May 1998 Field Journal

5.1 Re: Tennesse Warbler
Yes, but I didn't see your bird. I saw what appeared to be an obvious Orange-crowned Warbler,
but noticed (briefly) that it had white undertail coverts. Given that I only
saw the bird for about 2 seconds, I was reluctant to call it, particularly since
that plumage is what I would expect in the fall rather than in springtime.

I think this one will be in the "unidentified" category. :-(

5.2 Little Gull
Technical Details:
Species: Little Gull Larus minutus
Date Observed: 5/2/98
Observer: Mark Eaton
Other observers: Les Chibana, Barbara and Bob Brandiff and others. Unfortunately, due to the distance from the bird and the looming rain squall, none of them were able to get on the bird.
Location: Salt Pond A18, in the city of Alviso, east of the Alviso Environmental Education Center
Time Observed: Approximately 11:15 AM, for only about a minute or less
Lighting: Light overcast, affording good light for duration of the observation, then deteriorating rapidly with the onset of a rain squall.
Weather: Overcast and relatively calm
Optics: Swarovski AT80HD, zoomed up around 50x
Distance: A good 400 yards or more

Below are the field notes from memory. Inclement weather prevented
more immediate documentation. Also, due to the extreme distance from
the bird, some details were not observed. However, due to the fact
that the bird was in the immediate presence of other identifiable
birds, a precise determination of size differences was possible.

Description: A small, black-headed gull closely resembling a
Bonaparte's Gull, with the following essential differences. Size was
roughly 20% smaller than the adult Bonaparte's Gulls. Black head
extending well down the nape, almost to the back of the bird, much
farther than would be present on a Bonaparte's Gull. Absence or
presence of eye crescents impossible at this range. Bill entirely
dark and smaller than on a Bonaparte's Gull. Primaries definitely not
black, but unable to differentiate between mantle color and something
even paler. Wing linings uniformly dark gray all of the way from the
wing tips to the axillaries.

Vocalization: None noted (nor possible)

Behavior: The bird was swimming (and perhaps feeding) within a large
flock of Bonaparte's Gulls in the salt pond. Observation ceased
during the rain squall, and immediately after the squall, the flock
took flight, and many left the area. The bird could not be relocated
after the squall.

Habitat: Salt marsh and salt ponds, ideal for migrating shorebirds and
gulls.

Discussion: Given the extreme distance of observation and the lack of
field experience with the species, such a brief observation might be
viewed with some skepticism. However, the location of the bird in the
immediate presence of gulls of similar appearance and known identity
allowed a precise determination of the bird's identity.

Of the six North American black-headed gulls, only Little Gull is
smaller in size than Bonaparte's Gull. The combination of size, dark
nape, smaller bill, non-black primaries and dark wing linings uniquely
identify it within the expected North American species. Given that
Little Gull is the smallest of the world's gulls, it is unlikely given
the precise size determination in combination with other field marks
that it is any other species even from outside North America.

The full black hood identifies the bird as being in either second
summer or adult summer plumage, while the fully dark wing linings
indicate adult summer plumage.

5.3 [SFBirds] WHAT A DAY!
I guess I'm the first one to hit the e-mail. Most of you know from
phone messages what was seen today. Mt. Davidson sported a number of
views of Black-headed Grosebeak including a pair just below the summit.
Best of all was a Townsend's Solitaire in the forest below the cross.
It stayed in the shade and flew from tree to tree well down hill from
us. As we went looking for it we spottted a Cassin's Vireo working the
canopy to the left of one of the small informal trails which goes down
in the general direction of the main trail. There was at least a single
Pacific-slope Flycatcher there too.

At Glen Park we had a Lazuli Bunting and a Bullock's Oriole at the back
of the canyon. Just before the boardwalk entering the willow grove hike
up the trail above the willow grove. Both birds worked the eucalyptus
to the right and the shrub groves up the hill.

Best, Dan

5.3 [SFBirds] Re: WHAT A DAY!
To add on to Dan's message -- some of us felt that the young Turks in the SF
Birding competition were seeing way too many birds, so we decided to see a
few ourselves...

The SF Birding pack covered good parts of the City today. Mark, Harry and I
met at the Cliff House this morning, where we had numbers of cormorants
offshore but nothing too terribly interesting. Two CANADA GEESE dropped by,
and three TATTLERS were in various locations along the shore and out on the
rocks. We ran into David and Matthew Mattieson, and all tried for Harry's
Ash-throated Flycatcher of last evening, to no avail. Mark, Harry & I
adjourned to the Presidio, where we had a HOODED ORIOLE chasing a SCRUB JAY
chasing a STELLER'S JAY. Got great looks at the Stellers. Also, V-G
Swallows and Tree Swallows apparently looking for places to nest, and lots
(6?) of Hooded Orioles. CALIFORNIA QUAIL were also calling and strolling
around.

Off to Mt Davidson, where our attempts to locate the incessantly calling
Pygmy Owl yielded Hugh and Dan M. As Dan mentioned, we had a nice time
there -- in addition to the great birds he mentioned, we had several
Olive-sided FCs and one Western Wood-pewee.

Glen Park also had a pair of Warbling Vireo in the willows, and a calling
Hutton's Vireo in some eucs. Also, a very late Golden-crowned Sparrow,
perhaps the last we'll see of his kind until the fall, and several
Band-tailed Pigeon flyovers.

Mark and I then went out to Pier 98 (after an excellent lunch in Glen Park
at a place called "A Nice Little Place to Eat"), where we refound the single
Semi-palm Plover (thanks Hugh and Dan), had fledgling Red-wing blackbirds
and Killdeer, and 62 (!) Forsters Terns. Low tide didn't give us much on
the shorebird front, either -- a distant Whimbrel and one spotty, but pretty
quiet other than that.

Great birding -- and although I know no one is keeping track, I managed to
pick up eight (8) new city birds today...

See you in the field --

Luke

5.3 [SFBirds] Re: WHAT A DAY!

Not much to add other than Harry graciously showed us the STELLER'S JAYS in
the Presidio. We had an interesting view of a HOODED ORIOLE chasing a SCRUB JAY
chasing a STELLER'S JAY, or some combination thereof.

5.12 [SFBirds] ASH does it again...
He called me earlier today to mention that he (somehow) found an ARCTIC TERN
off the Cliff House in between one of the deluges today.

Other birds were CASSIN'S VIREO along Hayes Street, MACGILLIVRAY'S WARBLER
in the willows at the south end of Lake Merced and significant numbers of
shearwaters far offshore at Fort Funston. Call Alan for more info...

5.18 [SFBirds] Re: Hooded Warbler in Mountain Lake Park
Let me preface this discussion by saying I did NOT observe the bird, even poorly. The only thing that I managed to see is movement of a (probable) Warbler low in the willows near where we were all standing. I had the misfortune of being slightly down the rise and focused on the area to the left of the shed and not the right when the bird appeared. If I called Hooded Warbler, it was out of speculation or excitement rather than observation and identification.

Having said that, based on the discussion with David and Joost, I believe that this was in fact a HOODED WARBLER. David described well that the bird fanned its tail widely, and, given that the bird was totally in shadow, I have to believe that he did indeed see white on the tail when it was fanned.

Now for the bad news. This bird was seen for maybe 5 seconds total out of 1 1/2 hours. The weeds are quite large and the willow thickets are as thick as any in SF. Good vantage points are few and far between. In Joe's words, this bird might be a project. Taping might be an option.

Simplified directions follow:
- Park anywhere off of Lake Street near 9th or 10th Avenue
- Make your way due north until you hit the path and the chain link fence which separates the golf course from the park - Walk west on the path to the east end of the lake whereupon the trail forks
- Take the fork which goes to the right (northwest)
- Follow this fork for about 100 yards until you find (any of) dead pine tree, obvious dilapidated shed, chain link fence ending at left side of trail. The shed has red graffiti on it and the numerals 348 on it (much as a street address).

I believe all sightings have been in the immediate vicinity of the shed.

Of lesser news (but helping to pass the time):
Yellow Warbler, in the willows in the middle of the thicket on the east end
Cassin's Vireo, at least one, perhaps two, about 20 yards north of the shed
American Goldfinch, one female (?) that appeared to be gathering nesting material. This
bird appeared still to be in winter plumage (?) The legs on this bird were pale flesh/bone colored.
Lesser Goldfinch, several
Townsend's Warbler, one seen, at least two more heard. Isn't 5.18 a bit late for these guys?

5.18 [SFBirds] Hooded Warbler Booby Prize; Ringed Teal
I was less than bristling (groan :-) with excitement after work today so I
headed out to Stowe Lake and managed to refind the male RINGED TEAL,
swimming alone along the southern edge of the lake.

Best real birds; a very cooperative PACIFIC-SLOPE FLYCATCHER and a likewise
BLACK-CROWNED NIGHT HERON, both on Strawberry Hill.

5.23 - 25 Eastern Sierra Nevada
Here's a brief summary of the trip I had to the Eastern Sierra Nevada over Memorial Day.

Unexpected or difficult to find:

Expected though interesting:

Clearly, the highlight of the trip was to Tom's Place. From [GAI]

"Status uncertain: one positive record on the west slope"

and

"While there is but a single record, I suspect COSTA'S HUMMINGBIRDS are rare but regular visitors both west and east of the coast."

Documentation for this sighting is available separately. BLACK-CHINNED
HUMMINBIRD is also listed as [GAI]:

"Rare summer resident ... below 7000' east of crest"

Finally, BROAD-TAILED HUMMINBIRD is listed as [GAI]:

"Locally rare summer resident below 8500' feet."

but "established" at the Tom's Place feeders. Clearly, this was a trip for hummingbirds!

There were several GREAT-TAILED GRACKLES at the freshwater marsh at Benton Hot Springs; [GAI] suggests:

"Extremely rare vagrant east of Sierran escarpment."

though the GREAT-TAILED GRACKLES are clearly established at Benton Hot Springs. DUSKY FLYCATCHERS were easy to see at Tioga Lodge, cooperating with good locks for critical observation and there was a MACGILLIVRAY'S WARBLER probably moving through in the sage south of the Tioga Lodge.

The SORA was heard in the above-mentioned marsh, GREEN-TAILED TOWHEES were easy to find in Horse Meadows and elsewhere. BREWER'S SPARROWS couldn't be avoided if you did any walking whatsoever in the sage, and this appears to be a good year for SAGE SPARROWS as well. We also had a single THICK-BILLED FOX SPARROW while descending from Sonora Pass.

While there were a few notable dips (SAGE GROUSE, GRAY FLYCATCHER, JUNIPER TITMOUSE), and we didn't have time to try for GRAY-CROWNED ROSY FINCH or BLUE GROUSE, the spectacular scenery and low season rates and tourist congestion made for an extremely enjoyable visit.

Mark
---------------
[GAI] David Gaines, Birds of Yosemite and the East Slope, Artemisia Press, Illustrated by Keith F. Hansen

5.24 Costa's Hummingbird
Technical Details:
Species: Costa's Hummingbird _Calypte costae_
Date Observed: 5/24/98
Observers: Mark Eaton, Debi Lamm
Other observers None.
Location: Feeders in the trailer park at Tom's Place [MNO]. This sighting was at the feeder to the rear of the trailer, only a yard or so south from the rushing creek at the northern edge of the trailer park.
Time Observed: Twice during the period of 5:00 PM to 6:00 PM for only about 15 seconds each observation
Lighting: Nearly ideal. There was clear blue sky and the sun was relatively low and at right angles from the viewing area. The iridescence on the male hummingbird gorgets was easily noticeable.
Weather: Bright sunshine and a good breeze, the latter mitigated significantly by the mature aspens in the area.
Optics: Swarovski 10x42 SLC and Celestron 9.5x42 ED
Distance: I had to step back on one occasion while observing a different bird for sharp focus. Most of the observations were from about 20 feet.
Bird/sun/viewer orientation: In both cases, the bird was nearly perpendicular to us with the sun shining more or less directly on the gorget.

Below are the field notes from memory.

Description: A green-backed hummingbird with a prominent gorget. The
coloration of the gorget was deep amethyst/purple and the gorget
extended both above and below the bill. The gorget below the bill was
significantly elongated along the sides of the neck, tapering to
just cover the throat at the center of the lower gorget. The
elongation/tapering of the gorget gave the impression of handlebars on
a cruiser-style bicycle. The amount of the elongation I judged to be
at least 50% of the length of the gorget at the center of the throat.
The gorget above the head appeared to end at roughly at the top of the
eye, but I can not be certain of this. Immediately above and to the
rear of the eye, there appeared to be a small patch of feathers
similar to the gorget feathers as they showed the same iridescence as
the rest of the gorget. No buff or warm tones were observed on any
part of the bird. Details of the tail were not observed due to a
combination of the bird not fanning its tail during the observations,
the relative orientation of the bird and the brevity of the
observations. Bill all dark and slightly and uniformly decurved over
the entire length

Vocalization/wing noise: Unfortunately, none noted. Due to the heavy
snowfall this year and the immediate proximity of the feeder to the
vigorously flowing creek, hearing anything above the din of the creek
was not possible.

Behavior: The bird appeared twice at the same feeder to feed. After
roughly 15 seconds each observation, it then rapidly disappeared from
sight.

Habitat: The Tom's place feeders should be construed as in a riparian
region due to the immediate vicinity to the creek. Immediately
outside of this is sage or sage-like plants typical of high desert in
the Great Basin, though it is certainly close in proximity to the
Mountain region of the Sierra Nevada [MDEM].

Discussion: Only Lucifer Hummingbird _Calothorax lucifer_,
Black-chinned Hummingbird _Archilochus alexandri_, Costa's Hummingbird
and Calliope Hummingbird _Stellula calliope_ have gorgets which are
more purple than red. For Black-chinned Hummingbird, most of the
gorget is actually black, with only small fraction at the base of the
throat being purple and the gorget is not elongated. For direct
comparison, there was also a male Black-chinned Hummingbird observed
during the same period which clearly showed the black/purple
separation of the gorget.

Lucifer Hummingbird has a purplish lower gorget, but even the adult
males show some rusty or buff on the flanks. As well, Lucifer
Hummingbird has a green cap and the bill is considerably decurved.
Calliope Hummingbird also has a purplish lower gorget, but the lower
gorget is streaked in rays rather than solid feathers. As well, the
size is very small, the tail is very short and the cap is green. I was
fortunate also to observe an adult male Calliope Hummingbird during
this same period. The identification as a Costa's Hummingbird would
seem to be the only plausible identification.

Interestingly enough, the drawings in neither of the standard field
guides [NGS], [PET] show the spot of like-colored gorget feathers
immediately above and to the rear of the eye. However, the photgraph
at close range in [AUD] clearly shows such a patch of feathers, such
as was observed on this bird.

References:
[AUD] The Audubon Society, Master Guide to Birding, Edited by John
Farrand, Jr.
[MDEM] McCaskie, DeBenedictis, Erickson and Morlan, Birds of Northern
California, Reprinted with Supplement, April 1988
[NGS] National Geographic Society, Field Guide to the Birds of North
America, Second Edition
[PET] Roger Tory Peterson, Western Birds, Third Edition, Houghton
Mifflin

5.29 [SFBirds] Indigo Bunting at East Wash
After meeting Luke exiting from the wash just as I arrived and hearing of his lack of success, I nonetheless headed down into the wash. I thrashed around at the base of the willows for about 15 minutes before heading for easier walking in the devastated zone directly below the cart path which separates the wash from the golf course.

At this point, I saw an small bunting flying directly up the length of willows to perch on a snag just south and west of north end of the willows. In flight, it was all deep blue/indigo, with no contrast on the back. From the perch, I had a good if somewhat odd view of the bird as I was downslope (i.e. below) the bird.

The bill from that angle appeared all pale, perhaps due to being below the bird or perhaps not. There was a small black mask surrounging the bill. The belly and throat were all uniformly deep blue, with no contrasting areas observed on the belly. The wings were darker colored than the rest of the bird and showed no hint of contrasting wing bars, but I could not tell if they were a deeper shade of blue or black. I managed one attempt at a photograph which will be of dubious quality but perhaps identifiable.

The bird then flew farther upslope, across the cart path between the wash and the golf course and appeared to land in one of the mature cypresses at the juction of the road and Lincoln Blvd. However, I lost track of the bird at that point. I then amused myself for awhile by tromping around in the brush and listening and observing the WESTERN WOOD-PEWEE. After about another 15 minutes, I then briefly saw the bird again fly from a point near the bottom of the willows to another perch in a cypress at the edge of the golf course near where the trail leads from the cart path into the east wash proper. I could not refind the bird after this.

I have no doubt this was an adult male INDIGO BUNTING, though am slighly troubled by the bill coloration as I did not notice any contrast between the upper and lower mandibles. The deep uniform blue coloration eliminates most other species and the lack of wing bars eliminates LAZULI BUNTING. LAZULI BUNTING also shows contrast between the nap and the back, which I did not observe. Lack of wingbars and size also eliminate BLUE GROSBEAK. BLUE BUNTING (yeah, right :-) is perhaps a possibility, but I noticed neither a strongly curved culmen nor any contrast between the blue areas on the body.

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