For species with boom-and-bust life cycles, such as amphibians, perspective across time contributes to our understanding of long-term trends in occupancy on the landscape, and mechanisms affecting those trends. This is particularly pertinent to protected areas, where changes may occur more slowly than in more highly impacted landscapes. 

Researchers used over 30 years of amphibian survey data from Rocky Mountain National Park to estimate changes in occupancy, colonization, and persistence probabilities of three amphibians: boreal chorus frogs, wood frogs, and tiger salamanders. They also explored the potential for landscape change and visitor use to act as drivers behind observed changes.  

Results indicate that colonization and persistence are low and/or declining for the three studied species. They also found that occupied catchments are increasingly isolated, and that visitor use had a consistently negative effect on occupancy and persistence of amphibians in the park. Additionally, habitats that have become less complex (that is, grassier habitats instead of more complex willow-dominated habitats) are less likely to support persistence or colonization. While these results are sobering, they also provide a way forward where mitigation efforts can target identified drivers of change. For example, by identifying potential drivers, the study provides managers with an opportunity to develop proactive strategies that halt or reverse some of these observations.