Frog population viability under present and future climate conditions: a Bayesian state-space approach.

Area of Science:

• Ecology
• Climate Change Biology
• Conservation Biology

Background:

• Amphibian populations face global extinction risks, with climate change as a significant driver.
• Changes in climate mean and variability can unpredictably affect amphibian populations.
• Montane amphibians in western North America may be impacted by reduced snowpack and increased precipitation variability.

Purpose of the Study:

• To estimate survival and transition probabilities of Columbia spotted frogs (Rana luteiventris) over 10 years.
• To assess the relationship between these rates and interannual snowpack variation.
• To forecast population growth and viability under various climate change scenarios.

Main Methods:

• Utilized Bayesian capture-recapture methods for population analysis.
• Collected 10 years of data on a high-elevation Columbia spotted frog population.
• Developed population models incorporating changes in snowpack mean and variance.

Main Results:

• Changes in mean snowpack had a greater impact on population viability than changes in snowpack variance.
• Future scenarios largely predicted an increase in population viability.
• Population models based on historical snowpack predicted a declining population.

Conclusions:

• While mean snowpack is crucial, increased climate variability can shift populations from increasing to decreasing.
• The Bayesian modeling framework effectively characterizes uncertainty in ecological forecasts.
• Species longevity and habitat heterogeneity may confer resilience to climate variation.