Sherman and Bethel Islands 2/12 Swamp Sparrow, Lawrence's Goldfinch, Sac co Allen's Hummingbird (population?)
Spent Wednesday, February 12th exploring parts of the Delta in Sacramento and Contra Costa counties, focusing on Sherman and Bethel Islands. Overall diversity was quite high, and passerine activity was good (due to calm conditions) but waterbirds in many of the channels were relatively sparse compared to normal.
The first few hours of the morning were spent at Sherman Island. I started just before sunrise on West Levee Road birding for passerines and hoping to catch a bit of blackbird flight. While I was a little late for Blackbird flight (had fewer than 20k), there were still good numbers of passerines around and a decent raft of waterfowl way out on the river. From there I checked the entirety of East Levee road, checking every patch of habitat that looked solid. Shorebird habitat, primarily on E Levee Road, remains solid but many of the birds were very far out today and hard to ID. Over the course of birding the island, I found the following birds of interest:
Greater Scaup-113 was a solid count here
Common Merganser-20 was a decent count here
Ring-necked Pheasant-3 was a decent count of these quickly declining species in the delta
Mew Gull-3 was way way down from a month ago
Common Gallinule-1 on W levee road was a good bird for sherman
Rufous Hummingbird-1 male was a somewhat early migrant
ALLEN'S HUMMINGBIRD-1 adult male here was the first I have found on Sherman. There were four /Selasphorus/ here, two of which were female-types which I believe were likely also Allen's. If these birds persist through the summer this could represent one of few county breeding records.
Allen's/Rufous Hummingbird-2 at ALHU spot
Red-breasted Sapsucker-1 on east levee road
Acorn Woodpecker-3 at small sherman population on NE side of island
Bewick's Wren-2 were uncommon on the island
'Yellow-billed' White-crowned Sparrow-13
California Towhee-2 represented part of an increasing delta island population
Red-winged Blackbird-19000 in morning flight was a relatively low count for here, likely reflecting my late (circa 7am) arrival
Great-tailed Grackle-14 was part of the expansion of this species into the delta in recent years
Full eBird lists here:
From Sherman I continued onto Contra Costa county onto Jersey Island Road. On the Island, both the road running east along the levee and the road running through the center of the island were open. Along Jersey Island road I found a few surprises including:
Burrowing Owl-2 were the first I've seen in Northeast Contra Costa county
LAWRENCE'S GOLDFINCH-1 south of the island was a very rare bird for the delta
Full eBird lists here:
From there I continued on to Bethel Island where I spent the rest of the day. I started at Piper Slough, went to the flooded fields along Harbor Road, Willowest Marina, checked Frank's Tract, hit both the southwestern and the southeastern neighborhoods and then returned to Piper Slough for dusk. Waterbird numbers on Frank's Tract and Piper Slough were decently high. Despite the time of day I still manage to eek out a good number of passerines. Highlights here included:
Duck sp-2000+ on Frank's Tract. Many Scaup, Ruddies, and Bufflehead mixed in
Allen's Hummingbird-5 males and 2 /selasphorus/ at willowest was a high count here. Males were displaying throughout the typical area north of the parking lot as well as 2 on the south side of the parking lot
American Coot-24000 was an about average count
Glaucous-winged Gull-1 was my first for the island
BALD EAGLE-1 juv was my first for northeast Contra Costa, and the delta islands as a whole. This species is still rare in the region (though increasing)
Red-breasted Sapsucker-1 is a good bird for the island
SWAMP SPARROW-1 very vocal bird here 38.0214482, -121.6095630 was my first for east county. This bird could likely be seen with persistence
Full eBird checklist here: https://ebird.org/checklist/S64411413
Found 126 species bouncing around throughout the day. Always a good day in the delta.
San Francisco, CA
The Solano County BBA has Allen's Hummer as 'Probable' clear up to Rio Vista and 'Confirmed' near Collinsville (or across the river from Pittsburg').toggle quoted messageShow quoted text
Another surprising breeding confirmation comes from Vacaville.
My copy of the CC County atlas is out on loan but would be interesting to check.