Evaluating the use of citizen science data for detecting trends in climate-sensitive wildlife

Wildlife in alpine and subalpine landscapes are expected to feel the pressure of climate change sooner than their low elevation counterparts. Each year since 2008, citizen scientists have hiked hundreds of miles into Glacier... [ view full abstract ]

Wildlife in alpine and subalpine landscapes are expected to feel the pressure of climate change sooner than their low elevation counterparts. Each year since 2008, citizen scientists have hiked hundreds of miles into Glacier National Park's high country to look for mountain goats (Oreamnos americanus) and American pikas (Ochotona princeps), two species that may serve as sentinels for changes in these mountain climes. American pikas are sensitive to temperature increases and may be pushed out of their historic range. Counts of mountain goats, a notoriously difficult to study species due to the rugged terrain they inhabit, are declining throughout their range, but little is known about how resilient the species may be to climate change. Our small army of over 150 volunteers each year has provided a large amount of baseline information about mountain goats and pikas, a much-needed starting point for tracking future changes. To understand how well these population and distribution estimates can serve as an early warning signal, we needed to compare them citizen science estimates to data gathered by more traditional methods (surveys by biologist and aerial surveys). In mountain goats, although detection by biologists was significantly higher and less variable than that of volunteers, the two population density estimates overlapped and population estimates by volunteers were more similar to those from aerial surveys. For pikas, biologists were more consistent at identifying and finding pika signs than volunteers, but volunteers could reliably detect pika site occupancy. Our findings have informed changes to our mountain goat trend monitoring in Glacier and changes to pika monitoring protocols across a network of western national parks. These evaluations underscore the value of testing data quality and adapting protocols before embarking on a decade or more of monitoring to detect population level changes in wildlife.