Sir, Leg-hold traps are the devices most commonly used by researchers to capture wolves. These traps can cause injury, as they cannot usually be monitored closely enough to prevent captured animals from struggling in them. In areas where guard dogs are not used, typical methods for controlling wolf predation on livestock are culling and building substantial or electric fences to exclude wolves. These methods have two major drawbacks - culling can threaten the population, and conventional fences are expensive and difficult to maintain.