From south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] Wed Jun 4 11:25:46 2003 Received: from www.plaidworks.com (localhost [127.0.0.1]) by plaidworks.com (8.12.9/8.12.9) with ESMTP id h54INFa9016285 for <[[email protected]]>; Wed, 4 Jun 2003 11:23:15 -0700 (PDT) Received: from mail07b.vwh1.net (mail07b.vwh1.net [207.201.152.67]) by plaidworks.com (8.12.9/8.12.9) with SMTP id h54ILtfF016238 for <[[email protected]]>; Wed, 4 Jun 2003 11:21:55 -0700 (PDT) Received: from www.hiddenvilla.org (209.238.206.251) by mail07b.vwh1.net (RS ver 1.0.80vs) with SMTP id 1-037299906 for <[[email protected]]>; Wed, 4 Jun 2003 14:21:47 -0400 (EDT) Message-ID: <001201c32ac5$e8bb0380$[[email protected]]> From: "Garth Harwood" <[[email protected]]> To: "SBB" <[[email protected]]> Date: Wed, 4 Jun 2003 11:19:58 -0700 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 X-Loop-Detect: 1 Content-Type: text/plain; charset="iso-8859-1" X-Content-Filtered-By: Mailman/MimeDel 2.1.2+ Subject: [SBB] Nestboxes, uncommon birds, and an Acorn Woodpecker mystery X-BeenThere: [[email protected]] X-Mailman-Version: 2.1.2+ Precedence: list List-Id: South Bay Birding List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] Errors-To: south-bay-birds-bounces+south-bay-birds-archive=[[email protected]] Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by plaidworks.com id h54INFa9016285 Today (6/4/2003) while checking nestboxes at Byrne Preserve, a CHIPPING SPARROW was singing for the better part of an hour from the two large Valley Oaks atop the hill next to Altamont Road. I watched for 10 minutes but could not verify any breeding behavior (or even a mate). A WESTERN WOOD-PEWEE, also singing in that immediate area, was only the second I've encountered this season in my north/west county haunts (the first was last week at Arastradero Preserve.) Monday June 2 I had a single flyover LAWRENCE'S GOLDFINCH pass over Arastradero toward Felt Lake, northbound. There is still a singing male WESTERN TANAGER at Hidden Villa, typically found in streamside trees between the Duveneck House and Education Center. No breeding confirmation yet. Three sets of WESTERN BLUEBIRDS fledged this week from the 8 boxes I maintain at Byrne, although numbers of surviving young are about half last year's total. Family groups were still in the vicinity of each box during today's visit. An ASH-THROATED FLYCATCHER was incubating 4 eggs. Looks like a pretty decent nesting year for that species in an otherwise-pathetic nestbox season; I also have ATFL incubating clutches at Hidden Villa, Arastradero (2), and Foothills Park (2), without any losses such as those afflicting all other species. A good strategy to be a late-starter this year, I guess. No VIOLET-GREEN SWALLOWS have settled into my boxes at Byrne this season, but one pair is using a tree cavity and another is in a two-hole nestbox someone else put in up there, which does not open for monitoring or cleanout. There are a few VGSW nests active in my boxes elsewhere, but less than half of the typical number; I fear this species has taken the weather hard this season. Two of the Byrne nestboxes have partial stick nests resembling those of HOUSE WREN, but without inner linings or eggs. Dummy nests, no doubt. One HOWR was singing here on May 21 near a big oak snag in the middle of the preserve. May also have one at Arastradero, but if so it is uncommonly secretive. For the first time ever, I had an ACORN WOODPECKER initiate nesting in one of my boxes, along the eastern border of Arastradero overlooking Hwy 280. I say "initiate", because an ACWO was sitting on 3 large white eggs on 5/24, but when I checked on 6/2 there was no sign of bird or eggs (there never was any nest material, just an excavated indentation in the wood floor). If, as I suspect, the bird simply carried her eggs to a different location where no large bipeds seem likely to intrude, it would explain a lot of things from that area over the years. Specifically, over the past several years, all or portions of nests and eggs of ATFL, WEBL, HOWR, and VGSW have disappeared from that corner of the preserve. During all of that time, there has been persistent evidence of woodpecker interest in the boxes there, but I had never made the connection before. This week the evidence of possible ACWO nest predation is especially compelling because of the removal of their own eggs AND the loss of a complete swallow nest (again, nest and all) two boxes over which had contained at least 2 eggs. And sure enough, the entry to the latter box has been enlarged and the floor excavated. Anyone know of research into interspecific nest predation by Acorn Woodpeckers? I have heard of woodpeckers interrupting each other's efforts, but not this kind of generalized activity. (Incidentally, I rule out other more common predators because I have "seen it all" out there by now - each has its telltale signs. Human intervention seems very unlikely given the obscurity of these off-trail locations and inaccessibility; some are mounted as much as 16' high.) --Garth Harwood _______________________________________________ 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]]