Parental care of fledgling Wood Thrushes

We report the study of parental care of Wood Thrush (Hylocichla mustelina) fledglings from nest-leaving to independence. From 1993 to 1995, we capture d, radio-tagged, and monitored the movements and behavior of 23 fledglings and their parents from 12 broods at the U.S. Marine Corps Base, Quantico, V irginia. For pairs that subsequently renested (n = 5), the family group of male, female, and fledglings, remained within 62 (+/-5 SE) m of the first n est after fledging, During the period of post-fledging parental care, mean maximum distance between parents was 70 (+/-14) m. Females attended the you ng 13 (+/-1.3) days before initiating the incubation of a second clutch. Ma les continued attending the fledglings for 6 (+/-0.7) more days until the y oung achieved independence and dispersed (28-36 days post-hatching). In fin al clutches (n = 73, brood care was divided between the parents, and the po sition of the fledglings relative to the nest depended on the parents' choi ce of molting site tin the nesting area or elsewhere). Division of the broo d by the parents has been thought to be a strategy to reduce predation and increase foraging efficiency. However, in the Wood Thrush and other species , joint attendance of initial broods, but division of final broods, suggest that other factors could be important for the parents' decision of whether or not to split the brood.