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Jensen, G. D., Gordon, B. N., & Wolfheim, J. (1975). Nursing behavior in infant monkeys: a sequence analysis. Behaviour, 55(1-2), 115–127.
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Stober, M., & Geiger, J. F. (1975). [Lamenting “moaning” in domestic cattle]. Dtsch Tierarztl Wochenschr, 82(1), 10–13.
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Zentall, T. R., & Hogan, D. E. (1975). Key pecking in pigeons produced by pairing keylight with inaccessible grain. J Exp Anal Behav, 23(2), 199–206.
Abstract: In Experiment I, keylight was paired with inaccessible grain delivery (under two conditions of keylight intensity) to determine if autoshaping would occur in the absence of primary reinforcement. In Experiment II, the procedure was repeated with accessible grain, for comparison. In Experiment III, the procedures were repeated with explicitly unpaired presentations of keylight and either inaccessible or accessible grain. The results indicated that key pecking occurred as quickly in the presence of keylight pairings with inaccessible grain as with accessible grain, though (except for one bird) key pecking was not maintained with inaccessible grain. Furthermore, compared to the dim keylight, the bright keylight greatly suppressed key pecking when paired with inaccessible grain, and reduced the rate of key pecking when paired with accessible grain. Little key pecking occurred in groups exposed to explicitly unpaired presentations of keylight (whether bright or dim) and grain (whether accessible or inaccessible). When the birds in Experiment III were retested with explicitly paired presentations of keylight and grain, little key pecking was observed, suggesting suppressive effects of prior explicitly unpaired presentations. It is suggested that the effects of key-brightness manipulation were produced by the association of grain with cues other than the response key, or by distraction produced by partial illumination of the grain hopper.
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Ayeni, J. S. O. (1975). Utilization of waterholes in Tsavo National Park (East). African Journal of Ecology, 13(3-4), 305–323.
Abstract: Summary Utilization of waterholes by wildlife was studied between April, 1973 and July, 1974 in Tsavo National Park (East), south of the Voi river. Seasonality was an important factor which influenced the various aspects of waterhole utilization. The numbers of the herbivores utilizing the waterholes increased during the dry season but fell during the rains. Some ungulates also moved near to the artificial waterholes in the dry season but moved away from them during the rains when they drank from natural water-holes formed in clay pans filled with rain water. A basic pattern of waterhole utilization dominated by small (adult-size) species during day-time 06.00–18.00 hours and larger species at night 18.00–06.00 hours is described. The separation in times of arrival and deparature peaks of waterhole utilization, and average coincidence of percentages of paired species populations are used to show that big-game attained a measure of time-spaced ecological separation at the waterholes. The water relations of some day-time and night-time drinkers are discussed. From the baseline study the management implications of the development of additional waterholes in the park are discussed.
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Douglas Rh, G. O. (1975). Development of the equine fetus and placenta. J Reprod Fert (Suppl), 23, 495–498.
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Imesh Gd, S. G. (1975). Gross and microscopic observations of ovarian abnormalities from five Burchell's zebra. Onderstepoort J vet Res, 42, 109–116.
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Klingel, H. (1975). Social organization and reproduction in equids. J Reprod Fertil Suppl, (23), 7–11.
Abstract: There are two distinct types of social organization and, accordingly, two types of mating systems in equids. In the horse, Plains zebra and Mountain zebra, the adults live in non-territorial and cohesive one-male groups and in stallion groups. The family stallions have exclusive mating rights which are respected by all others. In Grevy's zebra and in the African and Asiatic wild asses, the stallions are permanently territorial and have exclusive mating rights within their territories. Ecological and evolutionary aspects are discussed.
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Welsh Da,. (1975). Population, behavioural, and grazing ecology of the Sable Island, Nova Scotia. Ph.D. thesis, Dalhousie University, Halifax.
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Syme, G. J., & Syme, L. A. (1975). The concept of spatial leadership in farm animals: An experiment with sheep. Anim. Behav., 23(Part 4), 921–925.
Abstract: The concept of spatial leadership as applied to farm animals is discussed with particular emphasis on methodological problems. Using three experimental procedures forced spatial leadership orders were measured in a group of Romney ewes. Comparisons between orders showed the effects of both the different experimental tasks and the social context on leadership structure. Both these variables were found to affect the orders obtained. The results are interpreted in terms of the utility of the concept of spatial leadership in domestic animals and the necessity for more systematic procedural investigations in this area.
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Wagner, G. (1975). [Flight leadership in flocks of homing pigeons]. Z. Tierpsychol., (39), 61–74.
Abstract: Groups of 3-5 homing pigeons individually recognizable by different colours of their plumage were followed by helicopter on their way home. In most cases the animals flew together as a group with frequently changing leadership. Flight formations in terms of leadership were noted every minute. It was examined statistically whether the flight order varies at random or whether there are leading and led birds. In 6 out of 7 experiments with groups of 4-5 pigeons flight order was far from random, one or two pigeons proving to be leaders. In only one experiment leadership did not differ from a random distribution. No correlation could be found between the tendency to lead within a group and homing performance of the single pigeon when released individually.
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