The Extent To Which Wildlife Avoid Human Activity
In many ways, the effects of human activity on wildlife are well-documented, such as the displacement of wild animals due to deforestation and urbanization. However, less is known about more subtle phenomena, like nature-based tourism in national and provincial parks. While recreational activities like hiking can promote the conservation of such parks, they may inadvertently disrupt ecosystems. Assessing the consequences of human recreational activities on wildlife is difficult because, just like the phenomena themselves, their effects will be more subtle than land-use change due to human infrastructure. There are other problems as well: not all species react similarly to anthropogenic events, and gauging visitor numbers can be difficult, making the cause of changes hard to pin down. One solution is to use motion-triggered cameras to non-invasively track both human and wildlife activity. Indeed, researchers used this technique to assess the effects of recreational usage on wildlife assemblage within a provincial park in British Columbia, Canada.
This park spans 568km2 of forested mountains and is home to a variety of predator (e.g., grizzly bear and wolverine) and prey mammals (e.g., moose and mule deer). Additionally, the park is exploited for a mixture of industries including ranching, mining, and home developments, with logging and recreation being the key causes of anthropogenic changes. However, little is known about how current land-use is affecting wildlife in this park. For this study, 61 cameras were deployed on trees next to trails or roads across 550km2 of the park using a hexagonal grid. Cameras were active from May to September in 2018 and captured photos of amphibians, birds, and mammals, in addition to human activities that were categorized as hiking, horseback riding, mountain biking, and motorized vehicles.
At least 13 different species had sufficient data for analyses, including grizzly bears, moose, cougars, and red squirrels. Each species was noted as being detected (yes/no) for each week sampled. The probability of a wildlife detection by each of the four recreational activities were modelled, along with the impact of environmental variables (e.g., road length, percentage of land used for logging, and percentage of land that isn’t forested). Furthermore, a second analysis calculated the ratio between the time a human was detected at each site and when the previous and subsequent wildlife was detected. Values less than one indicate ‘attraction’ while values greater than one indicate ‘avoidance’.
Results revealed that human activities were more frequently captured than wildlife. For example, mountain biking was the most detected event, with twice as many captures as mule deer, which was the most detected species. Likewise, all recreational activities had higher numbers of detection than almost all species sampled. Interestingly, human recreation did not show consistent effects among animals’ usage of trails. Specifically, while the number of mountain bikers increased, the probability that a grizzly bear or moose would be detected decreased. In contrast, the number of hikers was positively associated with the likelihood of a grizzly bear using the trail. Likewise, the number of motorized vehicles also increased the chance of detecting a Canadian lynx and a spruce grouse. Despite this, the second analysis demonstrated that all 13 species avoided trails recently used by humans, with mountain biking and motorized vehicles showing the strongest avoidance, followed by horseback riding and hiking.
While this is a novel study that used cameras to examine human and animal landscape use, one limitation was that cameras were only situated by trails and roads. Consequently, the authors were unable to conclude whether wildlife generally avoided these areas, or if animals only avoided them during human activity. Nonetheless, if visiting a national park, it is crucial to acknowledge that you are entering into the homes of countless wild animals. As an advocate, one can avoid mountain biking and off-road driving in such parks to potentially minimize any disturbance and displacement to wildlife.