Contra Costa last week of July misc.
Today, Friday the 30th, I spent my day birding around East Contra
Costa, joined by Srikant Char in the morning at Creekside Park
(Brentwood) and Bradford Island. Creekside Park yielded a handful of
passerine migrants—2 Warbling Vireos, 1 Yellow Warbler, 1 Wilson’s,
and 3 Tanager. Later on Bradford, the only definite passerine
migrants were 1 Lazuli Bunting and 2 Pac. Slopes. The highest
single-scan count of Bank Swallows here was 32, and later 9 Bank were
at Bethel Harbor as well as one newly-arrived drake Canvasback. 5
Chats linger on Bradford; two singing, one carrying food. 600 or so
Tree Swallows were present at Clifton, among them 3 Violet-greens,
down from 6 Violet-green July 19th. Violet-green Swallows are rare in
the delta (at least the section in Contra Costa), and should be
carefully noted, especially when your ratio of Violet-green to Tree
exceeds something around 1:100 which is typically the usual ratio (or
lower). 3 Lesser Scaup also continued today at Clifton.
Yesterday the 29th, despite West winds and a complete marine layer,
conditions previously identified to be bad for migration at Point San
Pablo, passerine migrant numbers were decent--especially for late
July. This was a good reminder of how unpredictable this bayside
birding location can be. Highlights were rare-in-Richmond Ash-throated
Flycatcher and Lawrence’s Goldfinch, among Pac-slopes, Tanager,
Grosbeak, etc. 2 Pigeon Guillemots still in alternate plumage west of
Point Molate Beach Park (the “county park”) were a first for me here,
and 3 Heermann’s Gulls on the Point Orient Pier were my first of fall
for the county. Also yesterday, the summering Horned Grebe in the
Richmond Marina first found by Roger Kohn on June 12th continued.
July 27th, a rare in the county Ruddy Turnstone was at Meeker Slough
with Black-bellied Plovers.
July 23rd was the arrival date for my Contra Costa first of fall Black
Turnstone, with 9 at Meeker Slough and 3 at the Dotson Family Marsh.
On the same date, 3 summering Lesser Scaup were observed at Pt.
Isabel, separate from the summering flock of Greater Scaup.
And as of a couple days ago, the summering Costa’s Hummingbird
continues in Alamo.