Population dynamics and methodological assessments from a 15-year period of Amphibian monitoring in British Columbia's Southern Gulf Islands.

With amphibian populations facing a multitude of threats, including habitat loss, climate change, invasive species and infectious diseases, it is important to identify valuable amphibian habitat and the imminent pressures these environments face. Between 2004 and 2019, 6 years of amphibian surveys were conducted at Greenburn, Roe and McLean lakes in the Southern Gulf Islands of British Columbia, Canada. We assessed (1) species composition and trends of native amphibians, including at-risk northern red-legged frog (Rana aurora); (2) observations of invasive American bullfrog (Lithobates catesbeianus); and (3) the efficacy of visual encounter and trapping survey methods in determining multi-species amphibian occupancy.