Tuesday, September 23, 2014

Juvenile Wilson's Phalarope at San Luis Rey River Mouth

Wilson's Phalarope
Wilson's Phalarope. San Luis Rey River mouth, Oceanside, California. September 7, 2014. Greg Gillson.
Of the over 200 species of shorebirds in the world, the three species called phalaropes are the only ones that are usually found swimming. The Red Phalaropes and Red-necked Phalaropes breed on the Arctic tundra in both the Old and New World, and migrate south in fall to spend the winter far at sea in tropical oceans. The Wilson's Phalarope is more of a landlubber, breeding in prairie potholes in western Canada and the United States and wintering primarily at inland ponds in western and southern South America.

Most shorebirds have unwebbed feet. Some shorebirds, however, have partial webs between their toes. The phalaropes are unique among shorebirds in being lobate--having flaps or lobes that aid in swimming, much as the feet of grebes and coot.
Lobate: http://commons.wikimedia.org/wiki/File:Foot_of_phalarope_%28Anton_Reichenow_1913%29.jpg
Phalaropes also reverse their sexual roles. Females are larger and more brightly-colored than males. The females pursue the males and fight off other females from their mate. As with many shorebirds, the males take all the work of raising the young--incubation and chick care. Vocabulary word for the day: Serial Polyandry: females take multiple mates, one after the other, abandoning their mate after they lay eggs.

As with many shorebirds, phalaropes have a bright breeding plumage, a gray winter plumage, and the young have a long-held juvenile plumage they keep through the fall into winter.

For a photo I took of a bright female in breeding plumage in Oregon in 2010, see my Pacific NW Birder blog post: "Memorial Day weekend at Malheur: Part 9."