The Pacific Coast population of the Western Snowy Plover (Anarhynchus nivosus nivosus) is a federally Threatened species and is a California Species of Special Concern. Knowledge about their nest site selection requirements is important to this species’ management in the San Francisco Bay area. We measured the percentage of sand, percentage of crushed oyster shells, number of shells, and total shell surface area for 56 nests of Western Snowy Plover at the California Least Tern colony at Hayward, California, over a 14-year period (2008-2021). Using pairwise t-tests, we compared these measurements to those obtained from 56 randomly chosen non-nest sites. Results indicate that plovers select nest sites with greater oyster shell metrics than paired random sites. The contrast in the shell-related nest metrics (i.e., the difference between the nest site and the paired site) showed significant, positive relationships with both hatching success and number of fledglings using linear regression analysis. These results, supporting federal species recovery, suggest that the Western Snowy Plover may improve their nesting success through oyster shell enhancement, which may provide more camouflage for the eggs and chicks than locations with fewer shells.

David (AKA “DOC QUACK”) Riensche, a Certified Wildlife Biologist, is a Wildlife Biologist II for the East Bay Regional Park District where he has worked for over 36 years. For 28 years he has been a member of the Biology Department faculty at Las Positas College, where he teaches courses in biology, ecology, and vertebrate natural history. He is a recipient of The National Association for Interpretation (Region 9) – Outstanding Field Naturalist Award. David holds advanced degrees in both Natural Resource Management and Environmental Education, and an undergraduate degree in Biology (Wildlife). His current wildlife research and habitat restoration efforts are diverse, focusing on the following species and groups: California Least Tern, Western Snowy Plover, Black Skimmer, Forster’s Tern, Western and Clark’s Grebes, Bald Eagle, Ridgway’s Rail, California Black Rail, Burrowing Owl, California Red-legged Frog, California Tiger Salamander, Western Pond Turtle, Salt Marsh Harvest Mouse, San Francisco Dusky-footed Woodrat, Bats, Fairly Shrimp, Central California grassland lizards and small mammals, riparian and oak woodland breeding bird community structure, shorebird nesting population studies, upland gamebirds and waterfowl management