Meeting Abstract
Humans can negatively impact wildlife behavior and physiology by altering the habitats in which wild animals dwell. Host competence, or the propensity to generate infection in another individual, is determined by behavioral and physiological traits that mitigate exposure to and the ability to cope with infectious organisms. Here, we asked whether light pollution, which inflicts hormonal dysregulation, altered immune responses, and corresponding organismal fitness loss in other species, affects avian host competence for West Nile virus (WNV). Although house sparrows (a competent reservoir species for WNV) did not experience hormonal dysfunction in response to light pollution, light pollution caused sparrows to maintain WNV titers above 105 PFU (the transmission threshold to biting mosquitoes) for 2 days longer than controls. Light pollution also had no effects on tolerance of infection (i.e., the ability of individuals to maintain body mass when infected) or WNV-associated mortality. The combined effects of extended infectious duration in the absence of poor health or increased morality could exacerbate the risk of WNV emergence, persistence, and/or spillover in areas of high light pollution, which tend to occur in close proximity to human populations.
