One of our local Downy Woodpeckers, a male, discovered our suet a few days ago. (Unfortunately, the local Starlings have discovered the suet, too, and are devastating it.) Today, the adult brought along one of its immature offspring and was feeding it suet. At first, the immature sat on the porch railing and the adult stuffed food into its mouth. Then the immature climbed onto the suet cage, and even though it was millimeters from the suet, it seemed to do little or no independent feeding while the adult continued to stuff suet into its mouth. I don't know how long this interaction continues in typical species with altricial young. I once watched two juncos frantically scurrying around to gather food to stuff into the mouth of a fledged cowbird they had been forced to adopt. Frank Gill (Ornithology) has quite a good discussion of the transition to independence in immature altricial birds as they develop skills of feeding themselves; he says the young of passerines remain with the adults for 2-3 weeks after fledging, but I don't find any information about what kinds of stimuli might signal adults to stop feeding. Perhaps the adults are continuing to respond to the releasing stimulus of the open mouth into which they've been stuffing food during the nestling phase, and as the young start to feed themselves, that mouth is no longer open in an "expectant" position. Does anyone know more experimental or observational information about this transition?

Burt Guttman
The Evergreen State College
Olympia, WA 98505 guttmanb at evergreen.edu
Home: 7334 Holmes Island Road S. E., Olympia, 98503


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