Field Trips

Mt. Diablo Audubon Society (MDAS) is re-starting field trips this fall, after a year-and-a-half hiatus due to the COVID-19 pandemic. There are some changes from the way we used to do things, however. Firstly, there will be a sign-up process for each field trip, accessible on our website. By signing up, you will be acknowledging our Liability Waiver. Also, some of the trips may require limited-participation due to traffic/parking limitations. The sign-up process will allow us to manage this.

The biggest change to previous years is that, due to safety concerns brought about by the ongoing COVID-19 situation, MDAS will no longer organize or meet-up at staging areas for carpooling. Participants are encouraged to arrange their own carpools with people they are comfortable traveling with, but must expect to provide their own transportation to meet at the trip destination. This is the main reason why participation may be limited on some excursions. Some historical destinations will be abandoned for now as well due to traffic/parking considerations.

As usual, the field trips will be ranked according to difficulty:
Category 1: Easy, little or no walking, smooth paths.
Category 2: Moderate, 1 mile or more, possibly rough terrain.
Category 3: Difficult, extensive walking on rough terrain.

Please see the schedule and trip descriptions listed in the Upcoming Field Trips section of this page.

More Field Trip Destinations

In addition to the scheduled MDAS Field Trips, you may want to consider birding on your own at the following birding destinations.

Hayward Regional Shoreline, Hayward
This is a very popular location for walkers, fishing persons, and birders. Parking at the Winton Avenue parking lot is best at the first area before entering through the open gate. One can walk to the low, elevated mound known as “Mt. Trashmore.” Can you guess what is below the dirt and short grass vegetation? It is about a half-mile out to the edge of San Francisco Bay along the flood control channel. Going north past another landfill area brings one to a large, mostly dry mudflat known as “Frank’s Dump.” This can be shorebird heaven in late summer and fall, as they either gather for the winter or use the area as a stopping point during their southerly migration. One can see Willets, Marbled Godwits, Red Knots, Short-billed Dowitchers, Ruddy Turnstones, Black-bellied Plovers, and the occasional Pacific Golden-Plover. Migrant passerines may be seen in the trees and weedy areas near the parking lot; raptors can be anywhere.

Outer Point Reyes, Pt. Reyes
The Outer Point Reyes area is a wonderful place to find fall migrants, many of them Eastern passerine vagrants. The best places to check are the trees around the visitor center and monument at Drake’s Beach, the trees at the Mendoza Ranch, the trees at the Nunes Ranch, the trees around the residence at the Fish Docks, and the trees near the residence above the lighthouse. Some of the specialty migrants have included Blackburnian, Blackpoll, Chestnut-sided, Connecticut, Black-and-white, Magnolia, Prothonotary, Yellow-throated, and Black-throated Blue Warblers. We have seen Yellow-green, Red-eyed and White-eyed Vireos, Orchard Orioles, Ovenbirds, American Redstarts, Rose-breasted Grosbeaks, Peregrine Falcons, and Broad-winged Hawks. Look on the water for Common Murres, Pigeon Guillemots, Cormorants, and Loons. The chance to see migrants is very much dependent on the weather; the absence of winds from the northwest and an overcast night sky will help trap these land birds at the Outer Point. Be sure to check the National Park Service Point Reyes website for road closure information.

Hawk Hill, Marin Headlands
The fall southward migration of raptors can be quite spectacular if one is in a particularly good location. As birds fly south along the California coast, they eventually arrive at the Golden Gate, the one-mile wide opening to our bay. They don’t quite know what to do, as birds don’t like flying over the water. As a consequence, raptors congregate at what is now known as Hawk Hill above the Golden Gate Bridge, before finally making the jump across the gap. The Golden Gate Raptor Observatory conducts a count every fall of all the raptors. This year, the area where the counters stand is closed to the public, but anyone can stand nearby at Battery 129, where in normal times public demonstrations occur on Saturdays. Parking should be easier on a weekday. Before going, check the GGRO website.

Elsie Roemer Bird Sanctuary, Alameda
Editor’s Note: There is currently no entry into the Elsie Roemer Bird Sanctuary due to ongoing restoration work. Be sure to check the link above for the most up-to-date information.
This Alameda site is really good for shorebirds, as well as gulls, waders, and others. Our field trip would go one-and-a-half hours before a high tide. Our Chapter field trip would have been on Friday, October 16th, when the high tide would be 7 feet at 12:30 PM, the highest tide at a reasonable time for the month. High tides occur near the middle of the day on the 15th and on the 17th, but not quite as high as on Friday. Check a tide table before going to learn the best time to arrive. Parking is usually available along Shore Line Drive.

Abbotts Lagoon, Point Reyes National Seashore
We generally visit this location later in the month of October, but any time would be good. It requires driving to Point Reyes and turning onto Pierce Point Road. A 1-1/2 mile walk through the coastal habitat brings one to a bridge over the upper lagoon. Another 1/2 mile walk across sand and along the edge of the outer lagoon will bring one to the beach. A more rigorous 5,100 mile swim will take one to Japan. Birds we often see on this trip include sparrows, shorebirds, and raptors. The outer lagoon frequently has a good selection of shorebirds which will stay most of the winter. Snowy Plovers nest along the beach and south of the outer lagoon—they are often easy to find. American Pipit flocks need to be checked for possible Red-throated Pipits. Later in October we often have a good selection of raptors including Red-tailed and Ferruginous Hawks, Northern Harriers, and White-tailed Kites. Check the Point Reyes National Seashore website for access updates. While some Point Reyes sites are closed as of this writing, Abbotts Lagoon is open.

Bodega Bay
Not only is Bodega Bay famous for its role in the Hitchcock movie The Birds, but it is also famous for the many birds which can be found there. Starting in early fall and continuing through the winter, many shorebirds and waterfowl make Bodega Harbor their winter home. Any number of locations around the harbor can be visited for birding opportunities: The Tides Restaurant, Porto Bodega, the Rail Pond, Gaffney Point, Owl Canyon, Campbell Cove, and Bodega Head, among others. Currently, Lucas Wharf and Terrapin Creek restaurants are closed, but food is available at The Tides, the crab shack at the Spud Point Marina, and some items at Diekmann’s Store. A detailed description of bird-watching spots may be seen at this website.

Other bayside locations to try are:

Within Contra Costa County, you might try:

East Contra Costa County Birding Spots
Jerry Britten, MDAS President

Clifton Court Forebay
This is one of the most productive birding hotspots in the entire county, with over 200 species recorded on eBird. This can easily be an all-day birding expedition. During the fall, winter, and spring, thousands of gulls, scaup, and coots along with myriad other waterfowl are present here. During the summer months uncommon birds and rarities such as Western Sandpiper, White-faced Ibis, and Bank Swallow can be found. Good numbers of raptors are always present, including resident Bald Eagles. Great-horned Owls are often seen. Otters and even Sea Lions can frequently be observed. The parking area is at the end of Clifton Court Road off of Highway J4 a few miles southeast of Byron. It’s an out-and-back trip, as the paved levee road goes 90% of the way around the reservoir, leaving an open stretch of water between you and your car. Going to the end of this road and back is an approximately 16-mile roundtrip, so it is best explored with a bicycle, electric scooter, or other mode of transportation. A 5–6-mile roundtrip takes you to out to Eucalyptus Island, where there are large rookeries of Double-crested Cormorants, egrets, and herons in-season.  Out here are also good-quality dirt levee roads, connected to the paved road, that overlook very productive marshland, slough, and brush habitat along Italian Slough and Old River. The entire route is exposed with no shade, and can be windy at times.

Round Valley Regional Park
This 2191-acre preserve contains non-native grassland, oak woodland/savannah, shrubland, and riparian woodland plant communities. The park entrance is off of Marsh Creek Road between Deer Valley Road and Camino Diablo intersections.  The park has become very popular with local residents, so the large parking lot often fills up on weekends.  According to eBird, 145 species have been recorded here.  Typical woodland birds can be found, as well as grassland birds in the open valley that makes up a large fraction of the park.  Sometimes, large flocks of Long-billed Curlews forage in the valley during the fall and winter. The best birding is at the back of the park, along its southwestern edge that abuts Morgan Territory Regional Preserve and Los Vaqueros Watershed land.  This is about 3 miles from the trailhead, so a mountain-bike trip is a good way to explore it along the mostly-gently-sloping Miwok Trail.  Back in this area Lewis’s Woodpeckers have been reliable for several years.   As many as a dozen at one time have been recorded.  There are a couple of stock tanks in this area, which are good for loitering near to watch several species of birds come to take a drink.  The steep ridgeline at the park’s southwestern border was scorched, and, in some areas, burned to bare dirt by the August 2020 wildfires.  It will be interesting to see how this impacts local birdlife during the next several years.

Creekside Park (including Creek Road), Brentwood
This is the birding hotspot for fall, winter, and spring rarities in East County.  Several species are regularly seen here that are uncommon but findable farther west, but very scarce in East County.  Such birds include Golden-crowned Kinglets, Red-breasted Nuthatches, and Chestnut-backed Chickadees.   Often, scarce winter warblers such as Townsend’s, Black-throated Gray, and Orange-crowned are recorded.   Over-wintering Western Tanagers as well as vagrant Hammond’s Flycatchers, Red-naped Sapsuckers, and Scaly-breasted Munias have also been seen.  The southern terminus of the Marsh Creek Regional Trail begins at the trailhead at the intersection of Concord Ave. and Creek Road in south Brentwood.  A walk north from the trailhead up Creek Road along the riparian corridor of Marsh Creek is quite productive.  Less than ½ mile north of the trailhead, looking through a fence onto a golf-course pond can provide views of several waterfowl species.   A few yards north from here, there is usually water in the creek that many birds come to for bathing and drinking.   Continue along Creek Road, looking over the field to the left for raptors and other fly-bys.  Following this is a section of the road with a lot of toyon and other berry-bearing shrubs where Purple Finches, Cedar Waxwings, Hermit Thrushes, and other frugivorous birds can be found.  Past this, continue along Marsh Creek Trail over the pedestrian bridge spanning the canal, and enter Creekside Park. This park, especially the riparian habitat along the eastern edge, continues to be productive.  Continue along this edge of the park to its end at Crescent Drive.  In the fall and winter of 2020-2021, many observers saw the vagrant Plumbeous Vireo along this section.   This is about a 3 mile, flat, out-and-back roundtrip, and is the southern end of the Marsh Creek Regional Trail System that extends another 8-10 miles all the way to Big Break Regional Shoreline in Oakley.

Upcoming Field Trips

Jun 04

MDAS Field Trip — Outer Point Reyes

JUNE 4 @ 8:30 AM - 3:00 PM

Outer Point Reyes Saturday, June 4, 8:30 AM to 3 PM Leaders:  Hugh Harvey and Beth Branthaver This is a trip to see some spring birds, and visit some of the migrant traps.  We will stop at the lighthouse overlook and spend some time above the fish docks.  Bring water and lunch. Rating: Category 1 — […]

Inverness CA
Jun 11

MDAS Field Trip — Yuba Pass (2-day outing)

JUNE 11 @ 7:00 AM - JUNE 12 @ 1:00 PM

Yuba Pass Saturday-Sunday, June 11-12, 7 AM Saturday to 1 PM Sunday Leaders: Hugh and Rosita Harvey This is always a productive and well-favored weekend trip to the northern Sierra which requires driving and walking, some of it over rough terrain. Saturday we will bird in the Sierra Valley for basin birds.  Sunday we will […]

Calpine CA
Aug 20

MDAS Field Trip — Bodega Bay

AUGUST 20 @ 9:00 AM - 3:00 PM

Bodega Bay Saturday, August 20, 9 AM to 3 PM Leader:  Hugh Harvey, 925-935-2979 The last trip of our field trip calendar, but sometimes considered the first trip for fall birding.  At Bodega Bay are flocks of shorebirds including Black Oystercatcher, Wandering Tattler, Marbled Godwit, as well as tern, gulls, cormorants, near-shore pelagics and more.  […]

Bodega Bay CA
Oct 08

MDAS/SMD Field Trip—Curry Canyon

OCTOBER 8 @ 8:00 AM - 12:00 PM

Mount Diablo Audubon Society and Save Mount Diablo are partnering up for a hike on Save Mount Diablo’s gorgeous Curry Canyon Ranch. This portion of Curry Canyon Ranch showcases beautiful rangeland ecosystems and valley oak and riparian habitat. We’ll be looking for fall migrants, arriving wintering birds, and raptors. You might even see a golden […]