Washington State Snowy Plover Population Monitoring, Research, and Management: 2012 Nesting Season Research Progress Report

During the 2012 Western Snowy Plover (Charadrius nivosus nivosus) nesting season, we monitored breeding phenology, nest success, fledging success and number of nesting adult plovers in Washington. Field monitoring and research was conducted by Sara Peterson, Cyndie Sundstrom, William Ritchie, and Sue Thomas with assistance from Brock Hoenes, Warren Michaelis, Steve Spencer, Lorenz Sollmann, and Sue Mayo. Management activities included restricting human access to nesting sites, exclosing nests to prevent predation, and nesting habitat restoration. A summary of some of our 2012 activities and results:

Breeding Phenology

• Clutches were initiated between 21 April and 13 July (Figure 3). However, very early nests could have gone undetected because intensive surveys did not start until late March on Midway Beach and early April at Leadbetter Point.
• The first chick known to have fledged, fledged around 20 June and the last chick known to fledge, fledged around 7 September.

Breeding Range

• We conducted 31 surveys at 8 sites between 29 April and 15 August 2012 to either assess occupancy or to count the number of nesting adults.
• Snowy Plovers were only found nesting on Leadbetter Point, Midway Beach, and Graveyard Spit. A single male was observed by Refuge Biologist Sue Thomas on 30 April on Dungeness Spit, but was not observed in three subsequent surveys, indicating that there was no local nesting in 2012.

Number of Breeding Adults

• The mean 2012 Washington breeding adult population was 33 (95% Confidence interval: 15-52). All of the breeding adults observed were found on Leadbetter Point, Midway Beach, and Graveyard Spit. Staff and volunteer surveyors conducted surveys.
• The Washington population has declined by approximately 4 birds per year over the past seven years (p = 0.015), and has declined from four nesting sites to three over the past seven years.

Nest success

• Forty-seven nests were discovered and monitored.
• The percent of nests that survived from egg laying through hatching during the 2012 nesting season was 21% (includes exclosed and non-exclosed nests).
• As in past years, the primary source of nest failure was predation. Common ravens were the only identified nest predator. However, in many cases we could not identify the nest predator.

Fledging Success

• The average number of young fledged per adult male on the three nesting sites in Washington was 0.68 (range = 0.46-0.94). Population viability analyses indicate that, on average, at least one young must fledge per adult male to have a stable population.

Management Actions

• Restrictions: Fireworks were prohibited on beaches where State Parks and U.S. Fish and Wildlife Service (USFWS) are the upland land owners.
• Nest exclosures: Three nests were exclosed on State Park land at Midway Beach and ten nests were exclosed at Leadbetter Point (7 on Refuge lands and 3 on State Park lands).
• Signing: In an effort to protect nests, approximately 7.5 miles of beach at Leadbetter Point and approximately 1 mile of beach at Midway was signed to restrict human access on the dry portions of the beach to. Access restrictions did not occur on private land.
• Nest Predation: Willapa National Wildlife Refuge continued to collect data on nest predators that occurred in and adjacent to the plover and lark nesting areas at Leadbetter Point. Logistics of implementing a proposed predator management strategy were investigated.
• Restoration: The U.S. Fish and Wildlife Service habitat restoration area (HRA) at Leadbetter Point now totals over 250 acres with 15 new acres added in 2012. Oyster shell was added to approximately 62 acres. Non-native beachgrass control includes aerial and hand spraying approximately 110 acres in the south central portion of the HRA. The north end of the shelled area in the HRA was harrowed to redistribute shells and bulldozed to remove beachgrass. In addition, the dune cuts in the swale adjacent to the west edge of the south HRA were removed in February 2013 by cutting down the adjacent dune with a bulldozer.
• No habitat restoration work was conducted on State Parks lands at Leadbetter Point or Midway Beach in 2012.

Recommendations

• Summarize, write-up and publish population monitoring results from Oregon, Washington, and northern California.
• Continue to examine the effectiveness of habitat restoration areas.
• Identify the conditions where plover populations are more likely to be self-sustaining.
• Conduct research to identify habitat features important to successful plover nesting.
• Begin implementation of a predator control plan for active snowy plover nesting locations.
• Continue to engage volunteers in monitoring.
• Continue to link management activities with research and monitoring.
• Continue to evaluate the effectiveness and continued use of nest exclosures on an annual basis.
• Evaluate impact and timing of clam digging on plover nesting, foraging and fledging.
• Initiate education and outreach activities.