Sea-Level Rise Could Eliminate Endangered California Sparrow Habitat
A study published in Ecology and Evolution demonstrates the likely impacts of sea-level rise on the endangered Belding’s Savannah Sparrows. The paper, co-authored by SW CASC researchers Karen Thorne and Glen MacDonald along with 10 others, was based on research partially funded by the SW CASC.
According to researchers, estuarine sparrows are at particular risk of extinction due to relatively narrow niches in which they can nest and feed. Sea-level rise is predicted to increase in the next century, reducing estuarine habitats considerably. Prior studies have hypothesized extinction of some species as early as 2035. The authors modeled habitats for the Belding’s Savannah Sparrows and ran three possible sea-level rise scenarios through 2110. Even the “low” sea-level rise scenario resulted in less habitat for the birds, while the “high” scenario predicted complete loss of habitat by 2110. Other bird species would be severely affected as well.
The authors warn that complete extirpation of the sparrows could occur even before all of their habitat is lost, as the birds require a minimum of 10 hectares to support breeding, and that “a patchy distribution of marginal breeding habitat might preclude nesting well before our model predicts full breeding habitat loss.”