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Snowy Plover Monitoring Volunteer Makes a Surprise Discovery

By Wildlife Biologist Matt Lau, Point Reyes National Seashore and San Francisco Bay Area Inventory & Monitoring Network
Two newly hatched snowy plover chicks next to a still-intact egg in a shallow sandy depression lined with large pebbles. Both the chicks and the egg are a mix of light and dark, blending in with the speckled sand.
Researchers haven’t seen any snowy plovers nesting on Drakes Spit since the late 1980s. But not only did monitoring volunteer Wanda Bonneville find a snowy plover nest there this season, she found one that was in the midst of hatching!

NPS / Wanda Bonneville

July 2024 - On July 8th, National Park Service monitoring volunteer Wanda Bonneville started her first breeding western snowy plover survey on Drakes Spit. She didn't expect to find any signs of nesting, or even any adult snowy plovers, on the now-expansive spit. Neither did park snowy plover biologists. Researchers haven’t seen any nesting activity on Drakes Spit since the late 1980s. Well, not only did Bonneville find a snowy plover nest, she found one that was in the midst of hatching!

Point Reyes Bird Observatory (now called Point Blue Conservation Science) biologists monitored plovers at Drakes Spit from 1986–1989, and picked up monitoring there again in 1995. Today, they still monitor breeding plovers in Point Reyes in partnership with the National Park Service. They found as many as four adult plovers nesting on Drakes Spit in the 80s. In its 2007 western snowy plover recovery plan, the U.S. Fish and Wildlife Service designated the area as important habitat for the threatened shorebirds’ recovery. the U.S. Fish and Wildlife Service designated the area as important habitat for the threatened shorebirds’ recovery.

As Bonneville surveyed towards the end of Drakes Spit, she suddenly came upon two adult plovers acting distressed, vocalizing, and performing broken wing displays. Remembering her training, she cautiously looked around for a nest. When she found it among the vast sandy expanse, two chicks had hatched and were relatively dry. A third chick was still working its way out of the egg.

Three people with binoculars converse as one of them kneels on the ground on an expansive stretch of sand.
Snowy Plover biologists Matt Lau (center) and Aiko Goldston (left) with snowy plover monitoring volunteer Wanda Bonneville (right) examining the Drakes Spit nest site.

Carleton Eyster / Point Blue Conservation Science

Early the next morning, Bonneville accompanied snowy plover monitoring team leaders Matt Lau (that’s me), Carleton Eyster, and Aiko Goldston, out to the spit. We wanted to attempt capture of the newly hatched chicks to band them as part of the National Park Service’s plover monitoring and management program. We found all three chicks over 150 feet away from the nest site with both adults. We were able to capture all the birds, and band the chicks and the previously unbanded adult male. The adult female, bo:ry (blue and orange on the left leg, red and yellow on the right leg), turned out to be a one-year-old bird from Zmudowski State Beach in Monterey Bay.

Drakes Spit generally oscillates between small and large, as the wind and sea conspire to reshape it. It’s been on the larger side for a few years now, following a series of years when it was smaller. A lot of beach debris has accumulated, along with coarse rocks and sand that can provide good camouflage for nests. We can’t really know why plovers left, or why this pair returned, but possibly the spit’s habitat has cycled back to a more enticing state for plovers.

Biologist gently holding an adult snowy plover with two colored bands on each of her legs.
Point Blue Conservation Science biologist holding the adult female western snowy plover banded bo:ry (blue orange, red yellow) to inspect the integrity of her plastic color bands. She turned out to be a one-year-old bird from Zmudowski State Beach in Monterey Bay.

NPS / Wanda Bonneville

We continued to monitor the survival of the pioneering Drakes Spit brood at least once a week. It takes on average 28 days for the hatchlings to fledge—to grow and to become fully independent of the adult male plover and capable of flight. We're excited to report that two of the three chicks fledged as of August 5th.

Snowy plover adults tend to return to the same nesting sites where they’ve succeeded before, and juveniles have a relatively high tendency to return to the beaches where they were hatched. As a result, all of us on the snowy plover monitoring team are hopeful that this plover family may be back next year to nest. To have western snowy plovers regularly returning this bit of former habitat would be a small yet exciting step forward on their path to recovery!

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Last updated: August 7, 2024