Early life expenditure in sexual competition is associated with increased reproductive senescence in male red deer

Early life expenditure in sexual competition is associated with increased reproductive senescence in male red deer 
Jean-François Lemaître, Jean-Michel Gaillard, Josephine M. Pemberton, Tim H. Clutton-Brock and Daniel H. Nussey (2014)
Proceedings of the Royal Society B: Biological Sciences


Abstract

The evolutionary theories of senescence predict that investment in reproduction in early life should come at the cost of reduced somatic maintenance, and thus earlier or more rapid senescence. There is now growing support for such trade-offs in wild vertebrates, but these exclusively come from females. Here, we test this prediction in male red deer (Cervus elaphus) using detailed longitudinal data collected over a 40-year field study. We show that males which had larger harems and thereby allocated more resources to reproduction during early adulthood experienced higher rates of senescence in both harem size and rut duration. Males that carried antlers with more points during early life did not show more pronounced declines in reproductive traits in later life. Overall, we demonstrate that sexual competition shapes male reproductive senescence in wild red deer populations and provide rare empirical support for the disposable soma theory of ageing in males of polygynous vertebrate species.

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"[Although] high reproductive expenditure in early adulthood is associated with an increased rate of decline in late life, this decline is not sufficient to negate the phenotypic superiority of these males until extreme old age."

[N=118]