Triple Brooding by Southern Ontario Wood Thrushes

摘要

Wood Thrushes (Hylochla muste- lina) typically are double brooded, and triple brooding is rare, even in the southern portions of their breeding range. We discovered one instance of triple brooding by a pair of Wood Thrushes in southern Ontario near the northern edge of their continental breeding range. Each of the three nesting attempts successfully fledged Young. Females may spend only a short time (less than A week) with just-fledged broods before initiating an- Other nest; in this circumstance, the survival of young Birds from the earlier brood depend son the attentive- Ness of males. The rearing of three broods is an un- Common event among Wood Thrushes in our study; Form 1998-2000, only one of 73 color-banded females (1.3/100) with early season nesting success has been tri- ple brooded.