Author: Anne White | Published: August 15, 2023 | Category: Species Spotlight
This article originally appeared in The Source on August 9, 2023.
What is the future for the American avocet? Even this common species faces an uncertain prospect in Oregon’s high desert
“Its large size and conspicuous colors could hardly be overlooked, even if it were shy and retiring,” wrote renowned ornithologist Arthur C. Bent in “Life Histories of North American Shorebirds.” The American avocet (Recurvirostra americana) is one of the most distinctive shorebirds in the Great Basin. Known as waders in the avocet and stilt family, they spend much of their time foraging in shallow water or on mud flats, sweeping their bills in water to seek prey. While it might sound like quite the life by the shore, populations of American avocet across the West have declined as a host of factors threaten the high desert oases they call home.
Habitat, Breeding and Migration
American avocet, a species that ranges throughout the central and western U.S., are one of the most common shorebirds in the northwestern Great Basin, an arid region between the Sierra Nevada and the Rocky Mountains that includes the eastern portion of Oregon. They frequent shallow fresh and saltwater habitats such as wetlands, saline lakes and ponds. In Oregon, you’ll commonly see them in places like the Malheur National Wildlife Refuge, Summer Lake Wildlife Area, Goose Lake, the Klamath Basin, Warner Wetlands and Lake Abert.
Life for the avocet centers around breeding and migration. Wintering in southern California and Mexico, avocets migrate north in the spring to breed across the Great Basin. During breeding season, the species is easily identified by their long grey-blue legs and rust-colored head and neck, which are replaced by white feathers after molting. Males and females are nearly indistinguishable except for the curvature of their bill; males have a straighter bill while the females tend to curve upward. These differing beak structures provide unique advantages when foraging for food. With their straighter bill, males are more adept at probing the water column to feed. Females will sweep their bill from side to side — called scything — while wading to strain invertebrates from the water.
Although most avocets don’t breed at Oregon’s Lake Abert, in August and September birds flock to the lake to gorge on the abundant alkali fly and brine shrimp populations. As many as 40,000 avocets have been counted in a single day at Lake Abert, the highest abundance of anywhere in Oregon. Higher counts of avocets have only been recorded at the Great Salt Lake and Lahontan Wetlands, illustrating the importance of Lake Abert to avocet populations.