Date: Wed, 30 Apr 2003 12:43:50 -0400 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Pete Webb Subject: Chestnut-sided Warbler, two YCNH nests here MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Heard a CHESTNUT-SIDED WARBLER singing in my back yard this morning; didn't see any posted yet on MDOSPREY. The bird might have been heard in the distance yesterday; it was too far & faint at the time to ID. In other news, while I * STILL * haven't seen any incubating, the tree with my YELLOW-CROWNED NIGHT-HERONS hosted FIVE adults yesterday: the two standing at the established nest, another bird in a branch above them, and two more starting to build ANOTHER nest in another branch on the opposite side of the same large, spreading oak tree! A neighbor reports still another active nest just a few houses away next to the Gwynns Falls stream where the birds all go crayfishing (the established nesting pair goes to another stretch of the stream for theirs, not the portion near the reported other nest). It looks like we might have a little colony starting to form here. In the past, all the nesting pairs I knew of in my area seemed to have solitary nests well spread out among the neighborhoods along the stream. I also took the time to peruse my Bent reference book and found that at the time the book was written, YCNH's seemed to be known only from larger swamps in the South; the populations along upland crayfish streams in the Piedmont escaped mention. Also, I found no description of the third-year plumage; Bent seemed to leave the reader with the assumption that birds beyond second-year plumage would all be in indistinguishable full adult plumage. In my experience, third-year birds (which were raised two summers ago) have near-adult plumage distinguishable from full adult (fourth-year and older) plumage in being more of a brownish-gray in color, easily distinguishable when a full adult is standing nearby with its more blue-gray color. Also, in breeding (alternate) plumage, the third-year bird has fewer plumes on its back and crown. The yellow forehead appears identical with the full adult plumage. In fact, while third-year birds can be easily identified when standing next to a full adult, they aren't easily distinguished without the contrasting full adult bird standing nearby for comparison. Second-year plumage, not shown in most field guides, is a more gray-brown (much browner than the 3rd year birds) with the head patterns muted in shades of gray-brown rather than black and white, somewhat like the tan-stripe White-throated Sparrows versus the white-stripe White-throats. Second-year birds I've seen lack the yellow forehead of breeding plumage third-year and adult birds. I don't remember seeing any breeding plumes standing out from the back or crown. As for third-year color and sexual dimorphism, I've seen indistinguishable adults (I couldn't tell which was which by color, although my wife believed the yellow forehead may have been brighter on the male) which were at the time our established breeding pair contrasting with a third-year bird which they had raised two summers ago which wanted to hang around with the family group as it had the previous summer as a second-year bird. In the current situation, the pair at the established nest is one blue and one brown (3rd-year bird, female when they copulated) and the second couple building the new nest are both blue (full adult). The fifth bird hanging out above the "established" couple was also a blue. Pete Webb Baltimore County, MD home (after 7 weekdays) pwebb~at~bcpl.net work (M-F 830-5) pew~at~niroinc.com ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================