ORIGINAL RESEARCH article
Uncovering the Sex-specific Endocrine Responses to Reproduction and Parental Care
- 1Department of Integrative Biology, College of Science, Oregon State University, United States
- 2Department of Fisheries and Wildlife, College of Agricultural Sciences, Oregon State University, United States
- 3Department of Neurobiology, Physiology, and Behavior, University of California, Davis, United States
- 4Department of Biology, College of Science, University of Nevada, Reno, United States
- 5UMR7372 Centre d'études biologiques de Chizé (CEBC), France
- 6Department of Molecular, Cellular and Biomedical Sciences, College of Liberal Arts, University of New Hampshire, United States
Hormones mediate physiological and behavioral changes in adults as they transition into reproduction. In this study, we characterize the circulating levels of five key hormones involved in reproduction in rock doves (Columba livia): corticosterone, progesterone, estradiol, testosterone, and prolactin using univariate and multivariate approaches. We show similar patterns as previous studies in the overall patterns in circulating levels of these hormones, i.e., testosterone (males) and estradiol (females) high during nest-building or egg-laying, prolactin increasing at mid-incubation and peaking at hatching (both sexes), and elevated corticosterone levels in later incubation and early nestling development. In our investigation of hormone co-variation, we find a strong correlation between prolactin and corticosterone across sampling stages and similarities in earlier (early to mid-incubation) compared to later (late incubation to nestling d9) sampling stages in males and females. Finally, we utilized experimental manipulations to simulate nest loss or altered caregiving lengths to test whether external cues, internal timing, or a combination of these factors contributed most to hormone variation. Following nest loss, we found that both males and females responded to the external cue. Males generally responded quickly following nest loss by increasing circulating testosterone, but this response was muted when nest loss occurred early in reproduction. Similar treatment type, e.g., removal of eggs, clustered similarly in hormone space. These results suggest internal drivers limited male response early in reproduction to nest loss. In contrast, circulating levels of these hormones in females either did not change or decreased circulating levels following nest manipulation suggesting responsiveness to external drivers, but unlike males, this result suggests that reproductive processes were decreasing.
Keywords: Reproduction, Birds, Prolactin, Corticosterone, sex steroids
Received: 20 Nov 2020;
Accepted: 30 Aug 2021.
Copyright: © 2021 Austin, Krause, Viernes, Farrar, Booth, Harris, Angelier, Lee, Bond, Wingfield, MacManes and Calisi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Suzanne Austin, Department of Integrative Biology, College of Science, Oregon State University, Corvallis, 97331, Oregon, United States, email@example.com