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Goodwin, D. (2007). Equine learning behaviour: What we know, what we don't and future research priorities. Behav. Process., 76, 17–19.
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Linklater, W. L. (2007). Equine learning in a wider context--Opportunities for integrative pluralism. Behav. Process., 76, 53–56.
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Horner, V., & Whiten, A. (2007). Learning from others' mistakes limits on understanding a trap-tube task by young chimpanzees (Pan troglodytes) and children (Homo sapiens). J Comp Psychol, 121(1), 12–21.
Abstract: A trap-tube task was used to determine whether chimpanzees (Pan troglodytes) and children (Homo sapiens) who observed a model's errors and successes could master the task in fewer trials than those who saw only successes. Two- to 7-year-old chimpanzees and 3- to 4-year-old children did not benefit from observing errors and found the task difficult. Two of the 6 chimpanzees developed a successful anticipatory strategy but showed no evidence of representing the core causal relations involved in trapping. Three- to 4-year-old children showed a similar limitation and tended to copy the actions of the demonstrator, irrespective of their causal relevance. Five- to 6-year-old children were able to master the task but did not appear to be influenced by social learning or benefit from observing errors.
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Murphy, J., & Arkins, S. (2007). Synthesizing what we know of equine learning behaviour. Behav. Process., 76, 57–60.
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Bohnet, W. (2007). Expressive behaviour to assess the emotional states in horses. Dtsch Tierarztl Wochenschr, 114(3), 91–97.
Abstract: The emotional states such as feelings and emotions are not easy to assess by objective methods in animals as well as in humans. Beside measuring physiological variables an aid to assess the emotional states is the analysis of expressive behaviour of an individual respecting the relating context. Especially developed in mammals, which live in obligatory social i.e. in stable permanent social communities, are facial expression and gesture. Also horses display a differentiated expressive behaviour, which can be observed and analysed by humans. Moreover it could be demonstrated, that in situations of stress the display shown by horses (gesture, facial expression, posture) correlate with corresponding physiological reactions. Thus the expressive behaviour is suitable to assess the emotional states of horses depending on the situation.
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Dugatkin LA. (2007). Developmental environment, cultural transmission, and mate choice copying. Naturwissenschaften, 94(8), 651–656.
Abstract: Using female mate choice copying as a rudimentary form of cultural transmission, this study provides evidence that social environment during development has a significant effect on the tendency to use culturally acquired information. Groups of newborn guppies (Poecilia reticulata) were raised for 35 days in 1 of 5 “developmental environments”. Groups of 15 newborns were raised in pools with no adults (treatment 1), both adult male and female guppies (treatments 2 and 3), only adult females (treatment 4) or only adult males (treatment 5). Mature females raised in treatments 1 and 2, but not treatments 3, 4, and 5, copied the mate choice of others. Treatments 1 and 2 correspond to social structures that guppies experience during their development in the wild. Newborn guppies swim together in shoals (analogous to treatment 1). As they mature, juveniles join schools of adult males and females (analogous to treatments 2). At no time during the normal developmental process are juveniles found with males, but only unreceptive females (as was the case for long periods in treatment 3) or in the presence of adults of only one sex (analogous to treatments 4 and 5). As such, normal developmental environments prime guppies for cultural transmission, while unnatural environments fail to do so.
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Sharon, L., & Crowell-Davis, S. L. (2007). Sexual behavior of mares. Horm Behav, 52(1), 12–17.
Abstract: The mare is seasonally polyestrus, having an anovulatory period during the short light days of late fall and early winter, and beginning to ovulate as the days become longer during the winter. The complete estrus cycle is typically about 3 weeks, with 5 to 7 days of estrus and approximately 2 weeks of diestrus. When a mare lives within the natural social structure of the horse, i.e. a family band with several adult mares and one or more stallions, estrus is characterized by repeatedly approaching the stallion, frequent urination, deviating the tail away from the perineum, and standing still with the hind limbs spread apart. Diestrus is characterized by avoidance of an approaching stallion, and aggression toward the stallion, such as squealing, striking, and kicking, if he persists in attempting to court the diestrus mare. However, mares and stallions with long-term social relationships will often rest together, graze together and groom each other, all without sexual interactions. Hormonally, estrous behavior in the mare is initiated by estradiol that is secreted by the follicle, while estrous behavior is suppressed by progesterone, secreted by the corpus luteum. Mares are unusual among the ungulates in that they periodically exhibit estrous behavior during the anovulatory period. This is probably due to the release of estrogenic steroids secreted by the adrenal cortex. The display of sexual behavior by the mare throughout the year is thought to facilitate maintenance of the horse's social structure, in which the male remains with a group of females year round, in contrast with most ungulates in which the females and males only come together during the mating season.
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King, S. R. B., & Gurnell, J. (2007). Scent-marking behaviour by stallions: an assessment of function in a reintroduced population of Przewalski horses (Equus ferus przewalskii). J Zool, 272(1), 30–36.
Abstract: Abstract Scent marking is a common form of intraspecific communication in mammal species, and using faeces or urine is a cost-effective way of signalling competitive ability and resource holding power. Marking is ritually performed by male equids, and here we assess the function of male scent-marking behaviour in a recently introduced population of Przewalski horses Equus ferus przewalskii in Mongolia. Two forms of scent marking were observed: defecation on stud piles formed from repeated dunging in the same place, and overmarking of faeces and urine of mares. Stud piles were marked with dung by the harem holder and sniffed before and after dung was deposited. They were not found specifically at the periphery of harem ranges but occurred for the most part along routes used by the horses, and were more common in the core parts of harem ranges or where harem ranges overlapped. Thus, rather than being used to defend range boundaries, stud piles were placed predominantly where they would be encountered by male intruders. Mare excreta were covered with urine by the stallion, but were only sniffed before they were marked, not after. These marks appear to advertise to the mare and other, intruding stallions that the harem holder was the mare's consort and that the interloper should not risk trying to steal the mare or sneak a mating. Thus, the two forms of marking by harem holders appear to combine as first and second lines of defence of paternity rights in male intrasexual competition.
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Kulikova, E. E., Isaeva, A. S., Rotkina, A. S., Manykin, A. A., & Letarov, A. V. (2007). Diversity and dynamics of bacteriophages in horse feces. Microbiology, 76(2), 271–278.
Abstract: The complex cellulolytic microbial community of the horse intestines is a convenient model for studying the ecology of bacteriophages in natural habitats. Unlike the rumen of the ruminants, this community of the equine large intestine is not subjected to digestion. The inner conditions of the horse gut are much more stable in comparison to other mammals, due to the fact that the horse diet remains almost unchanged and the intervals between food consumption and defecation are much shorter than the whole digestive cycle. The results of preliminary analysis of the structure and dynamics of the viral community of horse feces, which combines direct and culture methods, are presented. In horse fecal samples, we detected more than 60 morphologically distinct phage types, the majority of which were present as a single phage particle. This indicates that the community includes no less than several hundreds of phage types. Some phage types dominated and constituted 5-11% of the total particle count each. The most numerous phage type had an unusual morphology: the tails of its members were extremely long (about 700 nm), flexible, and irretractable, while their heads were 100 nm in diameter. Several other phage types with similar but not identical properties were detected. The total coliphage plaque count of the samples taken from three animals revealed significant fluctuations in the phage titers. During the observation time, the maximum titer ranged within four orders of magnitude (10(3)-10(7) plaque forming units (PFU)/g); the minimum titer ranged within two orders of magnitude. The samples contained two to five morphologically distinct and potentially competitive coliphage types, specific to a single Escherichia coli strain.
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Penn, D. C., & Povinelli, D. J. (2007). Causal Cognition in Human and Nonhuman Animals: A Comparative, Critical Review. Annual Review of Psychology, 58(1), 97–118.
Abstract: In this article, we review some of the most provocative experimental results to have emerged from comparative labs in the past few years, starting with research focusing on contingency learning and finishing with experiments exploring nonhuman animals' understanding of causal-logical relations. Although the theoretical explanation for these results is often inchoate, a clear pattern nevertheless emerges. The comparative evidence does not fit comfortably into either the traditional associationist or inferential alternatives that have dominated comparative debate for many decades now. Indeed, the similarities and differences between human and nonhuman causal cognition seem to be much more multifarious than these dichotomous alternatives allow.
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