With both the stationary and approaching radar experiments, we found some behavioral responses of cowbirds that could be associated with the presence of radar. In the stationary radar experiments, we found that birds moved more and decreased vigilance behaviors when exposed to radar, although other behaviors were not significantly affected. This did not follow our prediction that birds would decrease foraging and increase vigilance in response to radar. In the approaching radar experiment, we found that cowbirds responded earlier to approaches with the solid state (more powerful) radar, and diverged more from the path of the approaching vehicle with the magnetron radar (less powerful). This followed the predictions of our alternative hypothesis that radar increases alertness or attention to a threat