No abstract

Prior to the present study, no systematic field data were available on the behaviour and ecology of Erythrocebus patas. This monkey, widely distributed over the grass and woodland savannah regions of West and East Africa, appears to be unique in some of its physical and social adaptations to a terrestrial mode of life. In three main study periods, 640 hours of observation were carried out on groups in the Murchison Falls National Park. Small samples of data on baboon and vervet groups in the same area were obtained. Numerical sizes of patas groups ranged from 9 to 31, mean 15. In no group was there more than one full‐grown male. Groups were followed for many successive day‐ranges, distances travelled varying from group to group, season to season, with a maximum of about 12,000 m and a minimum of 500 m. Home range size of one group was 5200 hectares. Groups tended to use a different area of the home range each night, and individuals dispersed far apart in taking up night resting positions in trees. The day activity pattern comprised two main feeding periods, with a rest period of one to three hours in the hottest time. Drinking at water holes or other sources was infrequent. Infants less than three months old occurred only up to June, and were commonly seen in March and April. Infants aged 3 to 12 months, and juveniles, engage frequently in long, active bouts of play‐chasing, wrestling, and bush‐bouncing–almost all play is on the ground. Grooming amongst them is common, its social pattern being similar to baboons. Submissive gestures are very rarely seen, baboon‐like presenting and being mounted not occurring. Threat‐attack is mainly by adult females, very rarely by the adult male. Vocalizations audible at about 100 m occur very infrequently (about two to four a day, compared with 25 to 50 for baboon groups). The adult male patas plays the part, for the group, of watchdog. Whenever the group is disturbed, or approaches new areas, he may reconnoitre from a high point several hundred metres away from the group. When disturbed by the observer, he has a noisy, bouncing display on bushes and trees, and probably a form of diversionary display by running away from his group and from the observer. In the group, he is spatially peripheral, except when day resting, mating and grooming, and the adult females habitually initiate directions and times of group movement. Their function is essentially that of looking after themselves, their infants, and the juveniles, while that of the adult male is very strikingly that of watching for predators or other patas groups or baboons, etc. Isolated adult males and one all‐male party of four have been observed. Spacing between groups is such that inter‐group encounters are exceedingly rare (two occurrences only). Reaction consisted of chasing by the larger group, rapid avoidance by the smaller. A contralto bark is uttered repeatedly, in short series, by the adult male of a group only, it seems, on encounters with extra‐group patas. The patas adaptations of swift locomotion, silence, con...

No abstract

Few systematic field observations of the behaviour and ecology of the Chacma baboon, Papio ursinus, have been reported since Zuckerman (1932). The present study has set out to obtain reliable evidence on all aspects of the behaviour of natural‐living groups of these animals in two regions of their extensive distribution in Southern Africa—the arid thornveld of South‐west Africa and the temperate area of the Cape Peninsula. Field work was carried out in two parts: (1) regular observations of groups of baboons in the Cape of Good Hope Nature Reserve for a period of one year; (2) intensive observation (200 hours) of a single group in the Reserve, as well as extensive surveying of groups in the mountainous regions of South‐west Africa. The present paper gives numerical data on thirty‐one groups, analysis of group constitution, day‐ranging distances and sizes of occupied areas, times of leaving and returning to sleeping‐cliffs, and other data on routine activities. Particular attention has been paid to schedules of food and the description of feeding‐techniques, and field observation has been supplemented by some simple experimental tests on the eating of scorpions and other creatures. Close range observations were made of baboons eating shell‐fish, and some evidence is presented on the acquisition of feeding habits through observational‐learning (imitation).

No abstract

In natural groups of mammals, there is a variety of social influences which seem to inhibit or facilitate the expression of instinctive behaviour-patterns, and indeed which contribute importantly to the fr,rm the repertoire of behaviour characteristic of the species takes. Such influences include what goes under the terms 'social facilitation' and 'imitation', as well as other terms such as 'identification' which imply a special affectional relationship.From an analysis of the evidence about these influences on monkeys and apes, it is clear that negative experimental findings have often been due to the limitations of the experimental procedures, and that some of the positive findings are difficult to interpret or aasess for validity because of deficient method. By and large, there is convincing observiitional evidence, chiefly from informal developmental and from field studies, that young monkeys and apes acquire certain basic feeding and avoidance habits chiefly by applying their exploratory tendencies to places and objects indicated in the behaviour of their mothers or others of the group.Although, in terms of learning operations, it is unlikely that much more than stimulusenhancement or place discriminations is usually involved, a 'new' motor sequence almost never being in evidence, there is no doubt that the affectional situation of the participants is crucial m to whether a 'demonstrator' is attended to, closely approached, and 'imitated', or not. The nature of the affectional variables and their influence upon learning require extensive experimental study and analysis, and a comparison with related forms of early learning, such aa imprinting, can then be made. 202K. R. L. HALL heavily emphasized by Darwin (1874), Tarde (1904)) McDougall(1908), and others. But the comparative assessment of the importance of such tendencies in non-human animals has been somewhat neglected. Axiomatically, it seems likely that the origins, in individual mammalian life experience, of the conventionalizing tendency come early in ontogeny as the infant animal learns to achieve a certain independence of its mother, having of necessity conformed to the mother's control during the period of weaning, and having, inevitably in the natural group situation, observed almost exclusively the behaviour of those closest to the mother. Then, as the young animal matures, its spontaneous and characteristic playfulness leads it to learn certain social habits in the rough-and-tumble of the play subgroup, but its physical survival habits, such as those connected with feeding and drinking and avoidance of the noxious, are probably early established in the daily process of observing the mother and her immediate associates.All this sounds obvious, but so suspiciously obvious that one finds the real nature of the conforming process in the higher animals has by no means been elucidated experimentally or in the course of naturalistic studies of wild groups. Only in the most general terms have the complex processes involved been described, and, within the...

24Tactical deception has been widely reported in primates on a functional basis, but details 25 of behavioral mechanisms are usually unspecified. We tested a pair of chimpanzees (Pan 26 troglodytes) in the informed forager paradigm, in which the subordinate saw the location 27 of hidden food and the dominant did not. We employed cross-correlations to examine 28 temporal contingencies between chimpanzees' behavior: specifically how the direction of 29 the subordinate's gaze and movement functioned to manipulate the dominant's searching 30 behavior through two tactics, withholding and misleading information. In Experiment 1, 31 not only did the informed subordinate tend to stop walking towards a single high value 32 food, but she also refrained from gazing towards it, thus withholding potentially revealing 33 cues from her searching competitor. In a second experiment, in which a moderate value 34 food was hidden in addition to the high value food, whenever the subordinate alternated 35 her gaze between the dominant and the moderate value food, she often paused walking 36 for 5 seconds; this frequently recruited the dominant to the inferior food, functioning as a 37 'decoy'. The subordinate flexibly concealed and revealed gaze towards a goal, which 38 suggests that not only can chimpanzees use visual cues to make predictions about 39 behavior, but also that chimpanzees may understand that other individuals can exploit 40 their gaze direction. These results substantiate descriptive reports of how chimpanzees 41 use gaze to manipulate others, and to our knowledge are the first quantitative data to 42 identify behavioral mechanisms of tactical deception. 43 44

Metabolism of chemicals from the diet, exposures to xenobiotics, the microbiome, and lifestyle factors (e.g., smoking, alcohol intake) produce electrophiles that react with nucleophilic sites in circulating proteins, notably Cys34 of human serum albumin (HSA). To discover potential risk factors resulting from in utero exposures, we are investigating HSA-Cys34 adducts in archived