Meeting Abstract
Determining how an animal’s social context alters the expression of sickness behaviors (e.g. lethargy and anorexia) will help us understand how pathogens impact individual health and spread within groups. Although several studies have shown that animals can suppress sickness behaviors when housed in larger groups, few have examined whether individuals alter sickness behaviors based upon the infection status of other group members. Here we tested for differences in sickness behaviors during simulated bacterial infection in captive house sparrows under two housing treatments: 1) all of the flock inoculated (6/6 birds), or 2) only half of a flock inoculated (3/6 birds). Inoculated birds were treated with lipopolysaccharide (LPS), a nonreplicating component of gram-negative bacterial cell walls, to induce sickness behaviors. We monitored lethargy using automated radio telemetry. We predicted that LPS-inoculated birds housed with a mixture of inoculated and healthy flockmates would exhibit less-pronounced lethargy (i.e. suppressed sickness behaviors) than birds housed with only LPS-inoculated flockmates. Contrary to these predictions, we observed that inoculated birds showed similar levels of lethargy regardless of the infection status of their flockmates. These results suggest that house sparrows do not modulate sickness behaviors in response to social contexts comprised of equal numbers of healthy and inoculated birds. However, further experiments will be necessary to determine if house sparrows modulate their sickness behaviors when a higher proportion of the social group remains healthy.
