It’s spring in Utah! I can still see snow in the mountains but my yard is looking lush and green. I am enjoying the rain while I can; I know that once summer rolls around these steady rain storms will be few. Despite my excitement about April showers and the warm weather, a recent article in Wildlife Biology has me thinking about winter. During the winter, many wildlife species are under extreme stress compared to other times of the year. Food is scare and therefore animals are at a risk of not replenishing any extra energy expenditure that may be undertaken. As such, winter recreation – while not having a huge impact on soil and vegetation – can be a serious threat to wildlife species. Some species are known to be especially sensitive to recreation, especially off-trail use by recreationists. Wildlife can adapt to the predictive nature of on-trail recreation but the sporadic and seemingly unpredictable nature of off-trail use can lead to serious ramifications for wildlife. Wildlife species often respond to recreationists like they do predators – flushing, releasing stress hormones, and overall just using energy that could have been saved for other activities (feeding, reproducing, growing, etc.).
Coppes and Braunisch were interested in seeing if off-trail use by winter recreationists was predictable. Could they determine where human-wildlife conflicts might occur in a protected area in Germany using spatial modeling?
First, Coppes and Braunisch identified the spatial areas where they thought two species of wildlife in the Black Forest of Germany (sounds scary…) would be sensitive to recreation disturbance. The species of interest were red deer and capercaillie (I had absolutely no idea what that was and had to look it up). The area of the Black Forest where the study was conducted is densely populated with designated trails for winter recreation (including hiking, cross-country skiing and snow-shoeing). The area also contains trails which are close during winter use but are opened again during the summer for recreation.
The second part of the study was to determine where winter visitors to the Black Forest were leaving the designated winter-use trails. Luckily, winter recreation is fairly easy to track since recreationists leave very obvious evidence of where they leave the trail and how far off-trail they travel. Foot/ski searches were used to identify where recreationists had left the trail after each snowfall and field technicians would follow the visitor-created trail out 50 meters where a 100 meter buffer was set up where environmental measures were taken. The environmental variables examined included slope, canopy measures, succession stage of the forest, measures of the undergrowth of the forest, and the presences of trail signs.
A machine-learning approach was taken using the program MAXENT to determine what environmental variables were associated with visitors leaving the trail. All types of recreatonists behaved relatively the same regarding off-trail use. Not surprisingly, the presence of trail signs was the most important variable in determining where people were most likely to leave the designated trail, followed by slope, and succession stage (regeneration and old-growth). A spatial model was generated by over-laying key wildlife habitat for the red deer and the capercaillie with an off-trail use probability surface. For red deer, locations that had a high probability of people leaving the trail overlapped with important habitat in 6 locations. For capercaillie, the high probability of off-trail use areas overlapped with key habitat in 56 locations.
The results from this study show that there are locations where recreation use may be negatively impacting wildlife. Unfortunately, the researchers did not show a map of actual off-trail use overlaid with key wildlife habitat. But the study did demonstrate that human behavior can be fairly well predicted under certain scenarios. Coppes and Braunisch make some really insightful management implications at the end of their paper. Winter recreationists are expected to stay on the designated winter use trails, however signage for summer trails is the biggest predictor for off-trail use. Luckily, cheap and easy management practices such as covering the signs or adding additional signage during the winter could help contain visitors to the “correct” trails. Although managers cannot do much about the slope along trail corridors, in highly critical areas, planting of trees can be used to make the forest appear more “closed” and less appealing for off-trail travel.
Finally, as someone trained in the social science, I really appreciate (and was actually super excited to see) the authors’ recommendations for future research. Even though they demonstrated that they could predict where people may leave the trail, the study did not explore the idea of why people leave the designated trail. The authors suggest that “pattern of visitor movements might best be studied using a combined approach of visitor questionnaires and a spatial analysis of the tracks leaving the trail”.
That research approach sounds awfully familiar….
Coppes, J., & Braunisch, V. (2013). Managing visitors in nature areas: where do they leave the trails? A spatial model Wildlife Biology, 19 (1), 1-11 DOI: 10.2981/12-054