Parent-offspring conflict in blue-throated hummingbirds

摘要

The more than 300 species of hummingbirds exhibit considerable morphological and ecological diversity. Some aspects of reproductive behavior vary among species, but other behavior is more uniform. As far as is known, hummingbirds are polygynous, with only rare reports of males participating in parental care (Johnsgard, 1997). Males therefore are not generally thought to have much if any interaction with nestlings or fledglings. Here I report a previously undocumented aspect of hummingbird behavior: aggression toward nestlings and fledglings by both males and females in blue-throated hmmningbirds (Lampornis clemenciae). In blue-throated hummingbirds, the sexes have non-overlapping territories during the breeding season, but during a brief courtship period, they associate in the same area for several days before separating (Wagner, 1952; M. S. Ficken, pers. obser.). The species is multibrooded (Brandt, 1951; Wagner, 1952; Williamson, 2000) and some nests fail. As sexual interactions may occur for several days before each nesting (Wagner, 1952; M. S. Ficken, pets. obser.), males and females may be in proximity when fledglings are also present.