Washington State Snowy Plover Population Monitoring, Research, and Management: 2024 Nesting Season Research Progress Report

During the 2024 western snowy plover (Anarhynchus nivosus nivosus) nesting season, we counted the number of adult snowy plovers at most potential nesting sites in Washington and monitored breeding phenology, nest success, and fledging success at five sites. Work was conducted by Washington Department of Fish and Wildlife, US Fish and Wildlife Service, Shoalwater Bay Indian Tribe, and Ecostudies Institute. Management activities included restricting human access to nesting sites and restoring nesting habitat.

Thirty breeding adult surveys at ten sites were conducted between 20 May and 20 June 2024 to assess site occupancy status or to count the total number of adults detected. The mean 2024 Washington breeding adult population was 123 (range: 98-152). Breeding adults were observed at Copalis Spit, Connor Creek, Ocean Shores, Midway Beach, Empire Spit, Graveyard Spit, and Leadbetter Point (Table 3).

A total of 174 snowy plover nests were observed on Washington beaches at Copalis Spit, Connor Creek, Ocean Shores, Midway, Empire Spit, Graveyard Spit, and Leadbetter Point. Nests at Copalis Spit, Connor Creek, Midway, Empire Spit, and Graveyard Spit were monitored closely in order to calculate nest and fledging success. Forty (23%) of the 174 nests were confirmed through regular monitoring to have hatched. Corvid predation was the primary cause of nest failures, with 53 nests lost to corvids. The average number of young fledged per adult male was 1.03 (range: 0.87-1.17), representing a growing population in Washington. This represents the first year since 2018 that hatch and fledge success could be evaluated for Copalis Spit, Connor Creek, and Midway, and only the second consecutive year of fledge data for Empire Spit and Graveyard Spit since 2018.