Road use by African wild dogs: impacts of tourism infrastructure on large carnivores in Botswana

Background/Question/Methods

Advances in movement ecology allow new insights into the impact of human development on wildlife populations. In Botswana’s Okavango Delta, the ecotourism industry creates broad habitat changes through road and settlement construction; in 2012-2013 alone, over 100 kilometers of roads were built in Moremi Game Reserve to allow for greater tourist access in the park. Many studies have documented negative impacts of roads on birds and small-to-medium-sized mammals, but impacts on more vagile species such as large carnivores remain poorly understood. However, emerging research indicates that large carnivores may tolerate and even exploit roads at low human densities. To test the hypothesis that roads create efficient movement conduits for large carnivores, thus increasing speed and/or total daily distance traveled, we quantified road effects on African wild dog (Lycaon pictus) ranging behavior.

We fitted sixteen dogs in six packs with GPS collars containing accelerometers and magnetometers to record continuous movement and activity data. We classified the data points into discrete behavior categories (moving, resting, and chasing) based on movement speed and acceleration. We used conditional logistic regression in a step selection framework to evaluate the influences of landscape features, including roads, on movement choices for each of the three behaviors. 

Results/Conclusions

African wild dogs show strong road selection when moving (p << 0.001), road avoidance when resting (p = 0.03), and no road effect when chasing. Roads did not affect average travel speed nor total distance traveled on a daily scale, suggesting that processes other than movement efficiency likely drive road selection. Isolating GPS points when the collars switch into chase mode revealed that African wild dogs select for roads when initiating hunts (p << 0.01). Hunting behavior may therefore be an important driver of road selection as roads may increase visibility and/or prey encounter rates. These results indicate that roads have diverse behavioral and ecological effects on wildlife species, including impacting predator-prey interactions, which should be considered in future development planning.