Birds have evolved seasonal adaptations in multiple aspects of the innate and adaptive
immune systems. Seasonal immunological adaptations are crucial for survival in harsh …

Phylogenetically controlled studies across multiple species correct for taxonomic confounds
in physiological performance traits. Therefore, they are preferred over comparisons of two or …

Climate change, habitat alteration, range expansions, and biological invasions are all
predicted to require rapid shifts in multiple traits including behavior and life history, both for …

Our understanding of avian growth rates can benefit from the use of two statistical
approaches that explicitly model the sources of intraspecific variation. First, random effects …

Interpopulation variation in territorial aggression can reflect differences in life history or
competitive environments. Life history theory predicts that males with more opportunities for …

Reproduction in vertebrates is an energy-demanding process that is mediated by
endogenous hormones and potentially results in oxidative stress. The primary aim of this …

Life history theory emphasizes the importance of trade‐offs in how time and energy are
allocated to the competing demands of growth, fecundity, and survival. However, avian …

Studies of birds have greatly advanced our understanding of how testosterone modulates
complex phenotypes, specifically its role in mediating male reproductive and associated …

Introduction In biparental birds testosterone levels of males are typically high during the
mating phase and decrease during the parental phase. Testosterone implants may enhance …

The steroid hormone testosterone not only plays an important role in gamete production, but
also influences social and aggressive behavior. Testosterone varies seasonally, peaking …