Folks:
For what it's worth, here are extracts from the 1980s:
BLACK-BILLED MAGPIE (BBMA)
15 Jan-11 Mar 1984
“The status of a Black-billed Magpie in
residential Concord, Contra Costa Jan. 15-Mar. 11
(†JRi et al.) was certainly questionable, but the
possibility that this unworn individual arrived
on its own cannot be ruled out.” (Am. Birds
38:354) [Jean Richmond. Regional record.]
1 Dec 1987+
“A Black-billed Magpie near Blue Lake, Humboldt
(fide C. Ogan, no date), was dismissed by GSL as
an escapee; no specific evidence for captivity
was given, and I suspect that in general most
extralimital magpie records are not of escapees.”
(Am. Birds 42:317) [C. Ogan, Gary S. Lester. Regional record.]
21 Mar 1989
“Two Black-billed Magpies near Coyote, Santa
Clara, Mar. 21 (†J. Glass) were
problematic. Birds as far south as Contra Costa
have been considered part of a pattern of genuine
vagrants, in n.w. California primarily and in
fall/winter almost exclusively. The species is
common in captivity, however, and numerous other
records throughout the state have been dismissed
as escapees. Two birds this far south, out of
season, and so close to a major urban area are
best added to the latter group.” (Am. Birds 43:533) [Jane Glass.]
Bill Bousman
Menlo Park
At 08:26 PM 12/14/2010, Bruce Webb wrote:
>
>
>I recall a discussion in American Birds years ago, or perhaps as far
>back as Audubon Field Notes, by Tim Manolis of a report of a
>Black-billed Magpie reaching the western Sierra. I cannot recall in
>which county it was seen, but it was south of PLA. Tim will no doubt
>chime in when he (ever) gets back through the snow from the Susanville CBC.
>
>Occam's Razor and proximity to South Lake Tahoe would support the
>rationale of a Black-billed Magpie rather than a Yellow-billed appearing
>with selective soft part melanism. The Hwy 50 corridor seems conducive
>to allowing one of the common South Lake Tahoe magpies to reach the west
>slope of El Dorado county.
>
>Several species of corvids in the neotropics have yellow bills as
>juveniles that darken when adults. Someone with more knowledge of the
>literature can hopefully comment whether soft part hyper-melanism occurs
>in wild birds.
>
>Bruce Webb
>Granite Bay, CA
>
>On 12/14/2010 6:28 PM, ERPFROMCA@... wrote:
> >
> > I have just uploaded to CVBirds and CALBIRDS a photo taken late last
> > month
> > near Pilot Hill, western El Dorado County (elev 800 ft) of what
> > appears to
> > be a Black-billed Magpie with Yellow-billed Magpies. (photo by Terry
> > Armstrong
> (_http://imagesbysydney.com_
> (http://imagesbysydney.com) )).
> >
> > Chris Conard first brought this photo to our attention. The photo is
> > on the
> > CVBirds Yahoogroups page in the 'Crows, etc' folder and in the CALBIRDS
> > page in the 'Mystery Birds' folder.
> >
> > This would be, as far we can determine, the first documented (by specimen
> > or photo) Black-billed Magpie ever found on the west side of the Sierra
> > Range. The mystery is that, from this photo, the bird appears to be
> > the same
> > size as the Yellow-billed Magpies nearby. Of course, determining size
> > from
> > photos can be VERY tricky if the birds are not right next to each
> > other. The
> > bird with the black bill is behind the Yellow-billed Magpie, but how far
> > behind Jeff Davis has suggested that this may be a Yellow-billed
> > Magpie with
> > a pigment abnormality (e.g. hypermelanism of the soft parts). On the
> > other
> > hand, in Sibley's Guide to Birds he suggests that southern Black-billed
> > Magpies are smaller than their northern counterparts, though he cites no
> > source to support this.
> >
> > So I put two questions to the group.
> >
> > 1. Has anyone ever seen or have reliable info about Yellow-billed Magpies
> > exhibiting a pigment abnormality like this Since many thousands of
> > magpies
> > were collected during the West Nile Virus outbreak of a few summers ago,
> > perhaps such a specimen was seen
> >
> > 2. Does anyone know of evidence for Black-billed Magpies being smaller in
> > the south, and if so, how small can they be Can they approach the
> > size of a
> > Yellow-billed Magpie
> >
> > It might be best to send me your replies off line and I can summarize for
> > the group later.
> >
> >
> > Ed Pandolfino
> > Carmichael, CA
> >
> > |