Mixed-species aggregations in birds: zenaida doves, Zenaida aurita, respond to the alarm calls of carib grackles, Quiscalus lugubris

Aggregating with heterospecifics may be particularly beneficial for a species that is able to exploit the antipredator behaviour of another. Territorial zenaida doves vigorously exclude conspecific intruders from their territory, but forage with, and acquire novel foraging techniques from, carib grackles. Given that doves associate with no other conspecific than their mate and they have no vocal alarm signals of their own, they might benefit from attending to the conspicuous alarm calls of carib grackles. In the present study, we found that zenaida doves suppressed foraging both in response to a model predator and in response to the sound of grackle alarm vocalizations. Although doves' responses to the predator model also involved moving away from the immediate vicinity, their responses to grackle alarm vocalizations consisted of remaining alert and tail flicking. Together, these results strongly suggest that doves attend to the antipredator behaviour of carib grackles. These findings extend earlier work demonstrating that doves obtain foraging benefits from their association with grackles, to show that they may also obtain predator avoidance benefits.