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Much like the stories of babies being delivered from the sky to the bassinet by a stork, the accounts of young birds being carried from elevated tree nests to the ground in the bill of their mother appear to be fairy tales -- or, at best, descriptions of very atypical behavior. Reports of chicks jumping to the ground rather than being carried from the nest by a parent are far more common. Aerial carrying has been reported in 16 species of seven waterfowl groups as well as Virginia and Clapper Rails, gallinules, willets, woodcocks, chachalacas, and a cuckoo. Nevertheless, ornithologists remain uncertain of both the conditions leading to it and how it is accomplished. Making observations is difficult, given that aerial transport occurs either discreetly under the cover of dim light or in panic situations when a parent is confronted by a predator. Thus, most information remains anecdotal. It is not clear, for example, whether a parent holds its chick in its bill, carries it on its back, or clutches it between its legs. In addition to aerial carrying there are also a few reports of birds using their wings to clap chicks to their sides and proceeding on foot.
Much more is known about birds that carry their young while swimming. Worldwide, three species of swan, at least seven species of duck, and various other birds of the wetlands have been frequently observed chauffeuring their young as the accompanying American Coot illustration shows. In all cases, the young initiate the ride and are readily able to hang on by clamping their bills over the feathers of the adult should it decide to dive. Ferrying by adults over water is apparently most advantageous in species that fly infrequently, that have large bodies and small broods, and whose young grow slowly. Careful observations are needed to document how frequently and under what circumstances parent birds carry their young. But birders fortunate enough to witness parental transport should be cautious: some species feign carrying their young. The Eurasian (and perhaps American) Woodcock uses this type of distraction display to lure predators away from its chicks. Such displays may effectively fool predators and foil their attempts to locate young. Birders with pencil in hand need to be careful that they, too, don't fall for this ruse. SEE: Parental Care; Distraction Displays; Precocial and Altricial Young. Copyright ® 1988 by Paul R. Ehrlich, David S. Dobkin, and Darryl Wheye. |
