Age-Related Tick Infestation Patterns in Springtime Migratory Passerines

To test the hypothesis that younger migrants are more prone to arrive at stopover sites on the northern coast of the Gulf of Mexico with ticks than adult migrants, 2177 migratory passerines were screened for ticks at Gulf Coast sites in Texas and Louisiana. Fifty eight (2.7%) were infested with ticks with 28 (1.3%) being young birds and 30 (1.4%) being adult birds. The body condition of the birds was assessed to determine if tick infestation had negative consequences and if the severity of consequences varied between ages. I found no relationship of age with the prevalence of a tick attachment in any of the groups of birds. I also did not detect any consequences on body condition due to tick infestation, with the exception of the warbler group for which mean body mass was significantly lower in tick infested birds. Tick infestation does not seem to vary in young and old migrant birds and infestation alone does not seem to pose a major physiological cost to most migratory passerines