Re: Red Crossbills in May?

Bill Bousman

Dear Lee and others,

I wrote a paper in Western Birds in 2007 that compared recent atlas and other sources in the nine San Francisco Bay area counties with Grinnell and Wythe's summary through the late 1920s.  In that effort, I looked for the earliest records I could find in the Bay area.  I never found any records for Sonoma.  The earliest record I found for Marin was of a bird gathering nest material in 1960 on Inverness Ridge, Marin County; for San Francisco, an adult was feeding young in Lincoln Park in 1974; and fledged young were seen along Gazos Creek Road in July 1984.  I never found any records for Alameda or Contra Costa counties.

The San Mateo atlas confirmed breeding in six blocks over the period 1991-97.  An atlas was conducted in Santa Cruz County (not treated in my paper), but not published.  David Suddjian told me that they found some breeding in the coastal coniferous forests.  We had probable breeding  birds along the Santa Cruz Mountain crest as reported in the Santa Clara atlas.

The species is known to breed within its normal range at any time of the year when there is a good supply of cones for that particular type crossbill.  Invasion years would seem to make such nesting more likely.  It certainly remains a bird of mystery.

Bill Bousman
Menlo Park

On 5/8/2020 3:12 PM, Lee Friedman wrote:
Yesterday I saw and photographed a pair of Red Crossbills on restricted EBMUD land (no trail access, sorry) in the conifers on the east side of the San Pablo Reservoir. The pair, one male and the other female, seemed to stay near each other. I checked in the Breeding Bird atlases for Contra Costa and for Alameda; neither included Red Crossbills as breeders for this area. The Alameda atlas mentioned a few records of breeding in Hayward from over 100 years ago, and said the species breeds along the northern California coast only down to Sonoma County, and also in the Sierra Nevada. There also don’t appear to be any May sightings of Red Crossbills in eBird records for Contra Costa (although Steve Buffi reported one on 4/24 of this year, and Jerald Britten reported 5 in Clayton on 4/30). I’m wondering if the pair I saw could possibly be breeding here this year? Red Crossbills are prone to irruptions and this year there have been more of them around than usual (there have also been a number of recent sightings of them in San Francisco). Anyone know about the chances that some might stay and breed in the East Bay?

Checklist with photos for id purposes:

Good birding,
Lee Friedman

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