Disentangling the effects of neutral and adaptive processes in maintaining phenotypic variation across environmental gradients is challenging in natural populations. Song sparrows (Melospiza melodia) on the California ...

Abstract Large body size is an important determinant of individual fitness in many animal species, especially in island systems where habitat saturation may result in strong intraspecific competition for mates and breeding ...

Spatial and temporal variation in resource abundance and predation risk can favor the evolution of phenotypic plasticity as a means of tracking changing environments. However, because food abundance and predation risk often ...

Historical ecology provides information needed to understand contemporary conditions and make science-based resource management decisions. Gaps in historical records, however, can limit inquiries and inference. Unfortunately, ...

Avian incubation provides an opportunity to test how parental behavior and ecological conditions interact to shape variation in offspring traits along geographic gradients. In particular, the duration of the incubation ...

Orange-crowned warblers, Leiothlypis celata sordida, breeding on the California Channel Islands exhibit remarkable variation in their nest structure and placement, providing an intriguing exception to the general pattern ...

Males of some oscine passerines learn and share songs of neighboring males. This process can lead to the formation of song pattern neighborhoods or microhabitat song dialects. The degree to which song sharing occurs between ...

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 have historically emphasized the importance ...