SGER - Hormones, Behavior and Life Cycles: Predictors of Sensitivity to Global Change?

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Global climate change is resulting in dramatic adjustments of migrations, breeding seasons and other aspects of the life cycle of organisms. Some populations flourish, others decline and yet others remain unchanged. Why this variation? A population of songbirds (White-crowned Sparrow, Zonotrichia leucophrys pugetensis) has recently been identified that has colonized urban habitat in Seattle as well as taken advantage of human disturbed areas in the Cascade Mountains of Washington State. These birds have settled in new habitat and their populations have expanded dramatically in the last twenty years. These populations are now in contact with alpine sub-species (Z.l. gambelii) that is not changing its range. Furthermore, there is a non-migratory, coastal sub-species (Z.l. nuttalli) that also is not changing its range. Accumulating data show that the sub-species that is changing its range is also changing hormone-behavior mechanisms to match the alpine sub-species. This includes the hormonal responses to stress. These responses are modulated up in the spring and down once nesting begins in the alpine and northern sub-species, but not modulated in the coastal sub-species (including the populations of Z.l. pugetensis in ancestral, coastal, habitat). Populations of Z.l. pugetensis that have colonized urban and alpine habitats now modulate their hormone responses to acute stress as do the northern and natural alpine sub-species. The current project will determine whether this is an epigenetic effect or rapid evolution of new traits. This will include potential epigenetic regulation of gene transcription in ancestral populations and pioneer populations of Z.l. pugetensis, compared with the sub-species Z.l. gambelii and Z.l. nuttalli that are not changing their ranges. This research will be a new blend of cell and molecular techniques in ecological settings in relation to global change. At least two graduate students will be involved in the field work and developing molecular methods for the epigenetic work. This project will likely become the focus for thesis research for these two students and undergraduate students will also join the project through this spring and summer.