A Localized Decline in the Western Chorus Frog, <em>Pseudacris triseriata</em>, in Eastern Ontario

To assess whether Western Chorus Frogs have declined in eastern Ontario, we conducted amphibian call surveys at 18 sites in the Cornwall area, where they were heard calling in 1990, as well as selected wetlands in the same area. Chorus frogs were detected at only 1 of the 18 original locations during surveys in 2001 and 2007. When survey locations with and without Chorus Frogs were considered, the site occupancy rate declined from 58% in 1990, to only 12% in 2007. Chorus Frogs appear to have declined in this area of eastern Ontario which is adjacent to documented declines in western Quebec and northern New York.