Two intergeneric hybrids between motmots from the Amazon forest: Rufous Motmot (Baryphthengus martii) × Amazonian Motmot (Momotus momota)

Abstract

Hybridization is a relatively common phenomenon in birds, but it is probably underestimated due to our poor knowledge on the reproductive biology of several species. Here, we present the second case of intergeneric hybrid in the family Momotidae and the first case between Amazonian Motmot (Momotus momota) and Rufous Motmot (Baryphthengus martii). In addition to the field record documented herein, we searched for possible hybrids among 57 study skins and 175 photographs and videos publicly available in online databases. The overall plumage pattern of the hybrid individual recorded in the field was similar to that of the Rufous Motmot, except for the following features, which appear to have been inherited from the Amazonian Motmot: two narrow blue lines in the facial mask; distinct blue feathers on the pectoral spot; and central rectrices with terminal racquets. Among the database photos examined, we found a second possible hybrid, with the same diagnostic features present in the hybrid recorded in the field. Similarities in behavior and vocalizations, in addition to the scarcity of mates in the limits of the distributions of Amazonian and Rufous Motmots, may explain the occurrence of hybrids between them.