Alternative reproductive tactics in female striped mice: solitary breeders have lower corticosterone levels than communal breeders

Hill, D. L. , Pillay, N. and Schradin, C. (2015) Alternative reproductive tactics in female striped mice: solitary breeders have lower corticosterone levels than communal breeders. Hormones and Behavior, 71, pp. 1-9. (doi: 10.1016/j.yhbeh.2015.03.004) (PMID:25828632)

Abstract

Alternative reproductive tactics (ARTs), where members of the same sex and population show distinct reproductive phenotypes governed by decision-rules, have been well-documented in males of many species, but are less well understood in females. The relative plasticity hypothesis (RPH) predicts that switches between plastic ARTs are mediated by changes in steroid hormones. This has received much support in males, but little is known about the endocrine control of female ARTs. Here, using a free-living population of African striped mice (Rhabdomys pumilio) over five breeding seasons, we tested whether females following different tactics differed in corticosterone and testosterone levels, as reported for male striped mice using ARTs, and in progesterone and oestrogen, which are important in female reproduction. Female striped mice employ three ARTs: communal breeders give birth in a shared nest and provide alloparental care, returners leave the group temporarily to give birth, and solitary breeders leave to give birth and do not return. We expected communal breeders and returners to have higher corticosterone, owing to the social stress of group-living, and lower testosterone than solitary breeders, which must defend territories alone. Solitary breeders had lower corticosterone than returners and communal breeders, as predicted, but testosterone and progesterone did not differ between ARTs. Oestrogen levels were higher in returners (measured before leaving the group) than in communal and solitary breeders, consistent with a modulatory role. Our study demonstrates hormonal differences between females following (or about to follow) different tactics, and provides the first support for the RPH in females.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hill, Dr Davina
• Authors: Hill, D. L., Pillay, N., and Schradin, C.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Hormones and Behavior
• Publisher: Elsevier
• ISSN: 0018-506X
• ISSN (Online): 1095-6867
• Published Online: 28 March 2015
• Copyright Holders: Copyright © 2015 Elsevier Inc
• First Published: First published in Hormones and Behavior 71:1-9
• Publisher Policy: Reproduced in accordance with the publisher copyright policy