4.1 Northern
Goshawk, South Lake Merced, City of San Francisco
Today, I birder South Lake Merced
and was shocked to encounter an adult NORTHERN GOSHAWK west of
the west end of the concrete bridge at the Vista Grande Canal.
Original voice notes from the parking lot can be found here.
Description:
I was approaching the Vista Grande Canal west of the west end
of the concrete bridge at South Lake Merced when a very large,
"cold" accipiter or accipiter-like bird exploded out
of one the mature trees along the canal. Structurally, the bird
was very accipiter-like; the tail was very long and the wings
were relatively fat. I immediately got my bins on the bird, not
50 feet away from me in superb front-light and was shocked to
observe fine gray vermiculations along the entire underparts
of the body of the bird as it flew by me. Well aware of the significance
of this field mark, I attempted to find additional field marks
on the bird.
The head of the bird had dark on the upper half, which I initially thought was an eyeline. My voice notes are equivocal on this, but based on some soul-searching and the fact that I had a dominantly ventral view of the bird when I noticed this field mark, I do believe that this was a dark eye line. Supporting evidence for this thesis is that no part of the supercilium nor cap of the bird was observed. I had a great look at the torso of the bird, it reminded me of an overstuffed sausage casing; a very powerful, stocky bird unlike a typical accipiter body shape. The tail of the bird had at least four and possibly five bands on the tail, roughly equally space light and dark. The banding on the belly mentioned above continued all the way to the undertail coverts that strongly contrasting fluffy white.
The bird briefly dipped out of sight behind a tree and I refound it when it briefly terrorized the Rock Pigeon flock on the power poles at the west end of the concrete bridge. During this mayhem, the bird provided a good size comparison and dwarfed the Rock Pigeons comparatively. As the bird left the pigeon flock and flew to the south, I got fair dorsal views of the bird. While I can provide little detail of the upperparts, the banding on the uppertail did leave the impression of being irregular (not aligned) across the rectrices. The bird continued most of the way to the south end of the lake and then disappeared into the trees east of the east side of the lake.
Analysis:
My initial impression was "Jeez; this is a Goshawk!"
immediately followed by "I must have made a mistake."
Try as I may, it is very hard to turn this observation into something
more expected. No vulture nor condor has white underparts of
any sort. Adult male Northern Harrier has prominent black markings
on the underwing and vertical barring on the breast. Osprey has
pale underparts and a dark eye line, but lacks any sort of vermiculations
on the underparts and would be unlikely to chase pigeons. Juvenile
Hook-billed Kite has pale underparts with fine dark barring on
the chest and a barred tailed but is unrecorded in CA. White-tailed
Kite has clean white underparts and underwings with a black carpal
patch on the underwing. Mississippi Kite lacks gray vermiculations
in any plumage.
Adult Gray Hawk requires some discussion. Gray Hawk is a "cold" bird much as this bird, with fine gray horizontal vermiculations on the body and white undertail coverts. However, the wing shape is distinctly pinched at the body and the proportions are definitely more "buteo-like" with the tail being not disproportionately long. Also, it has a plain gray face and lacks any dark on the head and I have recent field experience with Gray Hawk from Mexico. Red-shouldered Hawk shows distinctly red plumage on underparts and underwings and lacks dark on the head. Adult Broad-winged Hawk has barring merging into reddish-brown bib and distinctly-patterned strongly outlined wing; lacks long tail. No other buteo or eagle shows vermiculations on the underparts such as this bird.
Of the falcons, Peregrine Falcon has barred underparts, but lacks white undertail coverts and adults have a strongly-patterned hood on the head. Finally, we're left with accipiters. All juvenile accipiters are eliminated by the horizontal barring. Both adult Cooper's Hawk and Sharp-shinned Hawk can be eliminated by coarse red barring on the underparts. Only adult NORTHERN GOSHAWK has fine gray vermiculations with contrasting fluffy white undertail coverts. The dark eyeline and irregular barring on the uppertail further support the identification.
Northern Goshawk is of course completely unexpected in San Francisco with but 3 previous records all in the fall. An adult bird would seem to be even less likely. Birds of Northern California suggest that the first week in April is the end of the winter tenure for the species in Northern CA, perhaps suggesting that this bird was returning north during my all too fortunate observation.
4.3 Correction: Status of Northern Goshawk
in SF
Hugh Cotter kindly pointed out that
Northern Goshawk is a casual annual fall transient with 1-2 records
a year based on the records from GGRO and that many of the birds
[seen from Hawk Hill] head across into San Francisco.
4.6 [SFBirds] Lake Merced
Not much to add from south lake today
other than a pair of GREATER SCAUP and a dazzling drake CINNAMON
TEAL. All YELLOW-RUMPED WARBLERS save one that I identifed were
Myrtle Warblers. A RED-WINGED BLACKBIRD posed nicely at the edge
of the concrete bridge, ©2006, Mark W. Eaton:
4.8 [SFBirds] Lake Merced
South Lake Merced had a breeding-plumage
EARED GREBE and I had about 25 BAND-TAILED PIGEONS flying over.
At North Lake Merced, PURPLE FINCHES were singing along with
AMERICAN GOLDFINCHES and there were at least 2-3 SPOTTED TOWHEES
as well. I ran into Calvin and Michelle and Michelle pointed
out a WHITE-THROATED SWIFT.
4.9-12 Morongo Canyon Preserve and Joshua
Tree NP
Mallard
Gambel's Quail
Great Egret
Turkey Vulture
Cooper's Hawk
Red-shouldered Hawk
Red-tailed Hawk
American Kestrel
Prairie Falcon
Sora
American Coot
Rock Pigeon
Mourning Dove
Lesser Nighthawk
Vaux's Swift
White-throated Swift
Anna's Hummingbird
Costa's Hummingbird
Ladder-backed Woodpecker
Nuttall's Woodpecker
Pacific-slope Flycatcher
Black Phoebe
Say's Phoebe
Vermilion Flycatcher
Ash-throated Flycatcher
Western Kingbird
Loggerhead Shrike
Plumbeous Vireo
Hutton's Vireo
Western Scrub-Jay
American Crow
Common Raven
Violet-green Swallow
Cliff Swallow
Barn Swallow
Mountain Chickadee
Verdin
Bushtit
Cactus Wren
Rock Wren
Canyon Wren
Bewick's Wren
House Wren
Ruby-crowned Kinglet
Western Bluebird
Hermit Thrush
Northern Mockingbird
California Thrasher
European Starling
Phainopepla
Orange-crowned Warbler
Nashville Warbler
Yellow-rumped Warbler
Black-throated Gray Warbler
Common Yellowthroat
Western Tanager
Spotted Towhee
Chipping Sparrow
Brewer's Sparrow
Black-throated Sparrow
Song Sparrow
Lincoln's Sparrow
White-crowned Sparrow
Black-headed Grosbeak
Red-winged Blackbird
Western Meadowlark
Brewer's Blackbird
Hooded Oriole
Bullock's Oriole
House Finch
Lesser Goldfinch
Lawrence's Goldfinch
House Sparrow
4.15 [SFBirds] Lake Merced
Not much evidence of migration, but
I had a few unusual things. First was a swallow at the the boathouse
that, in binoculars, appeared to have an entirely white rump.
I assumed I wasn't picking up enough detail, but another VIOLET-GREEN
SWALLOW flew into the same field of view and I could clearly
see the band between the two white rump patches on those individuals.
Subsquently, I relocated the bird in my scope and could just
discern a fine dark band inbetween the two rump patches. Compared
to other VGSWs, the width of this band was less than 1/3 of the
width of what the rest of the birds were like. If this is normal
variation, it's certainly new to me. The face pattern appeared
to be typical of VGSW.
At North Lake Merced, a COMMON YELLOWTHROAT was singing a song quite a bit different from the standard COYE song and both VIRGINIA RAIL and SORA were spontaneously vocalizing during a break in the showers. A pair of male WILSON'S WARBLERs and a TOWNSEND'S WARBLER were together, possibly on the move. PURPLE FINCHES and AMERICAN GOLDFINCHES are present in good numbers.
4.16 [SFBirds]
Pileated Woodpecker
I got a phone call from Hugh Cotter
indicating that Michelle had found a PILEATED WOODPECKER on Bayview
Hill. I immediately packed up and headed up there. Upon arriving,
I located Hugh, Alan, Calvin and Eric that had just refound the
bird. I was fortunate to get the record shots below of this first
city record. Amazing!
All photos ©2006, Mark W. Eaton.
4.22 Chain of Lakes
Only a few things of interest this
afternoon at the Chain of Lakes. Middle Lake had a HUTTON'S VIREO
that is possibly breeding. I tracked it to a dense tangle above
the glen and there were some interesting sounds coming from an
unseen location therein. A nest could easily be in there. There
was also an ORANGE-CROWNED WARBLER in the gleaner flock. At the
north end, there were roughly 50 CEDAR WAXWINGs and a STELLER'S
JAY was also in the area. North Lake had a juvenile BLACK-CROWNED
NIGHT HERON that was pointed out to me and the Buffalo Paddock
had a COYOTE.
4.30 Lobos Dunes - Western Bluebirds, Calliope
Hummingbird
Both the male and female WESTERN BLUEBIRDs
were around if hard to find in the area. I didn't actually see
them go in or out of a nest hole, but given their prolonged absence,
it seems like they might incubating. Also, I had a female-type
CALLIOPE HUMMINGBIRD in the on the fence at the east edge of
the maintenance yard. It was a noticeably small green and white
hummingbird, had a very short, thin bill, fine stippling on the
the throat and a buffy/salmon wash along the lower flanks. I
tried to get close enough for photos, but I had to cross into
the restoration area (nothing but ice plant and rye grass here...)
and couldn't relocate the bird in the evergreens. However, there
were several hummingbirds in the area, mostly Anna's Hummingbirds.
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