. Sci., 93(1-2), 53–65.
Abstract: Responses of horses towards fear-eliciting stimuli can have important consequences for both human and horse safety. This experiment was designed to investigate behavioural and heart rate (HR) responses of horses to novel visual, auditory and olfactory stimuli. Twenty-four 2-year-old, previously unhandled, stallions were habituated to receive a food reward from a container in a test arena. Each horse was exposed to three 2 min tests in a balanced design where in addition to the feed container, either a traffic cone (visual test), white noise (auditory test) or eucalyptus oil applied to the inside of the container (olfactory test) were used as the novel stimuli. Compared to the control, less time was spent eating during all tests. There was no difference in locomotion activity in the different test situations, but presentation of the novel visual and auditory stimuli elicited significantly increased HR responses in the horses, compared to their response to the arena without novel stimuli (control), whereas there was no increase in HR response to the olfactory stimulus. However, during the olfactory test, the horses had an increased number of eating bouts and became more vigilant towards their surroundings, whereas during the visual and auditory tests, more time was spent alert towards the stimulus. The horses also took significantly more steps backwards in response to the auditory test. The heart rate responses correlated between tests and reflect a non-differentiated activation of the sympathetic nervous system, while the behavioural responses were linked to the type of stimulus.
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Kruger, K., Gaillard, C., Stranzinger, G., & Rieder, S. (2005). Phylogenetic analysis and species allocation of individual equids using microsatellite data. Journal of Animal Breeding and Genetics, 122(s1), 78–86.
Abstract: Summary The taxonomic status of all equid species is not completely unravelled. This is of practical relevance for conservation initiatives of endangered, fragmented equid populations, such as the Asiatic wild asses (in particular Equus hemionus onager and E. hemionus kulan). In this study, a marker panel consisting of 31 microsatellite loci was used to assess species demarcation and phylogeny, as well as allocation of individuals (n = 120) to specific populations of origin (n = 11). Phylogenetic analysis revealed coalescence times comparable with those previously published from fossil records and mtDNA data. Using Bayesian approaches, it was possible to distinguish between the studied equids, although individual assignment levels varied. The observed results support the maintenance of separate captive conservation herds for E. hemionus onager and E. hemionus kulan. The first molecular genetic results for E. hemionus luteus remained contradictory, as they unexpectedly indicated a closer genetic relationship between E. hemionus luteus and E. kiang holderi compared with the other hemiones.
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Lamoot, I., Callebaut, J., Demeulenaere, E., Vandenberghe, C., & Hoffmann, M. (2005). Foraging behaviour of donkeys grazing in a coastal dune area in temperate climate conditions. Appl. Anim. Behav. Sci., 92(1-2), 93–112.
Abstract: A small herd of donkeys was introduced in a coastal dune reserve `Houtsaegerduinen' (ca. 80 ha) in Belgium, in order to slow down expansion of dominant grass and shrub species. The Houtsaegerduinen is a nutrient poor scrub-dominated dune system with a spatially heterogeneous vegetation pattern. Different aspects of the grazing behaviour (grazing time, bite rate, habitat use, diet composition) of the free-ranging donkeys are described and analysed. Behavioural data (of maximum six adult mares) were collected through continuous focal animal observation in three consecutive years (1998-2001). Temporal variation in grazing time, habitat use and diet composition was determined. During daylight, donkeys spent most of their time on grazing (56%). In all 3 years, grazing time was significantly shorter in summer (45% of their time), longest grazing times were achieved in spring (64%). In spring, the donkeys also achieved the highest bite rate (21.5 bites/min). The grassy habitat was preferred for foraging in all seasons, while the use of scrub and woodland was variable over time. Averaged over the four seasons, the general diet consisted for 80% of graminoids, 10% of forbs and 10% of woody plants. However, diet composition varied not only among seasons and years, but depended also on the foraged habitat type. We discuss the possible role of the donkeys in nature management.
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Fripp, D., Owen, C., Quintana-Rizzo, E., Shapiro, A., Buckstaff, K., Jankowski, K., et al. (2005). Bottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members. Anim. Cogn., 8(1), 17–26.
Abstract: Bottlenose dolphins are unusual among non-human mammals in their ability to learn new sounds. This study investigates the importance of vocal learning in the development of dolphin signature whistles and the influence of social interactions on that process. We used focal animal behavioral follows to observe six calves in Sarasota Bay, Fla., recording their social associations during their first summer, and their signature whistles during their second. The signature whistles of five calves were determined. Using dynamic time warping (DTW) of frequency contours, the calves' signature whistles were compared to the signature whistles of several sets of dolphins: their own associates, the other calves' associates, Tampa Bay dolphins, and captive dolphins. Whistles were considered similar if their DTW similarity score was greater than those of 95% of the whistle comparisons. Association was defined primarily in terms of time within 50 m of the mother/calf pair. On average, there were six dolphins with signature whistles similar to the signature whistles of each of the calves. These were significantly more likely to be Sarasota Bay resident dolphins than non-Sarasota dolphins, and (though not significantly) more likely to be dolphins that were within 50 m of the mother and calf less than 5% of the time. These results suggest that calves may model their signature whistles on the signature whistles of members of their community, possibly community members with whom they associate only rarely.
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Gomez, J. - C. (2005). Species comparative studies and cognitive development. Trends. Cognit. Sci., 9(3), 118–125.
Abstract: The comparative study of infant development and animal cognition brings to cognitive science the promise of insights into the nature and origins of cognitive skills. In this article, I review a recent wave of comparative studies conducted with similar methodologies and similar theoretical frameworks on how two core components of human cognition--object permanence and gaze following--develop in different species. These comparative findings call for an integration of current competing accounts of developmental change. They further suggest that evolution has produced developmental devices capable at the same time of preserving core adaptive components, and opening themselves up to further adaptive change, not only in interaction with the external environment, but also in interaction with other co-developing cognitive systems.
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Watson, L. H., Odendaal, H. E., Barry, T. J., & Pietersen, J. (2005). Population viability of Cape mountain zebra in Gamka Mountain Nature Reserve, South Africa: the influence of habitat and fire. Biol. Conserva., 122(2), 173–180.
Abstract: The small Cape mountain zebra population in Gamka Mountain Nature Reserve represents a third of the entire gene pool of this endangered species and is thus vital for it's conservation. Presently, management of this population is largely hands off, with the belief that it will grow to levels which will allow it to form a source for the mixing of mountain zebra stocks in the future. The growth of this population however, has been slow and we investigated the influence of habitat and fire on this growth. Firstly, we used a diffusion model to perform a population viability analysis. This analysis indicated that the population had a low probability of attaining quasi-extinction in the next 50 years (G = 0.0032). However, our findings indicated that less than 30% of the reserve was suitable for mountain zebra and that the preferred habitat would have to be burnt at unnaturally short intervals to sustain the present growth. We therefore argue that the risk of quasi-extinction to this population is greater than predicted and suggest that management options need to be implemented to reduce this risk. These options include; translocation to another protected area; acquisition of adjacent land; burning preferred habitat at unnaturally short intervals; forming a conservancy with adjacent landowners; leasing cultivated land for pasture. We suggest that only the latter two options are likely to stimulate mountain zebra population growth in the short term and that these should receive immediate attention.
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Nicol, C. J., & Badnell-Waters, A. J. (2005). Suckling behaviour in domestic foals and the development of abnormal oral behaviour. Anim. Behav., 70(1), 21–29.
Abstract: We investigated how the behaviour of domestic foals, Equus caballus, living at pasture with their dams was associated with foal gender, mare rank and the development of abnormal oral behaviour, both during the preweaning period, and over a period of up to 4 years postweaning. A population of 186 foals belonging to private owners and commercial studs was studied. The behaviour of male and female foals hardly differed, but mare rank affected patterns of foal social interaction and suckling behaviour, with foals of subordinate mares involved in more affiliative interactions. These foals also spent more time in perisuckling activities such as teat nuzzling than foals of other mares. During the study, 18 foals developed abnormal oral behaviour before weaning and 42 foals developed abnormal oral behaviour after weaning. The development of abnormal oral behaviour was associated with suckling behaviour in a variety of ways. Foals that had already developed abnormal oral behaviour at the time of the preweaning observations were involved in more suckling terminations within bouts than normal foals or foals that developed future abnormal behaviour, and pushing the udder with the muzzle was most frequent in these foals. Foals that had no current abnormal oral behaviour, but that would develop this in the future, spent more time suckling and twice as much time teat nuzzling as other foals. The results add to the growing evidence of associations between digestive function and abnormal oral behaviour in horses.
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Autio, E., & Heiskanen, M. - L. (2005). Foal behaviour in a loose housing/paddock environment during winter. Appl. Anim. Behav. Sci., 91(3-4), 277–288.
Abstract: The aim of this study was to establish some basic facts about weanling horse (Equus caballus) behaviour in a loose housing/paddock environment during winter. The behaviour of 10 foals (seven American Standardbred and three Finnish cold-blooded foals) was observed in a cold loose housing/paddock environment from December 2002 to March 2003. The time budget, circadian rhythm and effect of weather conditions on behaviour were examined. The foals were observed for a total of 23 24-h periods by video recording. The method used was instantaneous sampling (), where the locations of foals were noted at every 15 min along with the behaviour performed at that time. Temperature, humidity and wind speed were recorded three times a day. The foals spent 43.2 +/- 6.6% of the time in the sleeping hall (an insulated building with a deep-litter bed), 51.4 +/- 5.8% in the open paddock and 5.2 +/- 2.7% in the shelter (a two-sided, roofed entrance shelter in front of the sleeping hall). The time spent outdoors was greatest between the hours of 08:00 and 20:00, but the foals spent some time outdoors also at night. They spent most of the day eating hay (27.6 +/- 3.0%) (offered ad libitum), standing (25.5 +/- 2.8%) and resting (32.1 +/- 2.4%). The proportion of locomotive behaviour patterns was 5% of the observations. The foals in this study were able to perform species-specific behaviour patterns (resting, eating, being active) and to follow the natural circadian rhythm of these patterns. The behaviour of the foals did not change much as the temperature dropped from 0 to -20 [degree sign]C. The time spent in the sleeping hall did not increase greatly, nor the time spent eating, resting or lying close to each other (huddling). On the basis of their behaviour, the weanling horses did not seem to suffer from the cold environment.
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Nicol, C. J., Badnell-Waters, A. J., Bice, R., Kelland, A., Wilson, A. D., & Harris, P. A. (2005). The effects of diet and weaning method on the behaviour of young horses. Appl. Anim. Behav. Sci., 95(3-4), 205–221.
Abstract: The effects of diet on horse behaviour have not previously been quantified in detail. In this study, we examined the behaviour of 17 foals from the age of 2 to 40 weeks. Each foal received either a starch and sugar (SS) diet or a fat and fibre (FF) diet. The two diets contained similar digestible energy, crude protein and micronutrients, but differed in the fat and non-structural carbohydrate balance. The baseline behaviour of the foals was observed every 2 weeks by focal animal sampling. Additional behavioural observations were conducted when the foals were weaned by one of two methods. Approximately 2 months after weaning, the temperament and tractability of the young horses was assessed using standardised tests. Responses to a novel object, to a novel person, and during a handling test were observed and quantified. Horses grew well on both diets with no apparent effects of diet on growth rate or baseline behaviour. Immediately after weaning, horses receiving the FF diet cantered less frequently (F = 5.10; p < 0.05), for a shorter duration (F = 7.23; p < 0.05) and appeared to be more settled. Foals that were barn-weaned appeared more stressed than foals that were paddock-weaned. In the temperament tests, horses receiving the FF diet spent significantly more time investigating (F = 6.78; p < 0.05), and less time looking at (F = 7.93; p < 0.05), the novel object than horses receiving the SS diet. They also spent less time walking away from the novel person (F = 5.16; p < 0.05) and their time taken to complete the handling test was significantly lower (F = 8.72; p = 0.01). Overall, the horses that received the FF diet appeared less distressed immediately after weaning and seemed calmer and more inquisitive during a range of temperament tests.
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