San Francisco Bay is the largest estuary on the west coast of the United States. Its 30,000 acres of wetlands, open water, and upland habitats are home to at least 800,000 birds at any given time and to millions during peak migration1.

San Francisco Bay National WIldlife Refuge ComplexDon Edwards San Francisco National Wildlife Refuge was the first urban National Wildlife Refuge established in the United States and is dedicated to preserving and enhancing wildlife habitat, protecting migratory birds, protecting threatened and endangered species, and providing opportunities for wildlife-oriented recreation and nature study for the surrounding communities.

The refuge provides habitat for nine species of Federally-listed threatened or endangered species and is home to 227 species of birds, including 8 percent of the world population of the Western Snowy Plover. It protects 60 percent of the world’s population of California Clapper Rail, as well as a substantial number of Salt Marsh Harvest Mouse, both found only in the remaining tidal marshes of San Francisco Bay2.

This is a huge refuge comprising 30,000 acres of the 43,000 acres authorized by Congress already acquired. With over 30 miles of hiking trails and diverse habitats including open bay, salt ponds, salt marsh, mudflats, upland and vernal pools, stopping at the visitor center or planning your visit ahead of time is crucial to maximize your Don Edwards San Francisco Bay National Wildlife Refuge experience.

The Visitor Center is open Tuesday through Sunday from 10 a.m. until 5 p.m. and is closed on all national holidays. Located at 2 Marshlands Road in Fremont, the center overlooks La Riviere Marsh, a restored salt marsh which is home to two endangered species, the California Clapper Rail and Salt Marsh Harvest Mouse.  As a matter of fact, the trail through La Riviere Marsh begins just beyond the visitor center.

La Riviere Marsh TrailHeading down the wooden stairway you are able to witness the expanse of this salt marsh habitat that was once a crystallizer pond in the old salt making days. Click on photos for full sized images.

La Riviere MarshThis boardwalk leads across the marsh to a levee. As I began walking across the marsh, I was entertained by a pair of Greater Yellowlegs (Tringa melanoleuca) that appeared to be exhibiting pairing behavior. Chasing one another, vocalizing and getting plenty of exercise which went on for quite some time.

Greater YellowlegsAccording to the trail information sheet, when you reach the levee, turn right and look for the endangered Clapper Rail in the channel to your right. Of course, that was one of my main target species but I dipped on the elusive rail. Apparently, it may be seen in the muddy slough channels in this area during low tide. An excellent reason to plan your trip and check the tide tables for the optimum time to see certain species.

A Great Egret (Ardea alba) put on a show of fishing prowess and also looked rather dapper amongst the California Poppies.

Great EgretI followed the levee back toward the other end of the trail at Marshlands Road and spotted an Alameda Song Sparrow (Melospiza melodia pusillula) on the way, which is a species of special concern in California. They are permanent residents of the salt marshes bordering the south arm of the San Francisco Bay. A subspecies I didn’t even know about until writing this report 😉

Alameda Song Sparrow

There was also a pair of American Wigeon (Anas americana) in the channel, the drake showing off for his mate.

American Wigeon Drake

This is the view from the other end of the La Riviere Marsh Trail, looking back toward the visitor center.

LaRiviere Marsh EntranceI decided to head back toward the highway entrance to the park on Marshland Road as I spotted some other shorebirds of interest when I drove in. This was taken looking back at the visitor center from a spot along a levee closer to Thornton Road. You can see a map of the trails around the visitor center here.

LaRiviere MarshThere were good looks at Willets (Tringa semipalmata) in the small ponds along the roadside and a California Ground Squirrel (Otospermophilus beecheyi) atop the levee.

Willet

California Ground SquirrelThere were also plenty of good views of  Greater Yellowlegs

Greater Yellowlegsand a young (note greenish legs) Snowy Egret (Ardea alba) foraging…

Snowy Egretwhile an adult takes flight from the muddy channel.

Snowy EgretThere is so much to see at Don Edwards San Francisco Bay National Wildlife Refuge, I had to split this report into three separate posts. Next time we will head out the Tidelands Trail and Newark Slough.

Be sure to watch the informative video of the San Francisco Bay National Wildlife Complex at the top of the sidebar giving you an overview of the seven National Wildlife Refuges that make up this incredible treasure of wildlife habitat in California.

If you haven’t already done so, please click on the Facebook widget in the side bar and “Like Us” on Facebook, and if you are interested in showing support for our project, check out the “About Us” page, send us your information and we’ll add you to the page! Also tell your friends about the Wildlife Conservation Stamp project and help us spread the word!

References: 1Don Edwards San Francisco National Wildlife Bird List, 2U.S. Fish & Wildlife Service

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