Multiple measures elucidate glucocorticoid responses to environmental variation in predation threat |
| |
Authors: | Michael Clinchy Liana Zanette Thierry D Charlier Amy E M Newman Kim L Schmidt Rudy Boonstra Kiran K Soma |
| |
Institution: | 1.Department of Biology,University of Victoria,Victoria,Canada;2.Department of Biology,University of Western Ontario,London,Canada;3.GIGA Neurosciences,University of Liège,Liège,Belgium;4.Department of Psychology,University of British Columbia,Vancouver,Canada;5.Centre for the Neurobiology of Stress,University of Toronto at Scarborough,Toronto,Canada |
| |
Abstract: | Predator-induced changes in the glucocorticoid responses of prey have been proposed to mediate indirect predator effects on
prey demography. Ambiguities exist, however, as to whether differences in predation threat in the environment at large affect
the mean glucocorticoid response in wild birds and mammals, and whether this is likely to affect reproduction. Most studies
to date that have examined glucocorticoid responses to environmental variation in predation threat have evaluated just one
of the several potential measures of the glucocorticoid response, and this may be the source of many ambiguities. We evaluated
multiple measures of the glucocorticoid response plasma total CORTicosterone, corticosteroid binding globulin (CBG) and free
CORT] in male and female song sparrows (Melospiza melodia) sampled at locations differing in predation threat in the environment at large, where we have previously reported reproductive
differences suggestive of indirect predator effects. Total CORT varied markedly with predation threat in males but not females
whereas the opposite was true for CBG, and both sexes demonstrated the same moderately significant free CORT response. Considering
all three indices, a glucocorticoid response to environmental variation in predation threat was evident in both sexes, whereas
there were ambiguities considering each index singly. We conclude that collecting multiple physiological measures and conducting
multivariate analyses may provide a preferable means of assessing glucocorticoid responses to environmental variation in predation
threat, and so help clarify whether such glucocorticoid changes affect reproduction in wild birds and mammals. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|