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Testosterone and Aggression in Male Red Jungle Fowl

1995; Elsevier BV; Volume: 29; Issue: 4 Linguagem: Inglês

10.1006/hbeh.1995.1288

1095-6867

Torgeir S. Johnsen, Marlene Zuk,

Animal Nutrition and Physiology

We investigated the relationship between aggression, plasma testosterone level (T), and change in T in captive male red jungle fowl (Gallus gallus). T measured on day 1 of our experiment was positively correlated with T on day 8, suggesting that T remains constant in males when the social environment is stable. During aggressive encounters that escalated to include physical combat, males that attacked first (won) had increased T relative to their opponent. Males did not differ in T measured 1 week before the aggressive encounter. Our data suggest that an increase in T during aggression is associated with winning in escalated fights.