Written by Peter Pearsall/Photo by Peter Pearsall
As summer draws to a close, the relentless heat of Oregon’s high desert slowly abates—a difference most keenly felt in the increasingly chilly mornings and evenings. It’s this gradual drop in temperature, along with the shortened photoperiod (length of day), that clues organisms in to winter’s coming. It’s time to migrate, hibernate, drop excess foliage, or otherwise hunker down to endure the chill.
Birds, like many aspects of the landscape, change in lockstep with the seasons. Some of the species found at Malheur Refuge are year-round residents, but the majority pass through on their way to other areas, using the refuge as a stopover site. This is especially true of Malheur’s shorebirds.
Malheur Refuge is an oasis in the high desert of southeast Oregon, attracting up to 25 million migratory birds each year. Tens of thousands of these migrants are shorebirds. Twenty-seven shorebird species use the Refuge at various points throughout the year, including Western sandpipers, long-billed dowitchers, Wilson’s pharalopes, Wilson’s snipe and American avocets.
The fall migration of shorebirds is typically well underway by September—some species may have started as early as June. As the naturalist Kenn Kaufman has noted, “Most of our migratory shorebirds nest in the Arctic, where the breeding season is quite short, which helps to explain their early southward movement. Some may head south in June if their first attempt at nesting fails, because there may not be time, in the brief Arctic summer, for a second attempt. In a number of species, one member of the pair will leave before the young are full-grown (or even before the eggs hatch), leaving the other parent to finish raising them…[In many cases], juveniles of most shorebird species migrate later than adults.”
Here’s a selection of migratory shorebird species found at Malheur:
Wilson’s phalaropes are dainty, eccentric shorebirds that congregate on Malheur’s shallow lakes and ponds by the thousands during migration. Unlike other phalarope species—which nest in the Arctic and spend much of their time wintering on the open ocean—Wilson’s phalaropes breed in North America’s interior and winter in South America. This species regularly nests on the Refuge. Phalaropes typically feed while afloat, frenetically kicking their legs to bring particles to the surface—a technique that incidentally causes the bird to spin like a top. All phalaropes are sexually dimorphic but in an unexpected way: females are larger and more brightly plumaged than males; females compete heatedly for mates; and males do all the nest-building and brooding.
North America’s largest shorebird, the Long-billed curlew breeds in arid grasslands of the West and winters along the southwestern coasts into Mexico. Curlews are commonly seen far from shorelines, stalking prairies and other open areas in search of invertebrates.
It’s no wonder where the first part of this shorebird’s name comes from: The curlew’s thin, decurved bill can be more than eight inches long—about a third of the body length of an adult, and one of the longest bills of any shorebird. It uses this ungainly implement to pluck prey items from its path or extract them from burrows. The second part of the name—curlew—is a rendering of the bird’s repetitive call: “Cur-LEE! Cur-LEE!”
Long-billed Curlews were once more widespread across the Great Plains and Great Basin regions of North America, but much of their prime breeding habitat has been lost to agricultural development. It’s estimated that just one percent of America’s native prairies remains—a mosaic of short- and tall-grass habitats that support a wide variety of bird, mammal, invertebrate and plant species.
Western sandpipers breed in northwest Alaska and Eastern Siberia, spending winters along both coasts of the Americas. Their twice-yearly migrations tend to occur in stages, rather than the marathon non-stop flights undertaken by some species. But no matter how many pit-stops are taken along the way, it is a considerable journey by any measure, particularly for a one-ounce shorebird.
During spring and fall migration, Western sandpipers are usually the most numerous shorebird found at Malheur Refuge. Thousands of these pint-sized sandpipers can be seen carpeting the exposed mudflats along the Refuge’s lakes and ponds, fueling up for the journey ahead.
The American avocet is a big, gracile, leggy shorebird with a distinctly upturned bill, commonly breeding throughout the continent’s interior and spending winters in Baja, Central America and along the Gulf and Atlantic coasts.
When engaged in its most characteristic feeding behavior, the avocet wades purposefully near the shore, its sickle-shaped bill held inches below the water’s surface in a rhythmic coursing. Sweeping side-to-side through the murk as a reaper might wield its scythe, the avocet apprehends its invertebrate prey more often by touch, not sight. When the avocet happens upon a lively morsel, up snaps the bill and the prey is lifted from the water and quickly swallowed.
Due to a range of factors, from habitat loss or degradation at wintering and breeding grounds, to delayed prey abundance as a result of climate change, shorebird populations across the continent have declined by an average of 70% since 1973. Species that breed in the Arctic are among the hardest hit.
That’s one of the reasons why Refuges like Malheur are so important—they provide reliable resting, breeding and nesting habitat for hundreds of migratory bird species and other wildlife. With more than 95 percent of wetland habitat along the Pacific Flyway now lost to development, the Refuge offers a crucial stopover site for shorebirds on their globe-spanning peregrinations.