Anosmia and aggression in male owl monkeys (Aotus trivirgatus).

Adult owl monkeys behaved aggressively when paired with unfamiliar members of the same sex. Males showed the greatest aggressive responses. When plugs containing bismuth iodoform paste were inserted into the nasal passages of male owl monkeys they fought less readily and showed less contact aggression. Although intermale aggression was not abolished anosmic males spent longer in proximity and showed an increase in olfactory inspections. Control experiments confirmed that the technique used to induce anosmia had blocked responsiveness to conspecific odours and that decreases in aggression were not due to discomfort or non-specific behavioral effects.