Data from: The cost of growing large: sex-specific costs of post-weaning growth on body mass senescence in a wild mammal

Individual body mass often positively correlates with survival and
reproductive success, whereas fitness costs of growing large are rarely
detected in vertebrates in the wild. Evidence that adult body mass
progressively declines with increasing age is accumulating across
mammalian populations. Growing fast to a large body can increase the
cellular damage accumulated throughout life, leading body growth in early
life to be negatively associated with the rate of body mass senescence.
Moreover, the onset of mass senescence may strongly depend on both
sex-specific reproductive tactics and environmental conditions. Assessing
the timing and the rate of body mass decline with increasing age thus
offers an opportunity to look for costs of having grown fast, especially
after a poor start during early life, in both sexes and in different
environments. Using a unique dataset including 30 years of longitudinal
data on age-specific body mass collected in two roe deer Capreolus
capreolus populations subjected to contrasted environmental conditions, we
looked for potential costs of high post-weaning growth rate in terms of
steeper rate of body mass senescence. Our analyses of body mass senescence
accounted for the potential variation in the onset of senescence and
allowed explicit comparisons of this variable between sexes and
populations. Higher growth rates late in the growing period (after
weaning) were associated with a steeper rate of body mass senescence,
regardless of early mass (gained before weaning), but at different extents
depending on sex and environmental conditions. Body mass senescence
occurred earlier in males than in females, especially in the population
facing limiting resources. In the wild, although heavy individuals
generally survive better than small ones, the costs of growing large late
in the growing period only became apparent late in life through mass
senescence.