From south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] Thu Oct 31 10:34:56 2002 Received: from www.plaidworks.com (localhost [127.0.0.1]) by plaidworks.com (8.12.2/8.12.2) with ESMTP id g9VIWe7t008804 for <[[email protected]]>; Thu, 31 Oct 2002 10:32:40 -0800 (PST) Received: from rtjones.nas.nasa.gov (rtjones.nas.nasa.gov [129.99.19.30]) by plaidworks.com (8.12.2/8.12.2) with ESMTP id g9VIWHke008769 for <[[email protected]]>; Thu, 31 Oct 2002 10:32:17 -0800 (PST) Received: (from mrogers@localhost) by rtjones.nas.nasa.gov (SGI-8.9.3/8.9.3/NAS 8.9.3-5n) id KAA18592 for [[email protected]]; Thu, 31 Oct 2002 10:32:13 -0800 (PST) Date: Thu, 31 Oct 2002 10:32:13 -0800 (PST) From: "Dr. Michael M. Rogers" <[[email protected]]> Message-Id: <[[email protected]]> Subject: [SBB] more on the YHBL X-BeenThere: [[email protected]] X-Mailman-Version: 2.1b4+ Precedence: list Cc: South Bay Birding <[[email protected]]> List-Unsubscribe: , List-Id: South Bay Birding List-Post: List-Help: List-Subscribe: , To: [[email protected]] Sender: south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] Errors-To: south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] All, Wondering about the small size of the Calero stables Yellow-headed Blackbird, I dug out the bible, Pyle's Identification Guide to North American Birds. I was surprised to see that hatching-year female Yellow-headed Blackbirds (but not adult females) also show white tipped primary coverts (figure 327), although typically the pale tips are narrower. The tips on the Calero bird were extremely narrow and did not extend along the leading edge as shown in Sibley for the first-winter male (although Pyle doesn't show this for hatching-year males either). Male Yellow-headed Blackbirds do get larger with age, but given the Calero bird's size and the very limited white on the primary coverts I think it is likely a first-winter female rather than a first-winter male. Pyle gives the following wing and tail measurements (in millimeters): YELLOW-HEADED BLACKBIRD wing chord tail length first-winter female 105-119 72-83 adult female 110-125 77-90 first-winter male 126-137 88-104 adult male 135-150 96-112 TRICOLORED BLACKBIRD female 101-112 71-81 male 115-127 83-94 The Yellow-headed Blackbird seemed very similar in size to the male Tricolored Blackbirds, perhaps even smaller than the biggest males, which would suggest a female or a very small male Yellow-headed Blackbird. Yellow-headed Blackbirds formerly (a hundred years ago) bred in marshes south of San Jose; these marshes no longer exist, and the bird is now only a migrant in the county. Despite overwintering in the nearby Central Valley, we have virtually no evidence of any wintering birds in Santa Clara County. We have numerous (about 50) records of spring migrants spanning 28 March (1969!) to 26 May (1972), with most falling between mid-April and mid-May. The bird is less common as a fall migrant, with about a dozen records between 5 August and 5 October, with half of these falling between 13 and 20 September. Oddball records include an old one from 14 Jul 1955, two more recent records from 7 June 1999 (pair at Gilroy sewer ponds - attempting to nest??!) and 22 July 1999 (adult male at the Palo Alto Baylands duck pond). The only winter record is of a male at Milpitas High School on 13 January 1988. Thus our currrent record from 27-29+ October 2002 is quite significant, being three weeks later than our previous late fall bird. Will it attempt to winter? Mike Rogers _______________________________________________ Do not post admin requests to the list. They will be ignored. south-bay-birds mailing list ([[email protected]]) Help/Unsubscribe/Update your Subscription: http://www.plaidworks.com/mailman/options/south-bay-birds/south-bay-birds-archive%40plaidworks.com This email sent to [[email protected]]