Yellow Warblers in Berkeley?
Tue, 2 Jun 1998 10:41:09 PDT
From: Doug Greenberg
Hi all--
For the past two weeks there has been a male Yellow warbler present in a large black acacia in my backyard in south Berkeley. Here it is, June 2, and the little guy is still out there, singing every morning. I had assumed that he was a straggler migrant that was still on his way elsewhere, but now I'm starting to wonder. Is it possible that this bird is nesting somewhere nearby? I have not seen a female bird nor any evidence of nesting, but it seems awfully late for a migrant warbler, and this individual has been hanging around for weeks now. What does anyone think?
--Doug Greenberg
Re: Yellow Warblers in Berkeley?
Tue, 02 Jun 1998 14:01:16 -0700
From: Rusty Scalf
As far as I know, Yellow Warbler has been almost completely extirpated as a breeding bird in the lowlands of California. However, Coyote Creek Riparian Station in Alviso had an actual nesting. I forget whether it was last Spring or the spring before.
Apparently Yellow Warblers just get hammered by Cowbirds.
I always think of Yellows as needing stands of deciduous trees. I am told that in the early part of the century, Yellow Warbler was one of the most common if not the most common breeding bird in the riparian forests of the Central Valley. The Sacramento County Breeding Bird Atlas was unable to find any breeding Yellows. That despite large tracts of broadleaf woodland along the Sacramento and American Rivers.
Rusty Scalf
Iron House Field Trip
Tue, 2 Jun 1998 21:45:02 PDT
From: Steve Glover
Atlasers and East Bay Birders,
Sorry for the extremely late notice but if anyone wishes to attend tomorrows Mt. Diablo Audubon field trip to the Iron House Sanitary District in Oakley I would love to have you. We will be meeting at the southwest corner of the Sun Valley Mall parking lot in Concord at 6:45 am. If you don't want to carpool we will be meeting at 7:30 at the treatment plant. To reach the plant take hwy 4 to Oakley. To stay on 4 you will have to actually exit the freeway to avoid going across the Antioch Bridge. In the town of Oakley turn left onto Vintage Parkway. Go over the overpass and turn right onto Walnut Meadows Dr. Go all the way to the end and turn into the plant. Black Rails have been heard on every trip lately. We have a good chance of seeing Bittern, Swainson's Hawk, Blue Grosbeak etc. Perhaps the Grackle will still be present. If time permits we will be going to Piper Slough afterwards in hopes that the Indigo Bunting will still be around.
Hope to see you there.
Steve Glover
Indigo Bunting, Black Rail
Wed, 3 Jun 1998 14:40:01 PDT
From: Steve Glover
Hello all,
Sorry for the late notice on the Iron House Field Trip today. I had forgotten that I even had a trip and remembered just last night.
This morning at Iron House we heard 4 singing Black Rails. Judging by their locations there are at least 7 male Black Rails around the back of the property, this area being known as Big Break. Amongst many broods of Mallard was a brood of Gadwall, a pretty rare and local nesting species in the county. A late fem[ale] Bufflehead was also present. It will be interesting to see if it summers since I know of no summer records of this species for the county. Four White Pelicans were seen flying west. There are only 2 or 3 county records that I know of for the month of June and even those were late June. There are several records from the salt ponds of [southern Alameda County] from as early (late?) as late May. Does anyone have any comment on why White Pelicans are present in late May and early June in some years? Are they very late? Are they extremely early returnees? Are they birds that aren't breeding this year at all? On the walk out to the ponds there were about 50 Cliff Swallows in the area. On the return trip there was a swarm of about 350.
We birded briefly at Piper Slough and were surprised to see a (the?) male Indigo Bunting along Bethel Is[land] Rd. The bird was in the large patch of blackberry bushes near the gas well just before the north end of the road. It quickly flew back toward where we saw it Sat[urday] so it probably is the same bird. The only migrant passerine on the day was a Pac[ific]-slope Flycatcher.
Happy birding,
Steve Glover
Cormorants nesting at Lake Merritt
Thu, 4 Jun 1998 07:35:16 -0700
From: Larry Tunstall
I just received an e-mail from Pablo Cepero, Supervising Naturalist at Lake Merritt Waterbird Refuge in Oakland. He says that there are about 12 cormorant nests amongst the twenty-something Great Egret nests on the islands near the Rotary Nature Center. I'm sure these would be Double-crested Cormorants; I've never seen any other kind at Lake Merritt.
Rex Burress, retired naturalist, says that this is the first time he's seen cormorant nests at Lake Merritt in the 30 years he's been checking on the nesting egrets.
Larry
collegiate Cooper's hawks
Thu, 4 Jun 1998 11:41:18 -0700 (PDT)
From: Emilie
For the fifth consecutive year, the [University of California - Berkeley] campus [Cooper's Hawk] nest is producing young. Today I easily saw four "downy blobs" bouncing around in the nest . The nest is located in a large eucalyptus tree just south of the undergraduate library, which is near the main library and is more or less in the center of campus. Just look for the whitewash and then look up. Normally, I wouldn't advertise the nest of a sensitive species like this, but these birds seem to be very habituated to humans (although the adults have dive-bombed a few people this year). There were also [Song Sparrows] carrying food, violet-green swallows over Strawberry Creek, and singing robins, purple finches, and [dark-eyed] juncos.
HaDu, ElTe and return of the Arctic Tern
Thu, 4 Jun 1998 12:56:59 PDT
From: Steve Glover
Hello all,
This morning I scoped Brooks Is[land] from the end of Marina Way (the scene of more bulldozing). The conditions were perfect with the overcast to hide the sun and a complete lack of wind. I saw the resident male Harlequin Duck on the beach to the left of the dilapidated of pier with about 25 Surf Scoters. There was a total of 225 Surf Scoters in the area along with one male White-winged.
There were also 125+ Elegant Terns on the island amongst the 300+/- Caspians. Grinnell and Miller state that through 1945 there were but 2 records of this species from San Francisco Bay and that they bred nowhere in the state. Our large numbers of post-breeding Elegants don't seem to have appeared until about 1960. This fits beautifully with the fact that the San Diego Bay colony, the first colony found north of Mexico, was first reported in 1959. Since 1960 the pattern has been for the first post-breeding birds to arrive in the bay in Late June or early July, with peak numbers in September. Spring birds in April or May in the East Bay were virtually accidental. A few early birds might arrive as early as mid-June but never more than a handful. In 1987 a colony of 17 pairs was established at Bolsa Chica, Orange Co. By 1993 there were nearly 2000 pairs! It seems to make sense that we get more Elegants here earlier because there is now a large colony only a few hundred miles away. Unfortunately for the terns, this seems to be too early for such numbers. In the mild El Nino year of 1992 only 92 pairs bred at Bolsa Chica. Apparently most of the birds were as far north as Oregon and Washington. Although I haven't heard it mentioned, it seems likely that the large numbers here already are birds unable to breed for lack of food. Has anyone heard of a nesting failure to the south?
Also seen around Brooks Is. were 2-3 winter plumage Common Loons, An Osprey carrying fish and being chased by both Ravens and Western Gulls, and 2-3 Brown Pelicans. Three singing nutalli White-crowned Sparrows were in the shrubs around the parking lot at the Richmond Marina.
Two Pelagic Cormorants were on West Brothers Is. but neither were on nests. It would appear that either they have abandoned this site for breeding or are also unable to breed this season. Many Western Gulls were seen on nests on the island as well as on many channel markers in the Richmond area. Finally, Bob Richmond mentioned to me that the female Arctic Tern has returned to summer at Hayward [Regional Shoreline] for the 6th straight year!
Steve Glover
Elegant Terns
Thu, 04 Jun 1998 13:13:41 -0700
From: Rusty Scalf
Apparently Elegant Terns are having a disasterous season in southern Calif[ornia]. The Bolsa Chica colony on the Orange County coast produced some 4000+ chicks last year. A good friend who visits the sight regularly tells me that there are perhaps 10% of the numbers of breeding adults as last year.
More than a month ago, Leora Feeney and others counted 1400+ Brown Pelican on the island breakwater at the former Alameda Naval Air Station. Those are the peak numbers of the post breeding wave of late August. Without knowing any particulars (other than Bolsa Chica) my guess is that seabird nesting in the Gulf of Calif and the Channel Islands is about a zero this year.
Rusty Scalf
Berkeley, CA
Re: Cormorants nesting at Lake Merritt
Thu, 4 Jun 1998 14:27:09 -0700 (PDT)
From: Tom Condit
Super! Lake Merritt's been a prime place for seeing double-crested cormorants in breeding plumage for years. It's about time they started nesting!