Wednesday, August 14, 2013

Roselaari Red Knot


Aside from the confiding rockpipers, I also recently had the pleasure of coming nose to nares with an adult Red Knot, largely still in alternate plumage. Red Knots are uncommon migrants and winter visitors to California, and fate has decided that they frequently favor sites where they are difficult to see from very close range. This bird had something entirely different in mind though, joining the flock of rockpipers that were slaughtering mole crabs on a Ventura beach. At times I had difficulty keeping the chunky bird in the frame...a nice problem to have for a change. It was a bit too much for me though...as I walked back to my car, my knees buckled and I wept openly next to a rotting sea lion carcass. It was a low moment...but I've had far worse.


The Red Knots on the west coast of North America are classified as Calidris canutus roselaari, the world's largest subspecies of Red Knot (gasp!). The famous Red Knots of the east coast are C. c. rufa, which migrate between the Canadian Arctic and spend their winters in Argentina and Chile. C. c. roselaari breeds in Alaska and Wrangel Island (Russia), and winter primarily on the west coast of Mexico, with some birds spending the winter north in California. Some sources suggest a drastically different winter range that includes sites on the Atlantic coast (birds that winter in the southeastern U.S. have a different molt schedule from the birds that go to South America), but a variety of data from recent years strongly suggests C. c. roselaari is confined to the Pacific side of the continent.





Like C. c. rufaC. c. roselaari knots are long-distance migrants, and are thought to be able to cover large distances in single flights. Oregon, for example, does not have any sites at all that are known to concentrate these species, which makes me grateful that I don't have the misfortune of dwelling in that knot-foresaken state. It is likely that many birds that stage in Gray's Harbor, Washington, skip Oregon completely as they head south to the fertile shorebirding grounds of California and Mexico. In California, they appear to be largely dependent on large tidal bays and estuaries, such as San Diego Bay, San Francisco Bay, Humboldt Bay and Point Mugu.




The U.S. Fish and Wildlife Service (USFWS) estimated C. c. roselaari to have an entire population of <10,000 individuals in 2008, which is really not much. A number of organizations petitioned to list C. c. roselaari under the Endangered Species Act several years ago, but USFWS declined to do so since there was no evidence of a population decline. The west coast knots do have a number of important stopover sites, but their food sources in these places appear to be relatively healthy, unlike the horseshoe crab population C. c. rufa is so dependent on.  By USFWS's own assessment, C. c. rufa does appear to be on track to get the protection it deserves (which will, in turn, protect/benefit the entire Delaware Bay horseshoe crab fishery, many other bird species, marine life, etc.), but who knows about what politics may come into play to prevent that action.




A knot in breeding plumage does not blend in well with other shorebirds. Sandpipers and rockpipers alike are frequently seen standing awkwardly in awe at the crippling plumage of their pudgy cousin, pupils dilated and unsteady on their feet.



May you all meet many knots this fall. Much of today's information on C. c. roselaari was plucked from the USFWS.

4 comments:

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    1. Your state is good enough for them to shit on...but that's about it.

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  2. Ready or Knot...we're going to turn one up in Phoenix this August, or die trying!

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    Replies
    1. I highly recommend it. They are regular at the Salton Sea, so its not like they never fly inland.

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