I have been birding a bit while on essential outings recently. Here are some notes, reverse chronologically:
But, first, a word of caution! Cassin's Vireos start to trickle back into the Diablo Range the last few days of March and the first few of April, and it is not unusual to have a few singing on Diablo by now. But, if you hear what you think is a Cassin's Vireo, make sure it isn't a Purple Finch, which make similar question/answer calls! If you are unsure, track it down, or at least take audio. Many are unaware of this Purple Finch vocalization and Cassin's Vireos can be overreported during this time because of this. Anyway...
Today (4/4) on Bethel + Jersey Islands: Arrived at Piper Slough around 620 to watch dawn flyout from the delta, and regretted not arriving 10 minutes earlier. The flyout was great for late season numbers with 2000 White-fronts and 400 white geese (I only picked out 2 Ross's). 386 Bonaparte's Gulls, most in alternate plumage, flew E to W down the slough. One bittern thunder pumped from the reedy median before sunrise, and then left, sometime between 645-655. My first bittern at Bethel! The flight was almost completely finished by 7. Not flight related, but similarly noteworthy, were two Purple Finch at the E end of Piper, quite rare in the delta, and 2 Blue-winged Teal in the traditionally flooded field on Bethel Is. Rd. Jersey Island was disappointing with only 2-3 flooded fields, too deep for anything save a handful of dowitchers and a Greater Yellowlegs. Then I was off to Merced to get out of the rain...
4/2 I checked a few spots on the bayshore for rockpipers, specifically Ruddy Turnstone. Found none (of course). The tide was at 0 feet and created mudflat on the S side of Vincent Park which held about 200 shorebirds--not bad! The Black Scoters were gone, as far as I could tell, and there was a White-fronted Goose on the marina's North side. An afternoon visit to Point San Pablo yielded a rather late Say's Phoebe at signal hill, singing--they don't breed away from the Diablo Range in Contra Costa--and 3 male Rufous Hummingbirds. Overall a yield of 5 migrant/returning warblers, 3 Orange-crowned, 1 Wilson's, and one Townsend's, a bit disappointing.
3/31 no Ruddy Turnstones again anywhere from Hercules to El Cerrito. No Surfbirds either at Hercules Point, which was a regular roosting site only a couple years ago, although it may be too late in the season. At Point Isabel, a tide of 0 feet provided foraging habitat for about 2000 shorebirds, but there was nothing extraordinary among them. Almost 100 ea. of Semip, and b.b. plover, 45 dow, 1000 peeps, 800 dunlin. Generally these mudflats are only visible on tides between 0-2.5 feet, so timing a visit here with the tides is crucial. The Willows just S of Garrity Creek Mouth in Pinole had ~70 Yellow-rumped Warblers, including 6 Myrtle and 3 Audubon/Myrtle hybrids! This is up from a total of 0 Yellow-rumped Warblers in February at this location. I'm hoping this large-ish, easily accessible willow patch will be lucrative for migrants in the fall.
Still 3/31, in the Diablo Range, a Warbling Vireo was back along Morgan Territory Road, and a handful of selas. (presumably Rufous) were moving through. Besides that, not much migrant activity. And many thanks to Derek Heins for finding me my county Black Rail at Dow Wetlands Preserve! It wasn't very loud in the wind, but it was there. (It also looks like Grackles might nest this year at Dow. I am unsure if they have nested here in the past, but they are certainly expanding East.)
I don't write about my yard a lot, but the past couple of days I have had up to 10 Rufous Hummingbirds and down to a low of 6 (6 isn't very low). Every day we have had 10-15 selasphorus, and I have been experiencing the pain of sorting through them all. Earlier in the week, most were males so it was easy to count Rufous v Allen's v unIDed selasphorus (10:1:4) but now we have more females, and my life has become more difficult. Either way, this seems to be a good season for Rufous Hummingbirds, at least in Central Contra Costa. Excited to see how many will be at Mitchell!