The most recent addition to the Chico Basin Ranch Bird Checklist is Red Phalarope (Phalaropus fulicaria). There are only three phalarope, or shorebird, species in the world and now all three have been recorded on Chico Basin Ranch. The word phalarope is a combination of Greek words meaning ‘coot-footed’ referring to the three lobes of the semi-palmated feet.
Red Phalaropes are most often found in offshore waters in migration and two of the phalaropes are the only true oceanic shorebirds but they are at home in the sea or on land. Red Phalaropes have salt glands and a layer of down that traps air making it very buoyant. As such they are well adapted to marine environments. Because this bird was born this summer in the high arctic tundra it hasn’t migrated before this fall and a careful examination of it feathers shows it is molting to its basic or winter plumage (gray back feathers). On Chico I found it feeding on aquatic insects on, and just below, the water surface on a tiny pool resulting from the overflow of a stock tank.
Like all phalarope species, Red Phalaropes have reversed sexual dimorphism meaning it is the male who incubates the eggs and cares for the young. In breeding plumage (below), the female is bright rufous with a contrasting white cheek and quite a beautiful bird. The bright female has a high level of a male hormone and might be the reason she is more aggressive than the male. They nest in the tundra above the Arctic Circle in the U.S., Canada, Iceland, and Russia. In winter they are found offshore in southern South America and southern Africa.
When in offshore waters, Red Phalaropes feed on plankton in the same waters where whales are found. As a result, historically whalers looked for flocks of Red Phalaropes often indicating whales were nearby. Unfortunately, the increased amounts of decaying plastics floating on the ocean’s surface are being ingested by Red Phalaropes and perhaps adversely affecting their population.
Here a photograph of a female Red Phalarope in breeding plumage feeding on tadpole shrimp in a tiny pond on Pawnee National Grasslands in northern Colorado on June 5, 2007 on her way north. Compare the two plumages.
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