No energetic cost of tuberculosis infection in European badgers (Meles meles)

1.Energy availability and energy use directly influence an organism's life history, fitness and ecological function. In wild animals, abiotic factors such as ambient temperature, season and rainfall, and biotic factors such as body mass, age, social group size and disease status, all potentially influence energy balance. 2.Relatively few studies have examined the effects of disease on the energy expenditure of wild animals. Such studies could further our understanding of factors influencing the transmission of zoonotic diseases. The European badger (Meles meles) is a medium-sized carnivore that occurs in mixed-sex, familial groups across much of its range. In the UK they are a protected species but are also involved in the epidemiology of bovine tuberculosis (TB) in cattle. 3.We measured the daily energy expenditure (DEE) and resting metabolic rate (RMR) of wild badgers and related this to their TB infection status and a range of other interacting factors including season, group size, disease status, sex, age, body mass and body fat. 4.Individuals were larger and fatter when they were older and fatter during the winter. Males were also heavier than females during the summer. In addition, individuals from smaller groups that were exposed to TB tended to have lower body mass. 5.There were no direct effects of disease status on DEE or RMR, however, there was a significant interaction whereby DEE increased with body mass in small groups but decreased with body mass in large groups. 6.Results are consistent with the costs of TB infection being met by compensatory mechanisms enabling badgers to survive for extended periods without exhibiting measurable energetic consequences. This article is protected by copyright. All rights reserved.