Date: 4/1/25 12:05 pm From: Dominik Mosur via groups.io <dominikmosur...> Subject: [EBB-Sightings] Some misc. observations from past several days 3/28-3/31/2025 (Alameda/Contra Costa Co.s)
Spent the past four days birding around San Ramon (Contra Costa) and Livermore (Alameda) and wanted to share some observations of migrants/breeding behavior I thought may be of interest to other birders in these counties.
Long-billed Curlews - a good sized flock (129) was noted in the fields at N. Livermore Ave. near the junction with Hartford Ave on 3/31
Whimbrels - (3) were with the Curlew flock 3/31
Golden Eagle - a nest in Last Trampas Regional WIlderness was noted once again occupied on 3/29. According to raptor biologists this nest (situated in a Blue Gum Eucalyptus) has been in use for "a number of years now"
Swainson's Hawk - a dark morph bird flying out of the eucalyptus row at N. Livermore just south of Manning Rd. 3/31 was a bit further west than the species is typically noted in the county
Cooper's Hawks - a pair was observed copulating near a nest located in the parking lot of a busy shopping center near "downtown" San Ramon, 3/28.
Western Kingbirds - these have arrived in numbers at known breeding areas around Highland Rd./N. Livermore Ave etc. (3) noted in Last Trampas Regional Wilderness 3/29 may breed in the area as well but likely on ranchland closed to the public (more visits required)
Warbling Vireo - one singing at the main staging/parking area at Las Trampas 3/29 was the first I've encountered locally. Many more should be on the way in upcoming days
Loggerhead Shrike - a bird appearing to carry food at the jct of Manning and Highland Rd.s 3/30 at the county line confirms breeding for this area. This is not an unusual confirmation date; shrikes are one of our earliest nesting passerines
Blue-gray Gnatcatchers - a healthy count (7) was noted along Trampas Ridge 3/29 where the species nests. A bird calling on top of Brushy Peak 3/31 was likely a migrant in that habitat
Grasshopper Sparrow - silent arrivals (2) were on Trampas Ridge 3/29, birds singing on territory noted along Marciel Rd. and in the grassland on east slope of Brushy Peak 3/31
Lark Sparrow - a bird was singing persistently along Marciel rd. 3/31
Dark-eyed Junco - a bird in juvenile plumage with fully grown out tail and no visible remnant of gape was a somewhat early fledgling (with a 12-14 d incubation and 10-12 d to fledge period this would indicate laying date possible in last days of February) , noted at Lake Annabel near the Bishop Ranch shopping center in San Ramon 3/28
Rufous-crowned Sparrow - this species is not uncommon on Trampas and Rocky Ridges in appropriate habitat, patches of Coastal Sage and rocky outcrops, but a pair in a large contiguous stand of Coyotebrush along Trampas ridge was in a somewhat unexpected location 3/29
Bullock's Oriole - recent arrivals in breeding habitat were noted at Las Trampas along Bollinger Creek 3/29, and (2) along a stretch of willow/Cottonwood riparian at the base of Brushy Peak 3/31, a bird singing during the downpour on top of Brushy Peak in sage amidst rocky outcrops and a few oaks may have been a migrant in that habitat
Tricolored Blackbirds -a flock (~30) mostly male birds flew over the Westside trail at Brushy Peak 3/30 was coming out of the direction of the Vasco Road Landfill. There is a big patch of Mustard visible there but unfortunately that area appears to be closed to the public. The Trikes were not noted the next day during a hike up to Brushy Peak.
Orange-crowned Warblers - dovetailing off the discussion on the list a few days ago, I tallied 30+ Orange-crowns during a 10 mile loop of Las Trampas Ridge and Bollinger Canyon Rd. 3/29. Orange-crowned Warblers are one of our earliest arriving migrants - often singing away on territory by the first week of March and sometimes in late February. A smaller number also winters locally.
Numbers of migrants should be picking up again starting this Friday 4/4 as a high pressure sets in for the weekend.
