Skin temperature and reproductive condition in wild female chimpanzees

Guillaume Dezecache; Claudia Wilke; Nathalie Richi; Christof Neumann; Klaus Zuberbühler

doi:10.7287/peerj.preprints.3041v1

Skin temperature and reproductive condition in wild female chimpanzees

Guillaume Dezecache ^1,2, Claudia Wilke^2,3,4, Nathalie Richi^1,2, Christof Neumann¹, Klaus Zuberbühler^1,2,3

1 Institute of Biology, Université de Neuchâtel, Neuchâtel, Switzerland

2 Budongo Conservation Field Station, Masindi, Uganda

3 School of Psychology and Neuroscience, University of St. Andrews, Fife, United Kingdom

4 Department of Psychology, University of York, York, United Kingdom

DOI: 10.7287/peerj.preprints.3041v1

Published: 2017-06-22
Accepted: 2017-06-22

Subject Areas: Animal Behavior, Zoology
Keywords: infra-red thermography, skin temperature, wild chimpanzees, oestrous cycle, pregnancy

Copyright: © 2017 Dezecache et al.
Licence: This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.

Cite this article: Dezecache G, Wilke C, Richi N, Neumann C, Zuberbühler K. 2017. Skin temperature and reproductive condition in wild female chimpanzees. PeerJ Preprints 5:e3041v1 https://doi.org/10.7287/peerj.preprints.3041v1

Abstract

Infrared thermal imaging has emerged as a valuable tool in veterinary medicine, in particular in evaluating reproductive processes. Here, we explored differences in skin temperature of cycling and pregnant wild chimpanzee females in Budongo Forest, Uganda. Based on previous literature, we predicted increased skin temperature when approaching peak fertility at the area of the reproductive organs of cycling females. For pregnant females, we made the same prediction, mainly because it has been argued that chimpanzee females have evolved mechanisms to conceal pregnancy, including exaggerated sexual swelling and sexually conspicuous vocal behaviour, and to encourage male mating behaviour in order to decrease their infanticidal tendencies by confusing paternity. Overall, we found only small changes in cycling females, with slight temperature increases towards the end of the swelling cycles but no overall increase in skin temperature between oestrous and non-oestrous phases. Interestingly, however, pregnant and cycling females had very similar skin temperatures. These results suggest that males cannot use skin temperature to discriminate between pregnant and non-pregnant/cycling females during maximal swelling, when ovulation is most likely to occur in cycling females. This pattern may be linked to the evolution of physiological means to conceal reproductive state in pregnant females.