In numerous primates living in mixed-sex groups, females display probabilistic cues of
fertility to simultaneously concentrate paternity to dominant males while diluting it amongst …

Humans form agonistic coalitions and alliances in many contexts, but this behavior is
thought to be rare in other species. A prominent hypothesis states that coalitions may be …

White-handed gibbons usually live in monogamous pairs, but at Khao Yai National Park,
Thailand groups often contain two adult males. We studied mating and sexual behaviour (ie …

Androgens play a role in male reproductive competition, frequently via aggression, while
glucocorticoids are associated with the stress response. However, the relationships of these …

Parallel dispersal occurs when individuals emigrate together with peers or close kin, or
immigrate into groups containing familiar or closely related individuals. To understand the …

Female primates signal impending ovulation with a suite of sexual signals. Studies of these
signals have focussed on visual, and to a lesser extent, acoustic signals, neglecting olfactory …

Objectives Raising offspring imposes energetic costs, especially for female mammals.
Consequently, seasons favoring high energy intake and sustained positive energy balance …

Empathy probably guides most hypotheses about social behaviour (Hrdy, 1986), or at least
the amount of attention given to particular problems. For several decades now, behavioural …

Among nonhuman primates, male reproductive skew (ie, the distribution of reproductive
success across males) appears to be affected primarily by receptive synchrony and the …

We investigated hormonal and behavioral changes in wild male and female northern
muriquis (Brachyteles arachnoides hypoxanthus) at the Estação Biológica de Caratinga …