Research Interests:
I am classically trained as a physiologist although my interests have broadened over the past several years to include ecology and behavior. I am particularly interested in how organisms integrate environmental information in order to control the expression and progression through life history stages (ie migration, breeding, molt, etc). As a field biologist, I have come to appreciate that any one particular discipline within biology is not independent from another. For instance, it is impossible to separate physiology from ecology, behavior from physiology, etc. Consequently, I strive to study physiology with the ecology of the bird in mind. As an endocrinologist, I am particularly interested in how physiology and behavior are controlled through endocrine signaling mechanisms.
My research has focused on the regulation of stress, reproduction, and the interface between these two systems in White-crowned sparrow (Zonotrichia leucophrys) and Lapland longspurs (Calcarius lapponicus). Birds, as with many other species across a broad range of taxa, use the endocrine system to appropriately time reproduction while dealing with environmental challenges (predation, storms, food shortages, etc). The importance of the interplay between these two systems is becoming more evident as animals deal with a changing environment either through climate change or encroachment by urbanization. Seasonally breeding animals are under a strong selective pressure to breed at the appropriate time of year in order to ensure high fecundity. This has resulted in selection and utilization of key environmental signals, such as photoperiod, to control endocrine signaling cascades for various physiological processes including reproduction. However, environmental stressors can impair the reproductive axis through the secretion of the stress hormone corticosterone. I am particularly interested in how evolution in white-crowned sparrows has shaped different life history strategies through physiological control mechanism with a focus on endocrinology. I am currently working to understand the hypothalamic pituitary adrenal axis differs between these two species by investigating the expression of steroid receptors, steroid metabolizing enzymes, transport proteins, peptide hormones, etc. We have been able to identify dramatic differences in hormone signaling in some instances while in others they are remarkably conserved. I, along with my coauthors, are in the process of finalizing a set of manuscripts investigating this work.
As our previous work comes to a close, I am gearing up to better understand the physiological changes that occur during migration. We are sampling resident and migrant white-crowned sparrows at the key transition points between migration and nonmigrating stages of the annual cycle and during migration. I am using the resident as a control group to understand how physiology differs in the migrant subspecies. Our analysis will allow us to understand both subspecies differences but also changes across the annual cycle within a subspecies. I am still interested in the stress physiology associated with migration but I want to expand the investigation to better understand the metabolic tissues during migration. In particular, work on adipose tissue from our previous grant highlights its dynamic nature and will be an interesting target for future investigation.
My research has focused on the regulation of stress, reproduction, and the interface between these two systems in White-crowned sparrow (Zonotrichia leucophrys) and Lapland longspurs (Calcarius lapponicus). Birds, as with many other species across a broad range of taxa, use the endocrine system to appropriately time reproduction while dealing with environmental challenges (predation, storms, food shortages, etc). The importance of the interplay between these two systems is becoming more evident as animals deal with a changing environment either through climate change or encroachment by urbanization. Seasonally breeding animals are under a strong selective pressure to breed at the appropriate time of year in order to ensure high fecundity. This has resulted in selection and utilization of key environmental signals, such as photoperiod, to control endocrine signaling cascades for various physiological processes including reproduction. However, environmental stressors can impair the reproductive axis through the secretion of the stress hormone corticosterone. I am particularly interested in how evolution in white-crowned sparrows has shaped different life history strategies through physiological control mechanism with a focus on endocrinology. I am currently working to understand the hypothalamic pituitary adrenal axis differs between these two species by investigating the expression of steroid receptors, steroid metabolizing enzymes, transport proteins, peptide hormones, etc. We have been able to identify dramatic differences in hormone signaling in some instances while in others they are remarkably conserved. I, along with my coauthors, are in the process of finalizing a set of manuscripts investigating this work.
As our previous work comes to a close, I am gearing up to better understand the physiological changes that occur during migration. We are sampling resident and migrant white-crowned sparrows at the key transition points between migration and nonmigrating stages of the annual cycle and during migration. I am using the resident as a control group to understand how physiology differs in the migrant subspecies. Our analysis will allow us to understand both subspecies differences but also changes across the annual cycle within a subspecies. I am still interested in the stress physiology associated with migration but I want to expand the investigation to better understand the metabolic tissues during migration. In particular, work on adipose tissue from our previous grant highlights its dynamic nature and will be an interesting target for future investigation.
