Data from: Application of a novel molecular method to age free-living wild Bechstein’s bats

The age profile of populations fundamentally affects their conservation
status. Yet age is frequently difficult to assess in wild animals. Here,
we assessed the use of DNA methylation of homologous genes to establish
the age structure of a rare and elusive wild mammal: the Bechstein’s bat
(Myotis bechsteinii). We collected 62 wing punches from individuals whose
ages were known as a result of a long-term banding study. DNA methylation
was measured at seven CpG sites from three genes which have previously
shown age-associated changes in humans and laboratory mice. All CpG sites
from the tested genes showed a significant relationship between DNA
methylation and age, both individually and in combination (multiple linear
regression R2=0.58, p<0.001). Despite slight approximation around
estimates, the approach is sufficiently precise to place animals into
practically useful age cohorts. This method is of considerable practical
benefit as it can reliably age individual bats. It is also much faster
than traditional capture-mark-recapture techniques, with the potential to
collect information on the age structure of an entire colony from a single
sampling session to better inform conservation actions for Bechstein’s
bats. By identifying three genes where DNA methylation correlates with age
across distantly related species, this study also suggests that the
technique can potentially be applied across a wide range of mammals.