Frequent flight responses, but low escape distance of wild boar to nonlethal human disturbance

Abstract

Human activities can affect the behaviour and fitness of wildlife. However, the response of animals to nonlethal human activities has not been well-studied in wild boar, Sus scrofa, even though it is a widespread species in Europe and has become of increasing concern because of crop damages and its vector capacity for diseases. We study the behavioural responses of GPS-collared wild boar to nonlethal experimental human approaches in the Bohemian Forest Ecosystem along the border between Germany and the Czech Republic. We describe and quantify the flight responses of the animals and assess whether they vary with the distance to recreational paths and the occurrence of hunting in the area. We show that wild boar were disturbed and displaced by human approaches on foot in 69% of the trials, but the average flight initiation and escape distances were relatively small (93 and 256 m, respectively). The probability of a flight response decreased with distance from the paths and increased with the ruggedness of the terrain. In the non-hunting zone, the flight initiation distances and flight durations were shorter than in the hunting zone. Our results suggest a weak effect of nonlethal human disturbances on the movement of wild boar, although the animals were sensitive to the perceived risk in relation to recreation infrastructure and hunting. For the management of diseases such as African swine fever, it can be concluded that nonlethal disturbances are unlikely to accelerate the spread of the disease due to far-distance movements. Guidelines for restrictions in case of an outbreak might be adjusted accordingly.