Mandy and I went to visit our sons in San Francisco and to enjoy our two beautiful grandchildren. On a whim we traveled south to look for shorebirds. San Francisco Bay has long been known to be important to thousands of shorebirds because of the good work of Gary Page and Catherine Hickey of Point Reyes Bird Observatory and Nils Warnock formerly of the Observatory. Prior to our visit I sought their advise on the possibility of finding red knots. The west coast knot (Calidris canutus rosalarii) is a different subspecies than our east coast knots (C. canutus rufa). The status of the west coast knot is more poorly known because flyway-wide field work has only started in the last few years.
Big questions loom. In 2006, Guy Morrison led a team assessing the number of all shorebirds in North America and they found the current population of rosalarii to number 20,000 birds, less than 20% of an earlier estimate made in 2000 by the same team. Why the decrepancy? Does the difference represent a catastrophic decline, or was one or both of the population estimates wrong? The problem points to the difficulty and the attractiveness of working on shorebirds. If a birds breeds in your back yard and winters a short distance away, determining their numbers are not elusive. You may have any number of possible sources of information, Christmas Bird Count (National Audubon), Breeding Bird Survey and Breeding Bird Census (US Geological Survey), and Ebird (Cornell). But what happens when the breeding and wintering areas are poorly known, are thousands of miles from your home and potentially on opposite ends of the world?
Rosalarii red knots with black bellied plovers, short billed dowitchers, willets, marbled godwits and a lonely surfbird
But the puzzle of the west coast red knot goes further. On our coast (the US east coast) we have a very good idea of places where red knots and other shorebirds stopover to restore themselves. The Delaware Bay stands out from all the rest, but not far behind are the Mingan Archepelago in Quebec, Cape Cod, MA, Brigantine/Stone Harbor, NJ, Virginia Coastal Preserve (TNC), Cape Hatteras, NC, Cape Romain, SC, the Altamaha Delta in GA, and Jacksonville FL. These are just a few of the jewels in a necklace that stretches all the way to the southern tip of South America on the island of Tierra del Fuego. On the west coast, biologists know much about other shorebirds like the western sandpiper, but almost nothing is certain about red knots. Joe Buchanan has done good work on the coast of Washington and Roberto Carmona has done extensive work in Baja California in Mexico. Their work has given us much of what we know about west coast knots, but it provides only part of what we need to know. . . . . .
Like how important is the stopover in San Francisco Bay? Gary Page and his colleagues, Len Liu from Point Reyes and John Takekowa of the USGS, know that red knots use the Bay. How many is elusive, in some years it’s thousands, in other years hundreds. Is there a trend? Why do they use the Bay? Is it a brief stopover to restore lost reserves on their way south to wintering areas, do they stay for months to molt flight feathers and then move on, or are they wintering in the Bay? These are important differences as I have discussed here and there.
Map from Len Liu of the impoundments where red knots have been seen in the past.
Bay area on a USGS mapAll these questions need answers to help save the habitats that are important to red knots and other shorebirds. But what of the larger questions, how does San Francisco relate to other stopovers? Is it the only one in the California (which is nearly the size of the entire east coast) as the data suggest, or are there more stopovers? If knots don’t winter in San Francisco, then where do they go? Where do they breed? For a shorebird biologist these are an intrigueing lovely set of questions.
So Mandy and I went in search of knots and found 300 in a flock of 
Shorebird roost with San Mateo Bridge in the background and walkway on th5,000 willet, marbled godwit, dunlin, black-bellied plover and short billed dowitcher. We found this wonderful flock in the middle of a community along the shores of South Bay. The birds roosted along a seawall and a very-convenient walkway used by joggers, walkers, dog walkers, kids on bikes. It was a very improbable location. As usual, we found that some people walked off the path through the flock, and as usual we did our best to protect the birds. Mandy (with infinitely more patience than I) talked to one woman running her dog through the flock, and in the process flushing thousands of birds who were doing their best to rest on the high tide after a full day searching for food. Mandy asked the woman why she couldn’t use the walking path like all the others? She responded earnestly “my dog was only chasing the birds, he won’t catch them”. After explaining the impact of repeated disturbance, the woman gathered up her dog, thanked Mandy and walk away with a bit more appreciation.
Grandchildren, a new knotty problem – sounds like an invitation for new work.
Joseph, Tessa, Hank and Zoe Niles ( with thier grandparents)
