6.5 Eastern SF
Today, I was looking for some sun
and possibly something of interest at the edge of the fog. I
started at Bayview Hill and found a pair of SPOTTED TOWHEES.
The female, sans tail, was nonetheless carrying food to some
unseen nest site in the area uphill from the steep ascent from
the end of Key. This is the first breeding confirmation I'm aware
of for block 5070 and the first breeding confirmation I'm aware
of since the atlas period.
At the Caspian Tern colony (what pier was that, anyway???), two women (sorry, no names) were monitoring the colony and they had 25 CASPIAN TERN chicks at the colony, so it seems like the colony is quite successful this year. At the west end of Crissy Field, there were 5 CEDWAR WAXWINGs that seemed on the late side.
Bayview Hill
Spotted Towhee 2 CO-CF
Western Wood-Pewee
Pier ???
Caspian Tern 40, 25 chicks
Crissy Field
Cedar Waxwing 5
6.12 Little Gull
This morning, I headed down to Pescadero Marsh where I found
a small armada of birders and the gulls flying out just as I
arrived. Fortunately, the LITTLE GULL remained, almost comatose,
on the north side of Pescadero Creek just west of the Hwy. 1
bridge. After exchanging pleasantries with Paul Saraceni and
others, I headed down to an area on the beach partially sheltered
by driftwood shelters from which these photos of the Little Gull
were taken.
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Little Gull ©2004 Mark W. Eaton
Notes from memory of the sighting:
A very delicate gull strongly resembling a Bonaparte's Gull. The bird had a fine black bill showing almost no gonydeal angle. The head was white, streaked black on the crown and with an unusual facial pattern. There was a gray post-ocular spot as well as a dark ocular spot. The scapular feathers were pale gray, floppy, and in some places hung well over the wing coverts. The scapulars looked quite fresh, in abject contrast to the wing coverts. The wing coverts were almost jet black, showing quite a bit of wear near the tips so that the feather shafts were visible. There was a small pale band that appeared to coincide with the marginal coverts on the folded wing.The high-contrast back or side lighting and Rayleigh scattering off of the morning air made determination of the wing pattern somewhat confusing as one wing tip appeared to be pale while the other one was dark with no pale edges. Upon further reflection, the pale wing tip in fact was the underside of the wing tip of the far wing and the upper wing of the primaries was indeed all dark. There was some dark on the tail, but the viewing angle of the bird prevented a more detailed description of the upper tail pattern. The undertail, belly, breast and throat were all unmarked white. The legs were bright red. Unfortunately, I was not able to see the bird fly or even flap its wings during the hour plus observation. However, at one point, a Red-necked Phalarope walked very close to the bird and was not significantly different in size (see photo below).
Analysis:
For completeness, terns should be discussed, but no species of regularly-ocurring tern in North America has such a broad-black bar spanning the wing coverts in any plumage. So we're left with gulls. The bird is clearly not in adult plumage; no adult gull shows the aforementioned wing covert bar. More likely, it is in first winter or first summer plumage. First winter Ross's Gull (how lucky can you get? :-), shows no streaking on the head, prominent black centers on the termitals and quite a bit of white on the primaries in first winter plumage. First winter Black-legged Kittiwake shows some black on the lesser and marginal coverts, but the greater and median coverts are gray. Also, first winter birds have a broad black band at the rear of the neck. first winter Ring-billed Gull has a pale bill with a yellow tip, yellowish legs and is a much larger bird. first winter Mew Gull lacks the black coverts and the head pattern.Finally, we're left with the first winter small hooded gulls, which is what the initial impression was anyway. Black-headed Gull is an interesting suggestion. However, a Black-headed Gull has an orange-red bill, lacks an extensive black cap and would tower over a Red-necked Phalarope. Bonaparte's Gull is really the only source of confusion. However, first winter birds lack any black on the cap and the black on the wing coverts is restricted to only a few feather tracts. First summer birds have molted the retained juvenile coverts and also have very little suggestion of a black hood. Finally, we're left with Little Gull. Appropriately named, it would be the only small hooded gull that would be likely to be perceived to be the same size as a Red-necked Phalarope. In first winter plumage, it shows a strong contrast between the streaking on the cap and a strong black bar covering most of the wing coverts. By June, the bird would show quite a bit of wear on the retained juvenile coverts, but the first winter coverts would appear much fresher. First summer Little Gull would show some of the adult head pattern and the amount of black on the wing coverts would be much reduced, suggesting that the bird observed was a LITTLE GULL, still retaining first winter plumage.
Little Gull ©2004 Mark W. Eaton
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Little Gull ©2004 Mark W. Eaton; the bird in the upper
right hand corner is a Red-necked Phalarope
6.19 Pair of Rose-breasted Grosbeaks
This morning on Mt. Davidson there
was a female ROSE-BREASTED GROSBEAK in the elderberries and eucs
near the top of the ravine trail. There was a another singing
adult male in Glen Canyon Park. The Audubon's YELLOW-RUMPED WARBLER
continues its lonely vigil on Mt. Davidson and there were OLIVE-SIDED
FLYCATCHERS at both locations.
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