A baited-camera trapping method for estimating the size and sex structure of African leopard (Panthera pardus) populations

Amongst Africa's large predators, leopards (Panthera pardus) are arguably the most elusive carnivore. Information on the species is lacking in most areas where they are found. This is because leopards are largely solitary, cryptically coloured and nocturnal making the collection of accurate population data difficult. As a result, population estimates from methods such as spoor and scat counts are less reliable. This is a concern because accurate census data are essential for informed policy and management of threatened species such as leopards. Camera trapping has emerged as a powerful tool for inventorying and monitoring carnivores in their natural habitats. Pictures from camera traps allow unambiguous individual identification making these data useful for generating accurate population estimates from capture-recapture analysis. Conventionally, camera trapping uses two cameras to record passing subjects at unbaited stations but the design usually suffers from low capture rates. Here we report on the Baited-Camera Trapping (BCT) method which uses bait and single cameras at sampling stations to survey free ranging leopards. Using bait to improve the quality of data collected in population studies is not a new strategy but arranging baits and cameras according to the BCT method is a novel approach to achieving this goal. We show that the method can significantly enhance capture rates, improve individual identification and reduce cost when sampling leopards. Furthermore, the method allows easy sex determination and collection of morphometric data from camera trap photographs. The BCT method has been tested in semi-arid savannas and we give recommendations for application in other environments and species. • The BCT method uses baits and single cameras to record leopards at sampling stations. • The provision of a leading pole enables easier individual identification and sex determination. • The method can be used to investigate multiple population monitoring questions which enhances its cost-benefit ratio.