Interior Nesting Snowy Plovers at Malheur
Written by Teresa Wicks, Portland Audubon Society
Photos by Dan Streiffert, FOMR Volunteer
Western Snowy Plovers are well known for their coastal nesting population. Their sandy ocean adjacent nests are formed in small depressions (often called scrapes) in the sand. Our coastal nesting subspecies is listed as threatened both federally and statewide, due to population declines associated with habitat loss (largely due to beachfront home development) and disturbance associated with recreation.
The less discussed relative of the coastal nesting population is the interior nesting subspecies of Western Snowy Plover. This subspecies nests throughout the intermountain west, including at Malheur, primarily adjacent to saline lakes, springs, playas, and other shallow water bodies such as Summer Lake, Abert Lake, the Alvord playa, Malheur Lake, and throughout the playas of the Double O unit at Malheur National Wildlife Refuge. As water availability declines throughout the Intermountain West, largely associated with prolonged drought and overpumping of groundwater, habitat for our Interior Western Snowy Plover also declines.
To get a better understanding of water availability and Snowy Plover population status in Southeastern Oregon biologists conducted extensive Snowy Plover surveys in 2021. This was the first regional survey in approximately a decade. Snowy Plover numbers were concerningly low, potentially a signal of larger trends and potentially associated with low water levels. Because of this, in 2022 Portland Audubon worked with Malheur National Wildlife Refuge staff and Friends of Malheur to plan an extensive survey of Malheur springs and playas. In June, nine individuals, including Portland Audubon, Friends of Malheur NWR, and Refuge staff, and volunteers from Portland Audubon and Lane County Audubon hiked 40 miles, surveying all available habitat in the Double O. We found 36 Snowy Plovers total, down from 45 in 2021 and a steep decline from numbers in the 1980s and 1990s. For the first time since Portland Audubon and Refuge staff started re-surveying in 2018, surveyors found Snowy Plover chicks. This included one pair of approximately 1-week old chicks chasing brine flies along a Harney Lake spring and one 2-3 week old chick eating brine flies while resting in a small scrape near Stinking Lake. Brine flies make up a significant part of the diet of Snowy Plovers when they are at Malheur, though they eat a variety of aquatic and semi-aquatic invertebrates and crustaceans throughout their range.
While the Snowy Plovers were the focus of this survey, there were also many nesting and foraging Willet. American Avocet, Black-necked Stilts, and hundreds of Franklin’s, Ring-billed, and California Gulls were also foraging on the brine fly hatch at Stinking Lake and in the mud flats adjacent to the springs at Harney Lake.
In an effort to understand the current population trends for Snowy Plovers, Portland Audubon will work with Malheur National Wildlife Refuge staff to continue these surveys into the future. Portland Audubon will also work with Friends of Malheur NWR to recruit volunteers to assist with this important community science effort. Stay tuned for information about next year’s efforts (available in early 2023).