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Beck, B. B. (1980). Animal tool behaviour: The use and manufacture of tools by animals. New York: Garland.
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Frank, H. (1980). Evolution of canine information processing under conditions of natural and artificial selection. Z Tierpsychol, 5.
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Harvey, P. H., Clutton-Brock, T. H., & Mace, G. M. (1980). Brain size and ecology in small mammals and primates. PNAS, 77(7), 4387–4389.
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Clutton-Brock, T. H., & Harvey, P. H. (1980). Primates, brains and ecology. J. Zool. Lond., 190(3), 309–323.
Abstract: The paper examines systematic relationships among primates between brain size (relative to body size) and differences in ecology and social system. Marked differences in relative brain size exist between families. These are correlated with inter-family differences in body size and home range size. Variation in comparative brain size within families is related to diet (folivores have comparatively smaller brains than frugivores), home range size and possibly also to breeding system. The adaptive significance of these relationships is discussed.
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Asa, C. S., Goldfoot, D. A., Garcia, M. C., & Ginther, O. J. (1980). Sexual behavior in ovariectomized and seasonally anovulatory pony mares (Equus caballus). Horm Behav, 14(1), 46–54.
Abstract: Ten ovariectomized (OVEX) and ten intact, but seasonally anovulatory (ANOV), pony mares were observed for sexual activity with five stallions, using a “harem group” social testing paradigm (two OVEX and two ANOV mares plus one stallion per group) for 15 consecutive daily tests lasting 20 min each. All mares in both conditions showed proceptive behavior in at least one test, all mares but one were mounted, and 14 of 20 mares received ejaculations. No statistical differences were found between the two conditions for any measure of proceptivity, copulatory activity, or days in estrus. The quality of estrus was judged to be equivalent to that displayed by periovulatory mares during their initial and terminal days of estrus, but less intense than that seen near ovulation. Mares in both groups were in estrus during approximately 60-70% of the tests and only 3 of the 20 mares were sexually refractory for more than five consecutive tests. Thus, the typical 2-week phase of sexual refractoriness seen in intact diestrous mares was absent in OVEX and ANOV mares, suggesting that the ovary plays a major role in actively suppressing estrous responses during the luteal phase of the cycle.
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Asa, C. S., Goldfoot, D. A., Garcia, M. C., & Ginther, O. J. (1980). Dexamethasone suppression of sexual behavior in the ovariectomized mare. Horm Behav, 14(1), 55–64.
Abstract: The influence of steroids of adrenal cortical origin on estrous behavior in the ovariectomized mare was evaluated by adrenal suppression via dexamethasone (DEX) administration in two experiments. In Experiment I, 12 mares (six DEX, six control) were tested for sexual behavior in harem groups (two DEX and two control mares plus one stallion per group) for 9 consecutive days. In Experiment II, estradiol (E2) was given to a group of DEX-treated mares as an additional control. Twelve mares (four DEX, four DEX + E2, and four control) were tested in harem groups (one DEX, one DEX + E2, and one control mare plus one stallion per group) for 10 days. All DEX mares showed a clear suppression of sexual response compared to control or DEX + E2 mares, indicating that the estrous behavior seen in ovariectomized mares may be due to steroids from the adrenal cortex. The control and DEX + E2 mares were similar in all measures of proceptivity. Despite being more receptive, as indicated by fewer negative responses, the DEX + E2 mares received fewer intromissions and ejaculations than did the control animals. The ability of estradiol to induce estrous behavior in the dexamethasone-suppressed mare notwithstanding, other adrenal steroids, e.g., androgens, may be involved in estrous behavior in the untreated, ovariectomized mare.
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Appleby, M. C. (1980). Social Rank and Food Access in Red Deer Stags. Behaviour, 74, 294–309.
Abstract: The behaviour of a free-living group of male red deer (Cervus elaphus L.) on the Isle of Rhum, Scotland, was studied throughout the year to investigate the relations between social dominance and food access. The study is based on the collection of agonistic interactions between members of the study group outside the rutting season. Analysis of these confirmed that dyadic dominance relationships summate to a very clear agonistic hierarchy, while seasonal changes in frequency and type of interactions suggested that rank in the hierarchy may affect access to food through direct feeding interference. This would constitute a selective advantage of the acquisition of high rank. A behaviour pattern in which a stag displaces a subordinate and takes over his feeding-site is proposed as a mechanism of direct feeding interference. It occurs throughout the year, but with a frequency closely related to changes in food availability and quality. The proportion of such interactions that an individual wins is related to his rank, so advantages gained from this behaviour would primarily benefit high-ranking stags. These are likely to consist of improved body condition and winter survival. The importance of high rank in obtaining access to limited food was supported by the results of a simple experiment providing a small area of fertilized grass. Most of the grazing in the area was due to the highest-ranking stag present at any time.
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Haag, E. L., Rudman, R., & Houpt, K. A. (1980). Avoidance, maze learning and social dominance in ponies. J. Anim. Sci., 50, 329–335.
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Parry, B. W., Gay, C. C., & McCarthy, M. A. (1980). Influence of head height on arterial blood pressure in standing horses. American Journal of Veterinary Research, 41(10), 1626–1631.
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Brügger, A. (1980). Gesunde Körperhaltung im Alltag. Zürich: Dr. A. Brügger.
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