RECOVERY OF THE THREATENED SAN CLEMENTE ISLAND BELL'S SPARROW

Susan Meiman; Institute for Wildlife Studies; bridges@iws.org; Steven Munoz, Melissa A. Booker, Andrew S. Bridges, David K. Garcelon, David K Garcelon

The San Clemente Island Bell’s sparrow (Artemisiospiza belli clementeae) was listed as a federally threatened species in 1977. The population at the time of listing was estimated at 93 individuals and the low population size was attributed to habitat degradation caused by feral goats (Capra hircus), feral pigs (Sus scrofa) and black-tailed deer (Odocoileus hemionus columbianus) and predation by feral cats (Felis catus). The US Navy, who owns the island, undertook the removal of all the large non-native mammals, initiated propagation and planting of native vegetation, and instituted an aggressive fire management program. In 1999 the Institute for Wildlife Studies started annual population monitoring. Initial survey focused on historic nesting habitat and population estimates ranged from 452-1,546 adult sparrows. When sparrows were observed using other nesting substrates and habitats, monitoring was expanded to island-wide surveys. The 2013-2021 breeding season estimates ranged from 4,198-6,364 adults and in 2021 the estimate was 6,307 adults. Based on the expanded spatial use of the island, the large and stable population size, and reduced threats, in 2021 the USFWS proposed delisting the species.

Bird Ecology and Conservation  InPerson Presentation