Using 10-years of population monitoring data to assess breeding productivity of the Oregon Spotted Frog (Rana pretiosa)

Relationships between changing environmental variables and amphibian populations have been understudied. Yet, alterations to temperature and precipitation have been suggested as contributors to the decline of some pond-breeding species, such as the Oregon Spotted Frog (Rana pretiosa). R. pretiosa has been classified as the most endangered amphibian within Canada, yet the cause for its decline is unknown. Therefore, this paper examined associations between temperature and precipitation and R. pretiosa population trends using a 10-year data set from two breeding populations in the Lower Mainland of British Columbia. Timing of oviposition was positively related to higher temperature and increased precipitation within both populations (p<0.05). No statistical relationship was determined between egg mass productivity and temperature of precipitation; however, this paper proposes that further research, consistent protocols and longer study periods, is mandated to determine environmental variables as a possible predictor of population success. This paper recommends the evaluation of breeding success through survivorship studies, as such methods provide insight into productivity as the primary determinant for population recruitment. Further, ecological restoration efforts can be implemented to help ameliorate negative consequences climate change poses on reproductive success