T.E. Rowell

The concept of social dominance.

Dominance has been assumed to be a quality of overwhelming social importance but satisfactory definitions and measures have not been devised. As an indication of predictability of outcome of interaction between animals, it can be explained in terms of ordinary learning processes previous to and during a specific relationship. Agonistic interactions are usually determined and often initiated by the subordinates behavior, and subordinate behavior is correlated with physiological changes, so that a subordination hierarchy is probably a more useful concept than a dominance hierarchy. Hierarchies develop in stressful conditions, especially in captivity where animals with overresponsive adrenal cortices are at a selective disadvantage. In wild groups hierarchies are tenuous or absent and stress-responsive members are probably advantageous to a group. Group defense and leadership roles are not correlated with rank, but policing is characteristic of high-ranking animals in species where it occurs. There is no evidence that formation of a hierarchy reduces aggression—hierarchies are actually associated with high rates of aggression in primate groups. There is no conclusive evidence that high ranking males have greater overall reproductive success, and an alternative hypothesis that adult males are sexually active for a relatively short stage of their lives fits existing data equally well.

A quantitative comparison of the behaviour of a wild and a caged baboon group

Abstract 1. (1) A wild and a caged baboon population were compared on the basis of roughly 300 hr of observation on each population. The effect of different population compositions is discussed. 2. (2) Comparison was of the number and type of interactions seen between adult males, adult females and weaned juveniles and of the incidence of twenty common behaviour patterns in these interactions. 3. (3) Interactions were nearly four times more frequent in the cage than in the wild. 4. (4) Approach-retreat (as opposed to friendly) interactions were more common in the cage. This increase was not even throughout all eight classes of interactions for which comparison was available, but was especially marked in female-female interactions. 5. (5) The structure of approach-retreat interactions in the two populations did not differ much within each interaction class. Most differences occurred in those patterns which are also included in play behaviour and were shown elsewhere to be little correlated with rank order in the caged group. 6. (6) Friendly behaviour showed more differences, many of which were consistent with a higher level of stress in the caged group. 7. (7) Wild adult males had no detectable hierarchy and frequently moved between troops. Their approach-retreat behaviour was similar to that of wild adult females amongst themselves; their friendly behaviour differed in a way that suggested a higher degree of tension than between females. The role of the males in the group in forming a highly co-operative policing system is described. 8. (8) Results are discussed in terms of the relation between hierarchy formation and environmental stress.

Reconciliation following aggression in patas monkeys, Erythrocebus patas

Abstract Following intra-group aggression, obvious conciliatory displays are absent from the behavioural repertoire of patas monkeys, Erythrocebus patas, while many other Old World primate species show special reconciliation gestures. When 10-min focal-animal samples that began after spontaneous aggression were compared with matched-control samples, captive adult female patas followed up on aggressive interactions, interacting sooner and more often with former opponents during post-conflict observations than during matched-control observations. Almost one-third of post-conflict observations included affiliative behaviour between former opponents, which is termed reconciliation. Matrilineally related opponents were more likely to reconcile with one another than were unrelated animals. No effect of the dominance hierarchy on tendency to reconcile was found. Thus, patas monkeys showed general patterns in post-conflict behaviour that were similar to those seen in other primates previously investigated.

Behaviour and Female Reproductive Cycles in a Captive Group of Mangabeys

The behaviour of a captive group of mangabeys is described in terms of the frequency with which different members of the group showed certain behaviour patterns. For some patterns, these frequencies r

Maternal behaviour in non-maternal golden hamsters (Mesocricetus auratus)

Abstract Non-lactating Golden hamsters were offered young pups, and their reaction towards them observed. Adults and juveniles of both sexes were tested. All groups would show maternal behaviour, in particular, “retrieving” of young. Solitary adult females would treat maternally only those pups they found actually in their nest. Juveniles began to retrieve younger pups as soon as they were strong enough, and when living in groups without their mother continued to retrieve or tolerate pups after sexual maturity. Living with their mother they began to attack pups at about five weeks, before the females were mature. When group-living females were isolated, they also began to be aggressive to pups. The results are compared with published data on rats and mice.

Comparison of seed dispersal by guenons in Kenya and capuchins in Panama

We should like to draw attention to differences we have observed between the ways some New and Old World forest monkeys handle fruits and the seeds they contain. We believe that these differences imply different roles for monkeys in their forest ecosystems, and may represent different sets of selection pressures on fruit-bearing plants in African and South American forests. Monkeys disperse seeds in both Africa and Latin America. Jackson & Gartlan (1965) showed that vervet monkeys carried seeds to termite mounds in grassland adjacent to the forest in Uganda, and so caused the spread of forest into grassland. Lieberman et al. (1979) found that baboons disperse seeds in dry forest in Ghana. Gautier-Hion et al. (1985) describe about 40 species of plants as dispersed by Cercopithecine monkeys in a Gabonese rain forest. Monkeys known to disperse seeds in New World rain forests include howlers (Chapman 1989, Estrada & Coates-Estrada 1986, Hladik & Hladik 1969, Howe 1980), tamarins (Hladik & Hladik 1969, Garber 1986), spider monkeys (Chapman 1989, Hladik & Hladik 1969, Howe 1980), and capuclhins (Chapman 1989, Hladik & Hladik 1969, Janson et al. 1986). Monkeys eat a wide range of fruits of different shapes and sizes, and it is unlikely that they could be effective agents of dispersal for all of the species that they consume. The quality of dispersal offered to a particular fruit species by a particular animal depends onthe animals behaviour, physiology, and morphology: food handling, processing, and gut passage time affect the viability of a seed after the animal is finislhed with it and the size of the clump in which it is deposited; ranging and movement patterns affect where a seed is likely to be deposited with respect to microhabitat conditions and the prevalence of natural enemies, and therefore the fate of the seeds and seedlings (Howe 1989, Janzen 1983, Levey 1987, Lieberman & Lieberman 1986). In this note we consider mainly the first phase of seed dispersal: the removal of seeds from the parent tree and subsequent deposition. Variation in patterns of remzoval and

Group fission in blue monkeys of the Kakamega forest, Kenya

A group of 46 blue monkeys split into two daughter groups which divided the original home range into two new territories. The smaller group obtained a smaller and less favored area. The fission appear

Variation in Age at Puberty in Monkeys

5 female and 3 male patas monkeys and 6 female and 3 male talapoin monkeys matured in a captive breeding colony. Age at puberty is given, and some variation discussed. The talapoin, a very small monkey, becomes adult at 4 1/2 years for females, 1 or 2 years later for males. The patas, a rather large monkey, becomes adult at 2 1/2 years, for females, and 1 or 2 years later for males. Both these ages for puberty differ from data for the rhesus monkey which has been accepted as generalizable to all Old World monkeys. Possible causes of differences between species in average age at puberty are discussed, including nutrition, environmental inconstancy, and relative size of infant and mother. It is suggested that age at first conception, a biologically more relevant index than menarche, should be considered as a potentially important adaptive variable when describing primate species.

Grooming by adult baboons in relation to reproductive cycles

Abstract In the late follicular phase of their menstrual cycle, group-living female baboons were groomed more frequently by males, and they themselves groomed males more and other females less. Females were groomed more by other females when lactating, rather less when pregnant and when deflating (early luteal phase), than average. The increase in male-grooming by swollen females differs from previous findings, it is suggested because of different observation conditions. The reproductive state of the female does not affect the frequency with which she grooms, but only the frequency with which she is groomed.

Communication among captive talapoin monkeys (Miopithecus talapoin).

The behavioral repertoire of 18 captive, groupliving, talapoin monkeys is described. Postures, body gestures, and noises provide their most important signals. Facial gestures are used rarely. Ganging-