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Schilder Mbh, B. P. (1987). Ethological investigations on a herd of Plains Zebra in a safari park: Time – budgets, reproduction and food competition. App Anim Behav Sci, 18, 45–56.
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Scheunert, A. T., A. (1987). Lehrbuch der Veterinär-Physiologie. Berlin: Parey.
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Satorov, S. S., & Orzuev, M. I. (1987). [Frequency of the isolation of staphylococci from domestic animals and strain identification]. Zh Mikrobiol Epidemiol Immunobiol, (12), 37–39.
Abstract: Staphylococci occur in donkeys more frequently than in other animals, and only from donkeys coagulase-negative staphylococci, characteristic of humans (S. hominis, S. capitis, S. cohnii), were isolated. Least frequently staphylococcal carrier state was registered in cats; in these animals only coagulase-negative strains were found to occur. From 30 donkeys coagulase-positive staphylococci belonging to 47 S. aureus strains were isolated. These strains differed from known ecological variants in their biological properties, thus suggesting the existence of S. aureus ecovar specific for donkeys. These strains did not coagulate human, bovine and ovine plasma, but coagulated rabbit plasma in 100% of cases and donkey plasma only in 53% of cases; at the same time they relatively often produced delta hemolysin, rarely phosphatase and hyaluronidase and never fibrinolysin. These strains were typed by KPC phages, mainly 116 and 117.
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Rutberg, A. T. (1987). Horse Fly Harassment and the Social Behavior of Feral Ponies. Ethology, 75(2), 145–154.
Abstract: Abstract Horse flies (Tabanidae) on and around feral ponies in harem groups were counted at Assateague Island National Seashore, Maryland, U.S.A., between June and August 1985. Harem stallions attracted the most flies; adult mares showed intermediate fly numbers, while few flies landed on foals under any circumstances. The use of thermal and chemical cues by flies selecting a host may have helped create this disparity. When flies were abundant, ponies reduced spacing within the group. Ponies in larger groups suffered from fewer flies than ponies in smaller groups. There was, however, no evidence that ponies merged into larger groups in response to fly harassment, suggesting that biting flies play little role in structuring pony social organization.
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Rumbaugh, D. M., Savage-Rumbaugh, S., & Hegel, M. T. (1987). Summation in the chimpanzee (Pan troglodytes). J Exp Psychol Anim Behav Process, 13(2), 107–115.
Abstract: In this research, we asked whether 2 chimpanzee (Pan troglodytes) subjects could reliably sum across pairs of quantities to select the greater total. Subjects were allowed to choose between two trays of chocolates. Each tray contained two food wells. To select the tray containing the greater number of chocolates, it was necessary to sum the contents of the food wells on each tray. In experiments where food wells contained from zero to four chocolates, the chimpanzees chose the greater value of the summed wells on more than 90% of the trials. In the final experiment, the maximum number of chocolates assigned to a food well was increased to five. Choice of the tray containing the greater sum still remained above 90%. In all experiments, subjects reliably chose the greater sum, even though on many trials a food well on the “incorrect” tray held more chocolates than either single well on the “correct” tray. It was concluded that without any known ability to count, these chimpanzees used some process of summation to combine spatially separated quantities. Speculation regarding the basis for summation includes consideration of perceptual fusion of pairs of quantities and subitization.
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Rapaport, L., & King, N. E. (1987). The behavioral research program at the Washington Park Zoo. Appl. Anim. Behav. Sci., 18(1), 57–66.
Abstract: For the past decade, the Washington Park Zoo, Portland, Oregon, has had an active behavioral research program. The research department is both a zoo-supported research facility for visiting researchers and staff, and an educational facility that teaches practical behavioral research methods to undergraduates. The research education program utilizes students from any of a dozen local colleges and universities. Students receive academic credit for their participation. Active keeper-participation plays a major role in many research projects. Not only does keeper-cooperation facilitate research, but their knowledge of the individual animals often proves invaluable. In addition to involvement in student projects, keepers have also conducted their own research projects.
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Pusey, A. E. (1987). Sex-biased dispersal and inbreeding avoidance in birds and mammals. Trends. Ecol. Evol, 2(10), 295–299.
Abstract: Sex differences in dispersal distance are widespread in birds and mammals, but the predominantly dispersing sex differs consistently between the classes. There has been persistent debate over the relative importance of two factors -- intrasexual competition and inbreeding avoidance -- in producing sex-biased dispersal, and over the sources of the difference in dispersal patterns between the two classes. Recent studies cast new light on these questions.
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Povinelli DJ. (1987). Monkeys, apes, mirrors and minds: the evolution of self-awareness in primates. J. Hum. Evol., 2, 493.
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Penzhorn Bl, L. P. (1987). Comparisons of reproductive parameters of two Cape mountain zebra populations. J Reprod Fert Suppl, 35, 661–663.
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Penzhorn Bl, G. R. (1987). Incisor wear in free – ranging Cape mountain zebras. S Afr J Wildl Res, 17, 99–102.
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