San Diego River, California - 7 tern day - 29th June 2007

Published by Martin Birch (martinandtiffany AT aol.com)

Participants: Martin Birch

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At the end of June 2007 I managed to squeeze out a morning from a family holiday to bird the San Diego river mouth. This is a fantastic area that with more time would have surely yielded up more species, but even with just a few hours left a Brit birder delighted with the range of birdlife on the edge of a major US city. Although the river at this point is funnelled through a concrete culvert, the low water level had exposed a number of sand bars and marshy areas which offered up a variety of interesting habitats that were being enjoyed by good numbers of egrets, herons, waders, terns and hirundines.



San Diego River - from Google earth. The river travels 52 miles from its headwaters to the Pacific Ocean where it discharges near the entrance to Mission Bay.

I started birding at the Mission Bay Drive bridge and over the next couple of hours slowly walked towards the river mouth a couple of miles downstream. At the Mission Bay Drive bridge a number of Black-crowned Night Herons were feeding along the water’s edge with a couple of Little Blue Herons. As I walked further downstream, good numbers of Snowy and Great Egrets were feeding under the Sunset Cliffs Boulevard bridge. At this point a few Least and Forster Terns were flying back and forth along the river.

South of the Sunset Cliffs Boulevard bridge and the birdlife really started to pick up. At this point sand bars were exposed that held a good range of wading species with Short-billed Dowitchers and Willets being the most numerous. Scanning through the birds produced a small group of ‘peeps’ with both Western and Least Sandpipers represented. On the sand-bar itself the tern flock held both Elegant and Royal Terns (very easy to separate when you see them together) along with Caspian Terns and two unexpected Gull-billed Terns. Scanning the sand bar also produced two Black Skimmers which really made the holiday! Counting the skimmers, this was a seven tern day!

 Elegant Tern
Elegant Terns, California © Andy Birch

 Elegant Tern
Elegant Terns, California © Andy Birch

 Royal Tern
Royal Terns, California, © Brian Michael Ivon Jones

Further along there was an area of fenced-off sand dune and maquis which held Horned Lark, Say’s Phoebe and good numbers of sparrows. Those that came near enough to the perimeter fence to allow identification were Savannah Sparrows.

For some great images of the birdlife of the San Diego River Channel have a look at Neil Solomon's gallery at http://www.nsolomonphoto.com/San%20Diego%20River%20Channel/index.htm

Species Lists

Great Egret (15+)
Snowy Egret (100+)
Little Blue Heron (4)
Night Heron (3)
Great Blue Heron (20+)
Gull-billed Tern (3)
Elegant Tern (10+)
Royal Tern (3)
Least Tern (8+)
Forster’s Tern (10+)
Caspian Tern (15+)
Black Skimmer (3)
Killdeer (6)
Grey Plover (3)
Least Sandpiper(3)
Western Sandpiper(2)
Ruddy Turnstone (5)
Short-billed Dowitcher (40+)
Willet (20+)
Marbled Godwit (4)
Whimbrel (3)
Long-billed Curlew (4)
Barn Swallow (4)
Northern Rough-winged Swallow (4)
Cliff Swallow (6+)
Say’s Phoebe (1)
Horned Lark (6)
Brewer’s Blackbird (1)
Savannah Sparrow (4)
Red-crowned Parrot (2)

San Diego River south of Mission Bay, copyright Philip Erdelsky
San Diego River south of Mission Bay, copyright Philip Erdelsky


San Diego River, looking upstream, copyright Philip Erdelsky
San Diego River, looking upstream, copyright Philip Erdelsky


Mouth of San Diego River, copyright Philip Erdelsky
Mouth of San Diego River, copyright Philip Erdelsky


Thanks to Philip Erdelsky for use of images of the river mouth and to the surfbirds photo library for images of Elegant and Royal Terns.

For more information on San Diego river visit http://www.sandiegoriver.org/