Kleptoparasitism and territoriality in the Snail Kite Rostrhamus sociabilis (Accipitriformes: Accipitridae) in the Complejo Güija, El Salvador

Abstract

We present the observations of some kleptoparasitic and territorial interactions in the Snail Kite (Rostrhamus sociabilis), following focal individuals from January to May 2017 in two wetlands of El Salvador. Those interactions were performed during their food searching and managing of prey on perch. We observed two attempts of kleptoparasitism from Great-tailed Grackle (Quiscalus mexicanus) to R. sociabilis. On the first case, a flock of Q. mexicanus chased an adult Snail Kite, which had captured a snail; on the second case, a male of Q. mexicanus tried to steal a young Snail Kite's prey, which was managing its prey on perch. On both cases in response to the attack, two individuals chose to change perch to complete the consumption of its prey. We also observed an intent of kleptoparasitism between two male Snail Kites, after the attack, on perch the chased bird released the snail and moved to another site, meanwhile, the attacker ended up eating the snail. We attribute this observation to a kleptoparasitic behavior, related to water stress and variations in prey availability. We recorded Snail Kite's territorial behavior between the species and against other raptors, as a way to protect their feeding territories. With these observations, we provide some information about the ecological behavior of the species in El Salvador. We stress the need to carry out research related to the interaction between R. sociabilis and Q. mexicanus on its feeding sites, focusing in the eff ect of water scarcity and snail availability on the behavior of the Snail Kite.