Surfbird Calidris virgate

by Frank Keim

With a sandpiper called Surfbird, you’re probably wondering why the name, especially since it only nests in mountain habitats. This is because during the non-nesting season, almost nine months a year, it can only be found in the noisy splash zones along rocky Pacific Ocean shorelines. During that period, it has one of the longest and narrowest winter ranges of any North American bird, and is found from warmer Alaskan coasts all the way south to the Strait of Magellan, Chile, a distance of nearly 11,000 miles. But also at this time, its range only extends inland for a few yards above the tide line.

In May, before heading north to nest in the highlands of the Y-K Delta and other mountainous areas in the Alaskan interior, the birds gather by the thousands in Prince William Sound to fatten up on the invertebrate life there, including barnacles, snails and bivalve mollusks. It was there, in fact, that the first Surfbird was collected and described by Western science during Captain James Cook’s 1778 voyage to Alaska.

Since the nesting habitat of Surfbirds is in dry rocky alpine tundra at higher elevations (500-6000 feet), there they feed mostly on insects and their eggs and larvae. Flies, crane flies, mosquitoes, beetles, bees, wasps, butterflies and moths are all on their menu. To catch their prey, they run along like plovers and gather them from the ground and plants, or pounce on them suddenly and pick them up in their bill.

Once they arrive on their breeding grounds in late May or early June, the males display in flight over their chosen breeding territory, flying with trembling wings 100 feet or more above the ground. Sometimes you may see them hovering in the wind as they sing to try to attract a possible admiring female below. As they descend, they often bow their wings stiffly downward. When a male actively courts a female, both birds may chase each other, then land together and stretch their wings skyward for a moment or two. Sometimes they may preen and feed each other, or even leapfrog over each other in a sort of fluttery flight. Surfbirds seem to be more sociable and less territorial than most other shorebird species, as evidenced by mated pairs that are often seen in flocks peacefully feeding together in the same area. It’s also reported that conflicts among males are almost unknown.

To prepare for nesting, the female scrapes a shallow depression on sloped ground and lines it with lichens, mountain avens and other flowering plants. She then lays four buff-colored eggs with dark reddish-brown spots, and both sexes incubate them for about three weeks. When the eggs hatch, the chicks are fully clothed in downy feathers with their eyes open, and able to feed themselves as soon as they leave their nest, which is almost immediately after hatching. When they’re strong enough they often accompany their parents to nearby coastal feeding areas such as mudflats to fatten up. Large family groups may gather there just before beginning their migration south in late July or early August. Then they will steadily make their way down the Pacific coastline until they reach their wintering habitat on the rocky outer coasts and islands as well as on stone jetties and breakwaters from the Alaskan panhandle to Tierra del Fuego.

Since the nesting grounds of the Surfbird are presently high up on mostly protected mountainous public lands, their numbers so far have remained fairly stable. However, the bird’s dependence on rocky shorelines in the winter makes it particularly vulnerable to oil spills. Also, the impacts of climate change, including rising sea levels, warming waters and resultant fewer food resources are worrisome for the conservation of the species into the future.

I’ve already mentioned the explanation for the bird’s common English name, but I was never able to find its Yup’ik name, possibly because of its nesting habitat so far from the summer travels of the Yup’ik people. Its scientific name Calidris virgata derives from the Ancient Greek kalidris, a term used by the early Greek philosopher-scientist Aristotle to describe gray-colored waterside birds; and the Latin virgata, meaning “striped.”