Evolution.

Society for Experimental Biology

Date:: 1953

Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Evolution. Source: Wellcome Collection.

458/484 (page 426)

428 SOCIAL BEHAVIOUR AND PRIMATE EVOLUTION The situation is so intense that the males holding territory do not leave them over a period of 54-57 days (Scheffer & Kenyon), during which they digest the 200 lb. of fat which constitutes roughly one-third of their weight at the start of the mating season. Intense fighting occurs during the maintenance of the harems, and the animals are often severely injured or killed. The males without territories and harems are able to move down to the sea from the rear of the shore by means of channels between the territories. The presence of other animals in these neutral zones does not provoke a challenge from the neighbouring males, and, indeed, Mulvey used these channels to get close to the animals and observe their behaviour. If, however, an animal transgresses the boundaries of one of these territories he is immediately challenged by the overlord male, and the only alter¬ natives are to flee, escape into the neutral zones or stay and fight. Such challenges between hitherto subordinate animals and overlords have been observed and either may be the victor. Thus we have a situation in the seal in which the provocation to mate and the suppression of such mating behaviour by the male hierarchy exist contemporaneously. The masculine hierarchy is expressed territorially and hence in the number per harem (which may consist of from i to 100 females). The suppression of sexual approach is also expressed terri¬ torially in the neutral zones behind the foreshore and the channels between territories to the sea. The maturing male is only liable to threat when actually transgressing the territorial boundaries, and hence the visual social conflict is not continuous throughout the season, but is expressed in the exclusion, challenge and fighting that occurs between males. There are probably many examples in mammals of forms of resolution of social conflict, and it would be of considerable significance to have to hand more information about the societies of mammals. Also it is said that the seal has a large convoluted cortex, but this has not been adequately reported comparatively as yet, and hence information about the social life of animals together with comparative knowledge of their neuro-anatomy might give us considerably more information as to the functions and evolution of various parts of the nervous system. As a result of the prolonged mating provocation of the males in primate society, the appropriateness of mating behaviour for reproductive efficiency becomes dependent not only on adequate sexual behaviour, but on other forms of social behaviour. These we have seen are the ability to withstand conflict by equilibration and the control of aggression. How far is it possible to identify the anatomical features underlying these functions?