This morning in McCrillis Garden on Greentree Road in Bethesda, Bill and I were startled (and dismayed) to see a Carolina Wren feeding a juvenile Brown-headed Cowbird.  According to the MD-DC Breeding Bird Atlas (1993), the Carolina Wren "is a very rare victim of Brown-headed Cowbird parasitism.... There are no records from Maryland and few known instances of Carolina Wrens successfully fledging young cowbirds...."  

Jane Hill
Bethesda, MD