Recreation ecologists are often concerned about how different recreational activities impact wildlife species. However, little research has been conducted around this topic. In 2001, Miller et al. examined how the presence of dogs (and hikers, since dogs are rarely on trails alone) influence wildlife in Boulder, Colorado. Various characteristics of a recreational activity can influence the level of impact to wildlife; these include intensity, frequency, and locations of the recreational activity. Recreation ecologists also refer to a concept called the “area of influence”. The area of influence is defined by the probability that an animal will respond at a given perpendicular distance from the recreationist. The greater the area of influence (or the greater the probability of response) the greater the impact is to the particular wildlife species in question.
Miller et al. used the concept of the area of influence to formulate the question of their study. The researchers wanted to know if area of influence differed between a pedestrian, a pedestrian with a dog (on a leash), and a dog alone. The researchers also examined if the area of influence differed based on whether the recreational activity was occurring on trail or off trail. The study was conducted on the City of Boulder Open Space land in a popular area of hiking where on trail hiking was common but off trail use was sporadic. A grassland habitat was chosen to examine responses of vesper sparrows and western meadowlarks. In the forest habitat, the researchers examined the response of robins and mule deer. The researchers examined the response (probability of flushing and the distance flushed) of each species to their six treatments (see figure below for an example of their results).
For both the vesper sparrow and the western meadowlark, the area of influence was smallest when the dog was alone. Vesper sparrows and western meadowlarks responded the most to a pedestrian while alone (meaning without a dog present). The researchers hypothesized that because dogs resemble coyotes and/or foxes – which are common in the area and not predators of songbirds – the birds are not cueing on the dogs as a threat.
Additionally, for all of the songbirds (robins included), the most response occured when the recreational activity was occurring off trail. Recreational use on trail is very common in the area but off trail use is sporadic and hence less predictable. The birds were therefore most likely not accustomed to experiencing recreational activities in off trail areas and hence the greater response.
The mule deer has a different response than the birds in the study. Dogs had the greatest influence on mule deer response. Deer can be killed by dogs (and have been attacked or killed in the Boulder area) and have been predated on by canids for their entire evolutionary history. Therefore the deer, unlike the birds, were possibly cueing onto the dogs as a potential predator. Like the birds however, deer showed a greater response to off trail recreation.
Overall the study concluded that recreational activities, especially those that occur off trail, have the potential to disturb wildlife and lead to possible wildlife displacement. Management recommendations included restricting recreational use to on trail activities (which is often an overall management goal anyways), require dogs to be leashed, and potentially zoning recreational activities. The authors also pointed out that recreationists may not be aware that their actions are influencing wildlife and therefore there is an opportunity for education. Educating visitors can encourage a conservation land ethic and therefore visitors may be less likely to engage in activities that they know can lead to environmental harm.
Miller, S.G., Knight, R.L., & Miller, C.K. (2001) Wildlife responses to pedestrians and dogs. Wildlife Society Bulletin, 29(1), 124 – 132