SCIENCE SNIPPETS: WHY DID THE WILD DOG CROSS THE FENCE?
ERIN ADAMS AND LIZANNE ROXBURGH, THE EWT’S CONSERVATION PLANNING AND SCIENCE UNIT
Within South Africa, fences are used to contain wildlife in reserves to protect them, particularly in human-dominated landscapes where they could easily come into conflict with people if they leave the reserve. This is especially true for medium to large-sized carnivores. However, they do cross these fences, and once outside, they are exposed to risks such as snaring, persecution, and collisions with vehicles, and any livestock they kill can incur high costs in the form of retaliatory killings by farmers. However, the reasons why they cross fences are not well understood.
African Wild Dog conservation, especially in southern Africa, often includes the translocation of wild dogs from one or more reserves and the formation of a new pack in a different reserve to ensure that genetic diversity is maintained and that population sizes are appropriate. In a recent publication co-authored by EWT scientists*, the reason behind why African Wild Dog packs cross reserve fences was investigated. Using a long-term dataset, they studied 32 Wild Dog packs across five reserves in the KwaZulu-Natal province in South Africa over 14 years. During this time, they recorded 154 events when Wild Dogs crossed fences. They looked at several factors that could be linked to fence crossings, including prey densities, rainfall, wild dog pack size, and the number of lions in the reserve.
The scientists found that the age of the pack (i.e., whether it was newly formed or well-established) and the fence integrity affected whether or not Wild Dog packs crossed the reserve fence. When fence integrity was poor, the probability of packs crossing the fence was higher, especially with newly established packs. This happens in their exploratory phase when they look for territories to occupy in the new reserve. When fence integrity was average, more established wild dog packs were more likely to escape to increase the size of their territories. When fence integrity was good, the probability of packs crossing fences was very low. Reserve management should ensure that the fence’s integrity is good to prevent these crossings. It is also important to carefully manage packs that reach about 3.5 years old, as this is when they would be more likely to expand their territories and attempt to cross the fence.
*Stone, D. W., Kelly, C., Marneweck, D. G., Druce, D. J., Hopcraft, J. G. C., & Marneweck, C. J. (2022). Fence management and time since pack formation influence African Wild Dog escapes from protected areas in South Africa. Journal for Nature Conservation, 70, 126291.