Article

Early reproductive investment, senescence and lifetime reproductive success in female Asian elephants

Details

Citation

Hayward A, Mar KU, Lahdenpera M & Lummaa V (2014) Early reproductive investment, senescence and lifetime reproductive success in female Asian elephants. Journal of Evolutionary Biology, 27 (4), pp. 772-783. https://doi.org/10.1111/jeb.12350

Abstract
The evolutionary theory of senescence posits that as the probability of extrinsic mortality increases with age, selection should favour early-life over late-life reproduction. Studies on natural vertebrate populations show early reproduction may impair later-life performance, but the consequences for lifetime fitness have rarely been determined, and little is known of whether similar patterns apply to mammals which typically live for several decades. We used a longitudinal dataset on Asian elephants (Elephas maximus) to investigate associations between early-life reproduction and female age-specific survival, fecundity and offspring survival to independence, as well as lifetime breeding success (lifetime number of calves produced). Females showed low fecundity following sexual maturity, followed by a rapid increase to a peak at age 19 and a subsequent decline. High early life reproductive output (before the peak of performance) was positively associated with subsequent age-specific fecundity and offspring survival, but significantly impaired a female's own later-life survival. Despite the negative effects of early reproduction on late-life survival, early reproduction is under positive selection through a positive association with lifetime breeding success. Our results suggest a trade-off between early reproduction and later survival which is maintained by strong selection for high early fecundity, and thus support the prediction from life history theory that high investment in reproductive success in early life is favoured by selection through lifetime fitness despite costs to later-life survival. That maternal survival in elephants depends on previous reproductive investment also has implications for the success of (semi-)captive breeding programmes of this endangered species.

Keywords
ageing; antagonistic pleiotropy; disposable soma; reproductive costs, senescence; trade-off

Journal
Journal of Evolutionary Biology: Volume 27, Issue 4

StatusPublished
Publication date30/04/2014
Publication date online03/03/2014
Date accepted by journal25/01/2014
URLhttp://hdl.handle.net/1893/22903
PublisherWiley-Blackwell for European Society for Evolutionary Biology
ISSN1010-061X