The Effects of Acoustic Signals on the Endocrine Physiology of Female Green Treefrogs, Hyla Cinerea

Dent, Melissa Paige (2015) The Effects of Acoustic Signals on the Endocrine Physiology of Female Green Treefrogs, Hyla Cinerea. Undergraduate thesis, under the direction of Chris Leary from Biology, University of Mississippi.

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Abstract

The vocalizations of male H. cinerea stimulate cortisol production in male receivers during close-range interactions. In many vertebrate species, males and females possess similar sensory neuroendocrine pathways, suggesting that acoustic signals may also stimulate CORT production in females. Males of this species would potentially benefit from stimulating CORT production in females because elevated CORT levels significantly decrease the strength of female preferences for energetically costly calls (i.e., calls produced at rapid rates). The primary objective of my honors research was to assess how the acoustic signals produced by male green treefrogs, Hyla cinerea, influence the endocrine physiology of female signal receivers. Specifically, I assessed how male acoustic signals alter circulating levels of stress hormones (i.e., glucocorticoids) in females. My results were unexpected in that advertisement calls actually decreased circulating levels of CORT in female receivers, indicating that males do not manipulate the stress physiology of females in ways that would allow them to gain access to females. My research thus suggests that there are neuroendocrinological differences between males and females that result in very different endocrine responses to the same acoustic signals. Another interesting outcome that emerged from my data involved the effect of aggressive calls on the endocrine physiology of females. Results indicated that exposure to aggressive calls resulted in decreased levels of progesterone and a marginally significant reduction in estradiol. These results may explain why males of this species only use aggressive signals in the context of male-male interactions; female reception of aggressive calls would decrease hormones associated with female sexual behavior, and thus decreases the likelihood of reproductive success for calling males.

Item Type: Thesis (Undergraduate)
Creators: Dent, Melissa Paige
Student's Degree Program(s): B.A. in Biology
Thesis Advisor: Chris Leary
Thesis Advisor's Department: Biology
Institution: University of Mississippi
Subjects: Q Science > Q Science (General)
Depositing User: Melissa Dent
Date Deposited: 12 May 2015 18:39
Last Modified: 12 May 2015 18:39
URI: http://thesis.honors.olemiss.edu/id/eprint/458

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