Field Journal – Shorebird Marsh/Marta’s Marsh

Date and Location:

11/15/23 – Shorebird Marsh overlook/Marta’s Marsh, Marin County, CA

Site Description and Conditions:

Cloudy and cool; variable breeze. We stopped at two locations along this trip, starting with the Shorebird Marsh overlook…Flat, shallow waters with some tiny and sandy “beach-like” areas mixed in with some small shrubs in the vicinity. Sweeping views of the water and ample views beyond Corte Madera Marsh. The second location was quite similar, with a trail leading deeper into the water near Corte Madera Marsh (Marta’s Marsh); these waters were more expansive with less beachy areas around.

Narrative:

At our first location, we observed a variety of shorebird species with numerous individuals each; hundreds of Dunlin, American Avocet, Least Sandpiper were seen along with large populations (in the dozens each) of the Northern Shoveler, American Widgeon, Green-winged Teal, Gadwall, Black-bellied Plover, and Black-necked Stilt. Many of these were seen for the first time, but many exhibited similar feeding and group behavior. At our second location, we came across significant numbers of the Green-winged Teal, Long-billed Dowitcher, European Starling, and a huge group of the House Finch. We saw some new rails and stilts as well, including the Black-necked Stilt, Ridgway’s Rail, along with some egrets and herons. Notably, we also witnessed a few Starlings under attack by a Peregrine Falcon and a Sharp-shinned Hawk attempting to prey upon a meadowlark. Quite an active trip with a tremendous number of species, many of which were new.

Species Account: American Avocet – Recurvirostra americana

A beautiful shorebird with an upturned bill (twice as long as its head) and distinctive feeding pattern, 16-20 inches in length, digging its bill into the water in a sweeping back-and-forth motion, found in groups as we saw on our route, into the hundreds in some cases along shallow waterfronts and wetlands. Pictured is the non-breeding adult; breeding adults have an orange wash from the neck up. Notably, Avocets exhibit anti-predatory behavior, building nests in usually inaccessible areas…when predators do approach, several individuals work to distract the predator.

Home Time – Thanksgiving, Chain of Lakes to SF Botanical Garden

For this week’s extended birding session I spent time in GGP, starting with the Chain of Lakes and North Lake, a location I frequented before. This time there were quite a few racoons along North Lake, completely comfortable with human presence; assuming they were preparing for the winter season. Many of the same ducks and species seen on the first occasion were seen again…other birders were also here as in the first trip. Very friendly Mallards and American Coots were found here, along with some Cormorants perched on some wood. Once again, a beautiful Red-shouldered Hawk flew overhead (quite a few this month when out birding) along with multiple Sharpies and a pair of Cooper’s Hawks. Along the trail south, Merlin picked up a Barn Owl, but I was unable to make it out with my binos or my nearsighted eyes. The walk yielded many common species already seen, including multiple warblers including the Orange-crowned, Yellow-rumped and Townsend’s. Upon entering the Botanical Garden I was greeted with MY FAVORITE Canada Geese (about a dozen) before seeing other common perching birds, including the Pacific Wren, a Red-winged Blackbird, and another Red-shouldered flying overhead, loud as ever.

https://ebird.org/checklist/S156154217

Merlin Meditation – Chain of Lakes, SF Botanical Garden

During this trip I made sure to stay as quiet as possible around North Lake; cars on the other side made it difficult to use Merlin to identify birds but it was able to pick up a Barn Owl. I stayed in the area and along the trail to see what I could pick up; the app did a very good job with birds at lower heights, but was unable to pick up calls from the taller trees due to ambient noise. Nonetheless, I picked up most of the birds that I was able to visualize, including the warblers listed. The Red-shouldered Hawk, identified with Merlin, has a very distinct and loud resonant call.