Date: Mon, 7 Jul 2003 10:20:53 -0400 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Marcia Watson-Whitmyre Subject: Robins - nest parasitism? I'm posting the message below at the request of Nick Pulcinella from West Chester, who is covering a couple of Cecil Atlas blocks along the MD-PA line. Nick is seeking input on baby robins in other species' nests. I hope someone out there has some insight into this. Marcia Watson-Whitmyre Cecil County ************************** Hi MD Birders, I had a strange Atlas experience a few weeks ago that still has me perplexed. While working one of our blocks in northeast Cecil Co. 6/15 we watched a female Yellow Warbler carry food into a tree. While watching, we saw the bird go to the nest and feed what we thought was a young cowbird. Approaching the nest to get a better view, we noticed that the large baby bird was not a cowbird, but a robin. We watched longer to make sure of our finding. The yellow warbler parents came in several times and each time fed the baby robin. The robin seemed to take up the entire nest space. To add more confusion, while watching the robin, I saw what appeared to be movement in the nest behind the robin. At that point a baby yellow warbler walked up onto the back and then the head of the robin and out onto a tree limb. From then on when the yellow warbler parents came in with food, they found the baby yellow warbler on the nearby limb and fed it instead of the robin. I'm kind of stumped as to why the robin was in the nest. I've tried to think of a scenario that would put the robin in the nest. I thought that maybe it was originally a robin nest which contained a robin egg which was then abandoned and then the nest used by the yellow warbler which hatched both eggs. The problem to me with that theory is that the nest appeared to be typical of other yellow warbler nests I have seen. I've been unable to find anything in the literature about "robin parasitism". I'd be interested in any other thoughts. Thanks in advance. Nick Pulcinella West Chester, PA ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================