A recent paper by Christina Dagmar Buesching and colleagues demonstrate two different endocrinological phenotypes in  wild European badgers, Meles meles. Type 1 males lower their testosterone levels after the end of the main mating season in winter, thus presumably saving energy and maintaining good body condition and low parasite loads, while type 2 continue to maintain high levels of circulating sex-steroids, staying in reproductive condition until late summer/ autumn. The researches found some evidence for the hypothesis that Type 1 males suffer higher early mortality rates and thus a lower life expectancy.