In general, my research examines how animals interact with their environment. In particular, I am interested in how hormones modulate physiological responses to environmental stimuli and how these physiological responses affect reproduction and survival and, ultimately, drive population and evolutionary responses.
Developing animals are particularly susceptible to environmental effects. As such, the developmental environment can have strong, canalizing effects on animal phenotype. A component of my research examines the phenotypic and fitness effects of exposure to stress during development. Developing animals are susceptible to perturbations to their environment such as food availability, exposure to ‘stress’ hormones, or anthropogenic disturbances. My research examines the immediate and sustained phenotypic and fitness effects of developmental stress across life-history stages using birds as a model system.
As the human population grows at an increasing rate, so does our impact on the environment. Understanding how humans affect wildlife is becoming a matter of increasing importance for conservation and management. I use physiological tools to assess the impacts of humans on the health, survival, and reproduction of wild birds. A component of my research in this areas has examined the effects of roads on avian communities outside Yosemite national Park, California. Roads impact ecosystems by fragmenting habitat, increasing land use by people, causing road mortality of wildlife, and altering the composition of native plant and animal communities. Roads have also been shown to increase glucocorticoid stress hormones in multiple taxonomic groups. My research in this area focuses on the effects of roads on white-crowned sparrows (Zonotrichia leucophrys oriantha).
A second component of my research in the field of conservation physiology focuses on the effects of mining activity on the endangered Gouldian finch (Erythrura gouldiae) in the Northern Territory, Australia. I am currently working with collaborators to understand how disturbances associated with mining activity affect stress hormone levels in Gouldian finches.
Stress hormones and reproduction in birds
Animals balance the energetic demands of survival against the energetic demands of reproduction. I study the role of glucocorticoid hormones in modulating the investment between self-maintenance and reproduction using Australian birds as model species.