A Thousand Scaup

October 20, 2020

I was moving slowly northward on the east side of the park, looking at the glassy water of the North Basin, wondering what happened to the fall migration. Hadn’t seen birds in any numbers on the water since October 7. And then I saw them flying in. Wave after wave of them, coming from the north, splashing down. In half an hour, at least a thousand of them. The video above shows selected views of this throng, edited down to just over a minute. The video below is a panorama from one end of the raft to the other; if you should be inclined to want to count them, that’s your video. They were quite far away, nearer the east side of the North Basin than to me, so the images show limited detail. I’m guessing that these are Greater Scaup, not Lesser; the difference is in the curvature of the head, with the Greater being more rounded and the Lesser more peaked. If they move closer to the shore of the park I will get larger images for a firmer identification.

These birds have flown from northern Canada or Alaska. They breed in the Arctic tundra, a treeless region where the soil is permanently frozen deep. In the summer months, the top layer of soil melts and forms vast shallow ponds and marshes.

Vuntut National Park in Canada, showing tundra in summer. Photo by Wikipedia user Chris Kyrzyk.

These seasonal meltwaters make up breeding habitat for millions of birds and other creatures, including these Scaup. The tundra stretches around the pole, encompassing also Europe and Asia, and Scaup are active in all of its regions.

From northern Alaska to the Bay Area is about 2,500 miles. Despite the distance they have flown, these birds looked active and energetic. Many of them were diving. Scaup are great divers, foraging on the bottom for proteins and seaweed.