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Effects of season, age and body condition on allocation to testes mass in Iberian ibex
Author(s) -
Sarasa M.,
Serrano E.,
Pérez J. M.,
Soriguer R. C.,
Gonzalez G.,
Joachim J.,
Fandos P.,
Granados J.E.
Publication year - 2010
Publication title -
journal of zoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0952-8369
DOI - 10.1111/j.1469-7998.2009.00689.x
Subject(s) - biology , ungulate , sperm competition , seasonal breeder , capra , sperm , sexual selection , competition (biology) , zoology , ecology , demography , habitat , botany , sociology
Sperm competition is a powerful evolutionary force, and understanding the factors that regulate testes characteristics may lead to a better understanding of the variability in male reproductive success. We explored the effects of age, body condition and season on relative testes mass in the Iberian ibex Capra pyrenaica . We analysed the variability of testes mass from 175 individuals, using a model selection approach based on Akaike's information criterion corrected for a small sample size. The results suggest that season, age and body condition influenced relative testes mass. Allocation to testes mass was greatest in the rutting season (autumn) and at ages that are associated with a subordinate status and a coursing, rather than mate‐guarding, reproductive strategy. In addition, males in good condition had relatively heavier testes than those in poor condition. Thus, testes mass in Iberian ibex is governed by multiple factors, and this study leads to a better understanding of gonad plasticity in this polygamous ungulate. The effect of age matches the predictions from theoretical studies on sperm competition, which suggests greater allocation to testes in disadvantaged males.