8.2 [SFBirds] Re: [SFBirds] Mt. Davidson,
08/02/00 (6:50-8:10 AM)
Paul Saraceni wrote:
>
> Hints of passerine migration and the first fog-free morning
visit in weeks.
>
> Observations of local interest:
>
> HERMIT WARBLER 1 imm. (post-breeding wanderer from Marin
Co. or Santa Cruz
> Mtns.??)
If recollection servces, HEWA do come through
early (i.e. in August) but I think
this is too early even for that. If someone has 'Birds of California'
by
McCaskie & Morlan, it might be fun to check...
8.5 [SFBirds] Another large larid congregation
I almost forgot, but from my vantage
point high in the seats at PacBell on
Thursday night, there was a large (dominantly) larid concentration
on one of the
piers not far south from PacBell. If you were interested in
searching for these
birds, go east at the first street south of the 3rd street bridge
immediately
southwest of Pacbell and search each pier that's visible from
the easternmost
street.
Nothing else of interest at PacBell; had BARN
SWALLOWS (nesting?) (but no
WHITE-THROATED SWIFTS) at the park before dusk.
8.18 - 20
Yuba Pass and Eastern Sierra Nevada
121 species seen:
Pied-billed Grebe (7)
Eared Grebe (12)
Western Grebe (10)
Clark's Grebe (9)
American White Pelican (9)
Double-crested Cormorant (9)
American Bittern (7)
Great Egret (10)
Snowy Egret (10)
Black-crowned Night-Heron (7)
White-faced Ibis (7)
Turkey Vulture (7)
Canada Goose (9)
Gadwall (10)
Mallard (7)
Ruddy Duck (10)
Osprey (5)
Northern Harrier (17)
Sharp-shinned Hawk (2)
Red-tailed Hawk (8)
American Kestrel (6)
Prairie Falcon (14)
Greater Sage-Grouse (26)
Mountain Quail (1)
California Quail (23)
American Coot (7)
Sandhill Crane (7)
Killdeer (7)
Black-necked Stilt (21)
American Avocet (10)
Greater Yellowlegs (10)
Lesser Yellowlegs (10)
Willet (21)
Spotted Sandpiper (16)
Marbled Godwit (9)
Common Snipe (11)
Red-necked Phalarope (12)
California Gull (9)
Caspian Tern (9)
Common Tern (10)
Great Horned Owl (23)
Common Nighthawk (14)
Common Poorwill (13)
Black-chinned Hummingbird (20)
Anna's Hummingbird (3)
Costa's Hummingbird (20)
Calliope Hummingbird (3)
Rufous Hummingbird (3)
Belted Kingfisher (1)
Red-breasted Sapsucker (1)
Downy Woodpecker (23)
White-headed Woodpecker (2)
Northern Flicker (5)
Olive-sided Flycatcher (2)
Western Wood-Pewee (2, 23)
Willow Flycatcher (1)
Hammond's Flycatcher (2)
Dusky Flycatcher (2)
Black Phoebe (18)
Say's Phoebe (15)
Ash-throated Flycatcher (1, 18)
Loggerhead Shrike (14)
Cassin's Vireo (1)
Warbling Vireo (1)
Steller's Jay (1)
Pinyon Jay (10)
Clark's Nutcracker (11)
Black-billed Magpie (9)
Common Raven (10)
Horned Lark (7)
Violet-green Swallow (9)
Northern Rough-winged Swallow (17)
Bank Swallow (18)
Cliff Swallow (17)
Barn Swallow (7)
Mountain Chickadee (1)
Juniper Titmouse (8)
Bushtit (8)
Red-breasted Nuthatch (1)
Pygmy Nuthatch (25)
Brown Creeper (2)
Canyon Wren (19)
Bewick's Wren (1)
House Wren (23)
Marsh Wren (7)
Golden-crowned Kinglet (27)
Ruby-crowned Kinglet (1)
Mountain Bluebird (22)
Townsend's Solitaire (23)
American Robin (5)
Sage Thrasher (12)
Le Conte's Thrasher (18)
European Starling (7)
Orange-crowned Warbler (1)
Nashville Warbler (23)
Yellow Warbler (4)
Yellow-rumped Warbler (1)
Hermit Warbler (1)
MacGillivray's Warbler (1)
Wilson's Warbler (23)
Green-tailed Towhee (24)
Spotted Towhee (23)
Chipping Sparrow (2)
Brewer's Sparrow (15)
Vesper Sparrow (6)
Savannah Sparrow (7)
Fox Sparrow (4)
Song Sparrow (1)
Lincoln's Sparrow (1)
Dark-eyed Junco (1)
Lazuli Bunting (17)
Red-winged Blackbird (10)
Western Meadowlark (6)
Yellow-headed Blackbird (10)
Brewer's Blackbird (6)
Great-tailed Grackle (10)
Bullock's Oriole (15)
House Finch (10)
Pine Siskin (1)
Evening Grosbeak (1)
Coyote (12)
Locations:
1) Basset's (Aug 18)
2) Yuba Pass (Aug 18)
3) Bassett's (Aug 18)
4) Gold Lake Road (Aug 18)
5) Salmon Lake Road (Aug 18)
6) Calpine Corner (Aug 18)
7) Dyson Lane (Aug 18)
8) Red Rock Canyon (Aug 18)
9) Topaz Lake (Aug 18)
10) Bridgeport Reservoir (Aug 18)
11) 395 (Aug 18)
12) Black Point (Aug 18)
13) Hwy. 120 (Aug 19)
14) Fish Lake Valley (Aug 19)
15) Oasis (Aug 19)
16) Fish Lake Ranch (Aug 19)
17) Deep Springs (Aug 19)
18) Fish Slough (Aug 19)
19) Paradise (Aug 19)
20) Tom's Place (Aug 19)
21) Crowley Lake (Aug 19)
22) Hwy 120 (Aug 19)
23) Mono County Park (Aug 20)
24) South Tufa (Aug 20)
25) Jeffrey Pines (Aug 20)
26) Parker Creek (Aug 20)
27) Siesta Lake (Aug 20)
8.19 LeConte's
Thrasher, Fish Slough, MNO
Steve Gerstle and I were birding the
eastern side of the Sierra Nevada when we decided to search for
the LeCONTE''S THRASHER that had been reported on and off earlier
that summer. After a four hour detour to Fish Lake Valley, we
finally found the correct location in Fish Slough. We walked
along the northern edge of the corral when suddenly we heard
a thrasher-like call. We found the source of the call and got
decent looks at a very retiring bird, quite rare in Northern
California.
.jpg)
8.22 [SFBirds] Costa's yes, pictures no...
I overslept my alarm and didn't get
up there until 8:00 or so, presumably missing Paul if he was
there this morning. I found magic spot in fairly short order
and the COSTA'S HUMMINGBIRD flew in not long thereafter. However,
my experience was more or less a repeat of Dan Murphy's; the
Costa's Hummingbird was driven off by two agressive selasphorous
hummingbirds, though my look was more in the 5 to 10 second range
than 2 seconds :-)
Based on this brief observation, I can add nothing to the excellent commentary so far on this bird. In particular, my view was directly head on, affording a fine view of the oft-mentioned inverted vee of gorget feathers, but only a peripheral view of the grayish-green back.
However, perhaps I do have some additional value to add to this discussion. While I have seen quite a few immature Black-chinned Hummingbirds, I have limited experience with Costa's Hummingbird, and perhaps none with immatures. However, this weekend past, I was fortunate to visit the infamous feeders at Tom's Place in southern Mono county. My observation lasted over an hour with the bulk of the birds coming to feeders in light shade during the midday on a typically brilliant, cloud-free August day in the Eastern Sierra.
After watching at least one and probably more immature Black-chinned Hummingbird come to the feeders, another bird came to the feeders which immediately stood out from the Black-chin ned Hummingbird. It was very gray-green on the back, marked differnt from the coloration on the back of a Black-chinned Hummingbird. As well, the underparts were very white, showin g little grayish on any parts of the flanks. The throat was quite white, showing little evidence of streaking (and no inverted vee of gorget feathers). I seem to recall it perching on the feeder once, and the primary extension seemed to reach the tail, but not beyond. If the bird was not at the feeder at the same time with the Black-chinned Hummingbird, it was certainly there within a few minutes, if not s econds of a Black-chinned Hummingbird.
I identified this bird as an immature/female COSTA'S HUMMINGBIRD. With the exception of the gorget feathers on Mt. Davidson bird, this is bird was pretty darn close to the composite description on this forum and certainly fully consistent with the bird I saw this morning. I'm tempted to say that the back color alone is almost sufficient to separate the two, but the combination of the field marks mentioned seem pretty unambigous to me. In particular, I think the Tom's Place bird is particularly relevant since it was at the same time of year, so any issues of molt or fading should be negligible to first order. Finally, I found an excellent photo of a female Costa's Hummingbird on the web.
While the face is a little overexposed, notice the white above the eye, the grayish-green back and fairly long primary extension. This is pretty much a dead ringer for the Tom's Place bird and if you paste on some gorget feathers, pretty good for the Mt. Davidson bird too.
8.22 [SFBirds] One other note...
...I also had an unseen hummingbird
fly near my head and make a sharp "zinging"
noise as it flew by. While I can't correlate this with the Costa's,
I certainly
have never heard this from an Allen's/Rufous or an Anna's.
8.15 - 22 Costa's
Hummingbird, SF
Photographs ©2000 Alan S. Hopkins
I was just about to head up to the
mountains for the weekend when Paul
Saraceni found a COSTA'S HUMMINGBIRD at Mt. Davidson. Paul's
comprehensive description can be found here.
I would have chased it that morning, but fell ill the night before
and could not chase it. Fortunately, I returned from the mountains
to find that the bird was still being seen and saw the bird briefly
on the last day it was seen. :-) I did not manage to get any
photos, but fortunately Alan Hopkins
did. The images are small, resulting in the grainy Web images,
but they show quite a bit of detail, some of it not discussed
in field observations. My commentary from my brief observation
can be found here.
Figure 1
Figure 1 shows the bird in profile. Immediately noticeable is a large white patch above the wing. I'm not aware of this being a useful field mark, but compare the white above the wing with the photo of a known-species female COHU here. Otherwise, the markedly white underparts show up clearly in this photo. Also, if you look carefully, you can see that there is a small dark patch on the otherwise white flanks immediately under the folded wing. Obviously, this would be hard to see in the field when the bird is perched and impossible when the bird is flight.
Figure 2
Figure 2 shows a mostly dorsal view of the bird preening (or sticking it's foot in it's eye if you believe the scan :-) The white above the wing shows quite clearly and the dark patch on the flanks appears as a dark blur immediately to the right of where the wing meets the body. Otherwise, it's kinda of hard to get more detail out of this slide. What color are those throat feathers? I'm not sure I can tell even from the slide.
Figure 3 and 3a
Figures 3 and 3a show a ventral view of the bird, with a nice look at the tail feathers on the perched bird. Again, I don't know if the spots can be used in the identification process, but there they are. Otherwise, I don't think there's much else to comment on from these slides.
Figure 4
Figure 4 is a nice dorsal view of the bird. The bird doesn't look particularly grayish in these photos, but it's hard to tell in bright light. In fact, we can even count the primaries on the folded wing. As well, the dark patch on the flank is clearly visible. The spacing of the primaries can be used to separate female plumaged BCHU from RTHU (see the latest issue of Birding), but I'm not aware of whether or not this is useful for this identification problem.
Figures 5, 5a and 5b
Figures 5, 5a and 5b show the COHU hummingbird along with details of an ANNA'S HUMMINGBIRD and the COHU. I deliberately did not alter the color balance or any other aspect of the details. The COHU certainly does look pot-bellied; again, I don't know how useful this is. Also, the COHU does look grayer, particularly in the head, than the ANHU.
I'm still convinced this is a COSTA'S HUMMINGBIRD; let me know if you disagree.
You can contact me via email.