TY - JOUR
T1 - Circulating corticosterone levels vary during exposure to anthropogenic stimuli and show weak correlation with behavior across an urban gradient in house finches (Haemorhous mexicanus)
AU - Weaver, Melinda
AU - Gao, Sisi
AU - McGraw, Kevin
N1 - Funding Information:
This work was made possible by grants from Arizona State University Graduate and Professional Student Association, Sigma Xi, Animal Behavior Society, and the Central Phoenix-Arizona Long Term Ecological Project. We would like to thank the McGraw Lab “Super Brain,” Dr. Ron Rutowski, and reviewers for edits on this manuscript, labmate Pierce Hutton for enforcing deadlines and improving statistical methods, and Dr. Pierre Deviche and his graduate student Shelley Valle for providing lab space, comments and statistical help. This work would also not be possible without invaluable assistance in field work and CORT analysis from multiple Arizona State University undergraduates: Amber Bail, Courtney Baxter, Emily Boyle, Jacob Brill, Ellen Brooks, Madison Crump, Kayla Edwins, Ramzi El-Sayed, Laura Eyering, Mitchel Faas, Kali Fardell, Megan Feeney, Francisco Gonzalez, Yun-Pei Hsieh, Megan Ipson, Chelsei Irving, Farhan Iqbal, Brett Johnson, Rebecca Kervella, Amelia Lax, Alicia Marcell, Christine Martinez, Shane Maule, Shawn Maule, Vincenza Misseri, Autumn Moore-Barkus, Jerasimos Moschonas, Melanie Mousel, Nathanial Munoz, Armaghan Nasim, David Peifer, Forrest Pratt, Daniel Restrepo, Angela Riley, Kalie Rumaner, Sarah Shirota, Kyle Simmons, Princess Taylor, Maria Torres, Roberto Torres, Autumn Tullock, Paola Vivelo, Jeremiah Wetherby, Lauren Yanez, and Megan Zimmerman.
Publisher Copyright:
© 2018
PY - 2018/9/15
Y1 - 2018/9/15
N2 - Urban environments are rapidly expanding and presenting animal populations with novel challenges, many of which are thought to be stressors that contribute to low biodiversity. However, studies on stress responses in urban vs rural populations have produced mixed results, and many of these studies use a standard stressor that cannot be replicated in the wild (e.g. restraining an animal in a bag). Pairing physiological and behavioral measurements in response to urban-related stressors improves our understanding of the mechanism underlying animal success in human-dominated landscapes. Here, we examined the physiological stress (plasma corticosterone, CORT) responses of a songbird species (the house finch, Haemorhous mexicanus) to two different anthropogenic stimuli – (1) the presence of a human and (2) a captive environment containing man-made objects. During three field seasons (summer 2012, winter 2014, and winter 2015), we captured birds at six sites along an urban gradient in Phoenix, Arizona, USA and measured plasma CORT levels both before and after each trial. Though CORT levels did increase post-human exposure, though not during exposure to novel environment, indicating only one of the treatments caused a physiological response, baseline or post-trial plasma CORT levels did not differ between finches between urban and rural birds in 2012 or 2014. However, rural birds demonstrated relatively low pre- and post-trial plasma CORT levels during the human-exposure trials in 2015. Furthermore, we found few correlations between behavioral and physiological responses. A significant positive correlation was only detected between activity behavior after human approach and post-trial plasma CORT levels in 2012. Taken together, our results reveal a weak, conditional relationship between stress physiology, behavioral responses, and urbanization in house finches.
AB - Urban environments are rapidly expanding and presenting animal populations with novel challenges, many of which are thought to be stressors that contribute to low biodiversity. However, studies on stress responses in urban vs rural populations have produced mixed results, and many of these studies use a standard stressor that cannot be replicated in the wild (e.g. restraining an animal in a bag). Pairing physiological and behavioral measurements in response to urban-related stressors improves our understanding of the mechanism underlying animal success in human-dominated landscapes. Here, we examined the physiological stress (plasma corticosterone, CORT) responses of a songbird species (the house finch, Haemorhous mexicanus) to two different anthropogenic stimuli – (1) the presence of a human and (2) a captive environment containing man-made objects. During three field seasons (summer 2012, winter 2014, and winter 2015), we captured birds at six sites along an urban gradient in Phoenix, Arizona, USA and measured plasma CORT levels both before and after each trial. Though CORT levels did increase post-human exposure, though not during exposure to novel environment, indicating only one of the treatments caused a physiological response, baseline or post-trial plasma CORT levels did not differ between finches between urban and rural birds in 2012 or 2014. However, rural birds demonstrated relatively low pre- and post-trial plasma CORT levels during the human-exposure trials in 2015. Furthermore, we found few correlations between behavioral and physiological responses. A significant positive correlation was only detected between activity behavior after human approach and post-trial plasma CORT levels in 2012. Taken together, our results reveal a weak, conditional relationship between stress physiology, behavioral responses, and urbanization in house finches.
KW - Behavior
KW - Birds
KW - Boldness
KW - Exploration
KW - Plasticity
KW - Stress
KW - Urbanization
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U2 - 10.1016/j.ygcen.2018.04.017
DO - 10.1016/j.ygcen.2018.04.017
M3 - Article
C2 - 29673843
AN - SCOPUS:85046349442
SN - 0016-6480
VL - 266
SP - 52
EP - 59
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
ER -