Wet- and dry-season steroid hormone profiles and stress reactivity of an insular dwarf snake, the Hog Island boa (Boa constrictor imperator).
Field endocrine studies providing new comparisons for inference into the evolutionary and ecological factors shaping organismal physiology are important, often yielding novel physiological insights. Here, we explored factors associated with the sex steroid hormone concentrations and adrenocortical response to capture stress in Hog Island boas (Boa constrictor imperator) in the Cayos Cochinos archipelago of Honduras to generate comparative field hormone data from a tropical reptile and test the island tameness hypothesis. Baseline concentrations of testosterone, corticosterone, estradiol, and progesterone were measured during the wet and dry seasons, and an acute stressor of 1 h in a cloth bag was used to assess the stress response. Plasma steroid concentrations in these snakes were generally low in comparison to other taxa. Higher testosterone concentrations in males and higher estradiol and corticosterone concentrations in females were observed during the wet season compared to the dry season, which may be indicative of mating activities and vitellogenesis during this period. Snakes displayed a 15-fold increase in corticosterone concentrations in response to capture stress, a rise that was not impacted by whether a snake had been captured during previous years. The adrenocortical stress response was greater in males and positively related to body temperature. We suggest that this system merits future inquiries into the physiology and behavior of B. c. imperator, particularly as a model for studying insular impacts on diverse life history characters.
Department of Biological Sciences, California Polytechnic State University, 1 Grand Avenue, San Luis Obispo, California 93407; 2Department of Biology, Truman State University, 100 East Normal Street, Kirksville, Missouri 63501; 3398 Carilla Lane, Columbus, Ohio, 43228; 4Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061.
Matthew L
ML
Holding
Julius A
JA
Frazier
Scott W
SW
Dorr
Nicholas B
NB
Pollock
P J
PJ
Muelleman
Amber
A
Branske
Sloane N
SN
Henningsen
Cas
C
Eikenaar
Camilo
C
Escallón
Chad E
CE
Montgomery
Ignacio T
IT
Moore
Emily N
EN
Taylor
D000818:Animals; D001831:Body Temperature; D017821:Boidae / Q000502:physiology*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006721:Honduras; D008297:Male; D012621:Seasons; D012737:Sex Factors; D013312:Stress, Physiological / Q000502:physiology*
D012739:Gonadal Steroid Hormones