Sex ratio bias, male aggression, and population collapse in lizards.

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State: Public
Version: Final published version
Serval ID
serval:BIB_249E29EBC6DC
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Sex ratio bias, male aggression, and population collapse in lizards.
Journal
Proceedings of the National Academy of Sciences of the United States of America
Author(s)
Le Galliard J.F., Fitze P.S., Ferrière R., Clobert J.
ISSN
0027-8424 (Print)
ISSN-L
0027-8424
Publication state
Published
Issued date
2005
Peer-reviewed
Oui
Volume
102
Number
50
Pages
18231-18236
Language
english
Abstract
The adult sex ratio (ASR) is a key parameter of the demography of human and other animal populations, yet the causes of variation in ASR, how individuals respond to this variation, and how their response feeds back into population dynamics remain poorly understood. A prevalent hypothesis is that ASR is regulated by intrasexual competition, which would cause more mortality or emigration in the sex of increasing frequency. Our experimental manipulation of populations of the common lizard (Lacerta vivipara) shows the opposite effect. Male mortality and emigration are not higher under male-biased ASR. Rather, an excess of adult males begets aggression toward adult females, whose survival and fecundity drop, along with their emigration rate. The ensuing prediction that adult male skew should be amplified and total population size should decline is supported by long-term data. Numerical projections show that this amplifying effect causes a major risk of population extinction. In general, such an "evolutionary trap" toward extinction threatens populations in which there is a substantial mating cost for females, and environmental changes or management practices skew the ASR toward males.
Keywords
Aggression/physiology, Animals, Computer Simulation, Demography, Female, France, Lizards/physiology, Male, Models, Theoretical, Population Dynamics, Sex Ratio
Pubmed
Web of science
Open Access
Yes
Create date
24/11/2010 15:21
Last modification date
20/08/2019 13:02
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