This project is concerned with basic mechanisms in the development and hormonal modulation of mammalian social behavior. For strategic reasons we plan to study a highly social carnivore, the spotted hyena (Crocuta crocuta), with a unique set of behavioral and morphological features. We are interested in the processes through which the following aspects of adult social behavior emerge during the period between infancy and puberty: (A) There is near absolute dominance of females over males in terms of access to food at a kill. (B) Female dominance persists in non-feeding situations. (C) Certain vocalizations, e.g., """"""""whoops"""""""", are more likely to be emitted by males than females. (D) Anal scent marking, a prominent feature of hyena behavior, is differentially emitted by males and females as a function of rank and context. (E) Socially cohesive behaviors (e.g., greeting ceremonies and close proximity) are common in like-sex dyads and rare in between-sex dyads. Field observations have provided these data, but are limited in terms of following individuals through development, or in the kinds of physiological work that can be undertaken. We therefore propose to establish four groups (""""""""clans"""""""") of hyenas. These eight member clans will be evenly divided as to sex and treatment condition (intact or gonadectomized). Through observation of animals in conditions designed to simulate activities at the den, during competitive feeding, and at territorial borders, we hope to trace the emergence of female dominance from early patterns of rough and tumble play, and the development of the highly sex, rank, and role-differentiated adult greeting ceremony from the generalized excitement of infant greetings. The latter typically involve erections in both male and female infants; a behavioral event made possible by the unusual development of external genitalia in female superficially identical to those of the male. Monthly assays of various hormones, in concert with gonadectomy data and replacement hormone studies, should provide us with significant information regarding activational and/or possible postnatal organizational effects of hormones.
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