Summary 1 Contests may involve injurious fighting, other types of direct physical aggression
and communication. They occur over ownership access to mates and other resources that …

The bi-directional links between hormones and behavior have been a rich area of research
for decades. Theory on the evolution of testosterone (T) was greatly advanced by the …

Although glucocorticoid hormones are considered important physiological regulators for
surviving adverse environmental stimuli (stressors), evidence for such a role is sparse and …

Social hierarchies emerge when animals compete for access to resources such as food,
mates or physical space. Wild and laboratory male mice have been shown to develop linear …

Monitoring the impact of anthropogenic disturbance on species or populations of interest is
an important goal of conservation (Van Dyke 2008). Because the effects of environmental …

A central tenet of life-history theory is that investment in reproduction compromises survival.
We tested for costs of reproduction in wild brown anoles (Anolis sagrei) by eliminating …

Testosterone is a key hormone for the development of secondary sexual characters and
dimorphisms in behavior and morphology of male vertebrates. Because females often …

Female–female aggression often functions in competition over reproductive or social
benefits, but the proximate mechanisms of this apparently adaptive behaviour are not well …

Winning aggressive social encounters can enhance the probability of future victories. This
so-called winner effect occurs in diverse species and is thought to be an intrinsic …

Testosterone is assumed to be the key hormone related to resource-defence aggression.
While this role has been confirmed mostly in the context of reproduction in male vertebrates …