Data from: Getting ready for the winter: timing and determinants of molt in an alpine ungulate

Because growth of new hairs entails energetic costs, individual condition
and access to food should determine the timing of molt. Previous studies
on the timing of molt in ungulates have mostly focused on the influence of
age-class and reproductive status, but the effects of body condition and
environmental phenology have not been evaluated. Our goal was to assess
how intrinsic traits and environmental conditions determine the timing of
winter coat shedding in a mountain goat population monitored for 27 years.
The date of molt completion followed a U-shape with age, suggesting that
senescence occurs in terms of the molting process in mountain goats.
Juveniles of both sexes delayed molting in a similar fashion, but molt
timing differed between sexes during adulthood. Males molted progressively
earlier until reaching age when reproduction peaked, after which they
started delaying molting again. Females reached earliest molt dates at age
of first reproduction and then progressively delayed molt date. Lactating
females molted 10 days later than barren females on average, but this only
occurred in females in good condition. Thus, although it has been shown
that reproduction delays molt in ungulates, our results indicate that body
condition can override this effect. Overall, our results revealed that
access to both extrinsic and intrinsic resources is one of the key
mechanisms driving molting processes in a mammalian herbivore.