The negative co‐variation of life‐history traits such as fecundity and lifespan across species
suggests the existence of ubiquitous trade‐offs. Mechanistically, trade‐offs result from the …

Fluctuations in abiotic and biotic conditions exist in almost all habitats (Dunlap, Loros, &
DeCoursey, 2004; Stevenson et al., 2015). Some fluctuations like the alternation between day …

Steroid hormones have similar functions across vertebrates, but circulating concentrations
can vary dramatically among species. We examined the hypothesis that variation in titres of …

Studies that blend a comparative approach to immunology with an appreciation for
physiological ecology are defining an important new field in biology—ecological immunology. …

Hormones mediate major physiological and behavioural components of the reproductive
phenotype of individuals. To understand basic evolutionary processes in the hormonal …

Hormones play a central role in integrating internal and external cues to help mediate life-history
decisions as well as changes in behavior and physiology of individuals. Describing the …

Hormones regulate decision-making strategies, in particular by translating an individual's
physiological state into decisions on major behavioural and life-history processes, such as …

Animals need to adjust reproductive decisions to environmental seasonality. In contrast to
species from the well-studied temperate zones, little is known for tropical birds about the …

Tropical wet forests are commonly perceived as stable and constant environments. However,
many rain forest organisms reproduce seasonally. To understand the proximate regulation …

Testosterone (T) regulates avian behaviors such as song and aggression during the breeding
season. However, the role of T in year-round territorial birds is still enigmatic, especially in …