The Black Skimmer (Rynchops niger), one of our most distinctive colonial waterbirds, is listed as a California Species of Special Concern. Factors affecting their breeding population include limited suitable open nesting habitat, human disturbance, varied food availability, predation (feral animals and gulls), extreme weather, and environment pollutants. It is projected that by the year 2050, due to climate change, this coastal bird will have its habitat reduced by 50%. Typically, islet-breeding skimmers are in close proximately to nesting tern species which provide early warning and defensive behaviors against intruders. Since 2001, the East Bay Regional Park District has been working to establish and enhance a California Least Tern (Sterna antillarum browni) colony at Hayward Regional Shoreline located along the eastern shore of the San Francisco Bay. These efforts are to assist in the recovery of this State and Federally listed endangered species and resulted in the attraction of breeding Black Skimmers to the site in 2015. For a total of eight breeding seasons (2015 to 2024), the Black Skimmer, California Least Tern, the threatened Western Snowy Plover (Anarhynchus nivosus nivosus) have nested successfully, in association with American Avocet (Recurvirostra americana) and Black-necked Stilt (Himantopus mexicanus). The results presented on Black Skimmer breeding chronology, hatching and fledging success, and diet in the northern portion of the species range answers data gaps that may help inform future research, protection, and management measures for this special status bird species.

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.