Graduation Date

Summer 2018

Document Type



Master of Science degree with a major in Natural Resources, option Wildlife

Committee Chair Name

Dr. Jared Wolfe

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Kristin Brzeski

Second Committee Member Affiliation

Community Member or Outside Professional

Third Committee Member Name

Dr. Luke Powell

Third Committee Member Affiliation

Community Member or Outside Professional

Fourth Committee Member Name

Dr. Daniel Barton

Fourth Committee Member Affiliation

HSU Faculty or Staff

Fifth Committee Member Name

Matthew Johnson

Fifth Committee Member Affiliation

HSU Faculty or Staff

Subject Categories



Environmentally-induced stress can initiate a molecular response through DNA methylation, which can alter gene expression, thereby serving as a mechanism allowing individuals to acclimate to a changing environment within their lifetime. In addition to DNA methylation, the production and release of corticosterone is a physiological mechanism by which birds can cope with acute environmental stressors. To assess how environmental stress impacted DNA methylation and corticosterone, I collected blood and feather samples from three understory avian species (Alethe castanea, Bleda notatus and Pseudalethe poliocephala), along a disturbance gradient in the lowland Guinean rainforest adjacent to the village of Oyala, Equatorial Guinea. I used two binomial mixed-effect models for each species to identify gene loci that were differentially methylated with respect to the amount of corticosterone deposited in a tail feather and distance to forest edge when captured. I identified 195, 126 and 246 sites differentially methylated by feather CORT and 296, 166 and 254 sites differentially methylated by distance to forest edge for Alethe castanea, Bleda notatus and Pseudalethe poliocephala, respectively. I also found a significant negative relationship between feather CORT and overall feather brightness indicating there may be trade-offs between coping with environmental stressors and fitness. I found substantial variation in CORT and DNA methylation along the disturbance gradient, suggesting that environmentally-induced molecular and endocrinological responses are prevalent in degraded tropical forests.

Citation Style

Journal of Wildlife Management


Thesis/Project Location