If you prowl around the desert's wetlands, you may be privileged to see a female duck with five or six ducklings trailing behind, almost as if tethered to momma. You may be tempted to think, "Oh, isn't it amazing that baby birds right out of the egg instinctively recognize their mother!"
As it happens, though, the tie between mother and offspring doesn't quite work that way. A number of birds that become active right after hatching depend on imprinting. That means they become attracted to the first large moving object they see. Usually, of course, this is going to be the mother--but that's not always the case. One of the first behaviorists to recognize what was going on had it impressed upon him when, for all practical purposes, he became Mom to a brood of incubator-hatched geese.
As far as imprinted birds are concerned, that first moving object IS Mom, and the real mother may be completely ignored. Just imagine the chagrin of baby birds, though, if Mom turns out to be a car taking off without them!
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
Gadwall female with trailing brood. Photograph courtesy of the U.S. Fish and Wildlife Service.