
Michelle Cawthorn
Associate Professor Georgia Southern University
- Statesboro GA
Professor Cawthorn specializes in the ecology and behavior of small mammals such as shrews and small mice
Biography
Areas of Expertise
Education
Bowling Green State University
Ph.D.
Old Dominion University
M.S.
Articles
Influence of experimentally elevated testosterone on nest defence in dark-eyed juncos
Animal BehaviourJM Cawthorn, DL Morris, ED KETTERSON, et al.
1998
Testosterone affects the allocation of reproductive effort in male birds. Elevated testosterone causes male dark-eyed juncos,Junco hyemalis, to decrease care of dependant offspring, but this generalization is based largely on reduced provisioning rates by males treated with testosterone. Therefore, we used a predator model to explore the relationship between testosterone and nest defence, a more immediate measure of male parental effort. Control males (C-males) were more likely to respond within 10 min to a mount of an eastern chipmunk,Tamias striatus, placed at the nest than were testosterone-treated males (T-males)...
Effects of Experimentally Elevated Testosterone on Plasma Corticosterone and Corticosteroid-Binding Globulin in Dark-Eyed Juncos ( Junco hyemalis)
General and Comparative EndocrinologyLA Klukowski, JM Cawthorn, ED Ketterson, et al.
1997
An earlier study of free-living male dark-eyed juncos found an increase in plasma corticosterone (B) in response to experimental elevation of plasma testosterone (T) (E. D. Kettersonet al.,1991,Horm. Behav.25,489–503). To investigate whether the increase was caused by enhanced secretion of corticosterone or by a slower clearance rate, or both, we exposed 52 captive yearling male dark-eyed juncos (Junco hyemalis) to day lengths corresponding to those of spring and implanted them with one or two testosterone-filled or sham implants (10 T-I, 22 T-II, and 20 C-males). We then examined the effect of experimentally elevated testosterone on plasma corticosterone and on corticosteroid-binding globulin (CBG), as measured by the ability of steroid-stripped plasma to bind labeled corticosterone...