Knot your average flight
You’ve probably seen different shorebirds flit short distances here and there on the beach, walk the mudflat probing unceasingly or do their funny little dance up and down the beach just at the wave’s edge. There are a lot of different species, most relatively small and most not overly flamboyant.
Now imagine a flock of shorebirds taking off from southern Brazil for a seemingly non-stop, 6-day flight to their first layover in North Carolina. That’s about a 5000 mile trip – an average of 35 miles per hour, for 144 hours. Red knots (Calidris canutus rufa – pictures) do this year in and year out, many flying a distance farther than the Earth to the Moon during their lifetime.
If we were to take a trip to southern Brazil, it would probably be an 8 or 10 hour flight. We would have been fed two meals and had a several drinks. We’d still be tired and a little cranky, but thrilled to hear the pilot put down the landing gear. A red knot would probably have knotted muscles or a knot in its stomach, but would surely share the thrill of the landing…
Maybe knot a thrill, but that moment of seeing the coast emerge from the Atlantic blue means likely survival. These birds weigh less than 1/2 pound when well fed. They arrive at their eastern US feeding grounds sometimes less than half that weight! Their little bird brain and emaciated body must be dreaming of horseshoe crab eggs. The forage for which their flight is perfectly timed. Red knots typically forage on shellfish spat, but the high energy horseshoe crab eggs allow them to really pack the ounces back on before heading to their arctic breeding grounds.
Not sure why a bird would subject itself to such a tortuous migration (maybe it brags to the other subspecies of red knot who opt for slightly shorter distances). Still, it is a great example of how critical certain marine shoreline habitats can be and how complex the relationship can be between multiple species, habitat, water quality, environmental conditions and global human communities.
The population of the birds that travel to Argentina dropped by more than half between the mid-1980’s and early 2000’s. International efforts are underway to conserve these travelers and this remarkable life history that connects people from the entire Western hemisphere.
The subspecies Calidris canutus roselaari migrates down the West coast from the Alaska’s north coast. Apparently they aren’t many of them, but you might have a chance of seeing them on the outer coast in the spring.
I’ve included a few links below if you’re interested in more info… Here’s to a lifestyle that does knot require me to lose and gain 100 pounds every year! JEff
Red Knot – The Birds of North America
Online
US Fish and Wildlife Service – Red Knot factsheet
(pdf)
Red Knot – An Imperiled Migratory Shorebird in New
Jersey (amazing before/after photos of weight gain in Delaware
Bay)
Shorebird Researchers Document Red Knot’s Record-breaking
Flight
Jeff Adams is a Washington Sea Grant Marine Water Quality Specialist, affiliated with the University of Washington’s College of the Environment, and based in Bremerton. You can follow his Sea-life blog, email to jaws@uw.edu or call at 360-337-4619.
