Elevated testosterone levels can lower condition and increase parasites. We analysed testosterone in 84 blood samples of wild
European badgers
Meles meles collected at regular intervals (winter = mating season; spring = end of mating season; summer = minor mating peak; autumn = reproductive
quiescence), and related variation to body condition, subcaudal gland secretion, parasite burden, and bite wounding. All males
showed elevated levels in winter and low levels in autumn. In neither season did testosterone correlate with fitness-related
parameters. However, two different endocrinological phenotypes existed in spring and summer. Whilst some males lowered their
testosterone to levels comparable to autumnal quiescence (Type 1), others maintained elevated levels comparable to those during
winter (Type 2). In spring and summer high levels were correlated with lower body condition and increased parasite burden,
and Type 2 males tended to suffer higher mortality rates than Type 1. No animals older than 6 years adopted phenotype 2, indicating
that males either switch phenotypes with age or that Type 2 results in lower life expectancy, evidencing the costs of male
reproduction in badgers.
Keywords Badger -
Meles meles
- Testosterone - Reproductive strategies - Seasonality