2 research outputs found
Analyses of ovarian activity reveal repeated evolution of post-reproductive lifespans in toothed whales
This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordIn most species the reproductive system ages at the same rate as somatic tissue and individuals
continue reproducing until death. However, females of three species – humans, killer whales and
short-finned pilot whales – have been shown to display a markedly increased rate of reproductive
senescence relative to somatic ageing. In these species, a significant proportion of females live
beyond their reproductive lifespan: they have a post-reproductive lifespan. Research into this puzzling
life-history strategy is hindered by the difficulties of quantifying the rate of reproductive senescence
in wild populations. Here we present a method for measuring the relative rate of reproductive
25 senescence in toothed whales using published physiological data. Of the sixteen species for which
26 data are available (which does not include killer whales), we find that three have a significant post27
reproductive lifespan: short-finned pilot whales, beluga whales and narwhals. Phylogenetic
reconstruction suggests that female post-reproductive lifespans have evolved several times
independently in toothed whales. Our study is the first evidence of a significant post-reproductive
lifespan in beluga whales and narwhals which, when taken together with the evidence for post31
reproductive lifespan in killer whales, doubles the number of non-human mammals known to exhibit
post-reproductive lifespans in the wild.Support for this research was provided by a grant from NERC (NE/K01286X/1) awarded to DPC, DWF and MAC