Humboldt State plover research a multi-prolonged effort

Paul Mann
Mad River Union

ARCATA — Veteran Humboldt State University Wildlife Professor Mark Colwell and his graduate students partner with multiple agencies in monitoring nesting snowy plovers along the Northern California Coastline.

Anchored by the U.S. Fish and Wildlife Service (USFWS) in concert with the Ecological Services Program of the Arcata Fish and Wildlife Office, researchers recorded the first plover nests at Freshwater Beach last April. One succumbed to predation but the other nest fledged three chicks successfully this past summer.

A year ago this month, population growth was up in the northern California region for the seventh consecutive year. Nests were found for the first time at Tolowa Dunes State Park. A recovery benchmark of one fledgling per male per year was exceeded for the first time since monitoring was initiated.

Since 2000, Humboldt State’s Shorebird Ecology Laboratory has been supported in the annual monitoring program by staff or volunteers from California State Parks, the Bureau of Land Management, the National Park Service, Friends of the Dunes and the Audubon Society, as well as from the USFWS.

COMEBACK KID The Western Snowy Plover is doing better, but has a long way to go. Photo by Luke Eberhart-Phillips

Nesting snowy plovers are tracked from the California-Oregon border to southern Mendocino County. The Ecological Services Program of the Arcata Fish and Wildlife Office helps fund the initiative at 28 sites within coastal northern California.

Monitors record the numbers of breeding plovers, the nests initiated, eggs hatched and the chicks fledged. Evident causes of egg and chick loss are monitored during the March-September breeding season.

As documented by Colwell and his students’ research, plovers are vulnerable to multiple threats locally – not only high rates of predation but also habitat loss and human impacts.

In a synopsis prepared exclusively for the Union, the USFWS states,

“In an attempt to remedy habitat loss, removal of exotic beachgrass in Humboldt County has been successful at improving plover habitat and reproductive success as well as restoring native plant and animal communities. In our area, snowy plovers experience high rates of nest failure due to predation, typically caused by ravens but also by other bird species (crows, raptors, and owls) as well as mammalian predators including raccoons and skunks.”

Researchers have documented the destructive impacts of human activities, Clam Beach being a prime example.

In the federal agency’s words, unintentional human encouragement of larger predator populations – canines – makes matters worse.   

“Biologists have documented footprints of humans and dogs coming within inches of the well-camouflaged nests. Repeated disturbances by dogs and humans can interrupt brooding, incubating and foraging of adults and lower reproductive success. Frequent movements by plovers around these nests also cue predators to the location of nests, indirectly increasing predation risk.”

Beach litter, kites, fires and camping sites pose threats as well. Detailed information is posted on the Arcata Fish and Wildlife species page at

A video, “The Snowy Plover and You (Charadrius nivosus nivosus),”is posted at


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