Meeting Abstract
The energetic costs associated with acute phase response (APR), an integral component of the innate immune system, are thought to be high. Life-history theory predicts a trade-off between these costs and the energy invested in other life-history traits as well as an association with the slow-fast continuum of life-history strategies. Here we examine the energetic costs associated with APR in bats. Bats have a slow life-history pattern and co-evolved with lethal pathogens without any impact on their fitness. We expect that APR would be present in bats, but its costs would be lower than for fast-living rodents and slow-living birds. To test this hypothesis we measured the metabolic rate (MR) and body mass change of 3 species of Neotropical bats after challenging their immune system with lipopolysaccharide (LPS). For two of these species we also measured body temperature (Tb). APR was presented in bats as they increased MR and Tb and lost body mass after LPS administration. Mass-corrected MR of bats after LPS increased by the same amount as observed in rodents and birds. The total energetic costs associated with APR represents 1 to 8% of their total energy budgets. APR is present in bats and, like in most birds and rodents, its entail an increase in MR. However, the energetic costs associated with this response seems not to jeopardize their energy budgets. Thus it seems that differences in the life history continuum per se cannot explain differences in the costs of APR between bats, rodents and birds.
