There were many studies on the relationship between free-ranging dogs and deers; however, the impact differs from place to place. The present study was conducted from January 2002 to June 2003 as an effort to understand the significance of the free-ranging dogs on the sika deer population in She-ding area, Kenting National Park. The incidences of the dog-related death of the sika deer were recorded during the study period, and auto-camera and transect line survey were used to record the activity of the dog. Finally, VORTEX simulation was conducted to evaluate the possible impact of dogs’ predation on the sika deer population.
A total of 37 hours was completed for survey on the 11 transect lines and only 7 dogs were recorded. For the auto-trigger cameras, 62745.1 hours were completed by the 31 cameras and 32 pictures of dogs were recorded. At the same time, a total of 39 dog-related deer deaths was recorded during the study period. Results showed that free-ranging dogs occurred in the She-ding area were mostly house dogs. They occurred in the field at the same time and area as local residents did. No feral dog was appearing in She-ding area. Moreover, based on the VORTEX simulation, the present predation level of sika deer by free-ranging house dogs will slow the population growth of the sika deer, which can be serious for a re-established small population. Therefore, a better management of the local house dog will largely eliminate their threat to the sika deer population. It was also found that the fence of protective area for the sika deer not only can not prevent the invasion by the dogs, but will also block the way of the deer when they were trying to escape from the chasing dogs. An improvement of the fence is necessary.