Estimating Alpine ibex Capra ibex abundance from photographic sampling

Monitoring procedures for Alpine ibex Capra ibex are limited in habitats with reduced visibility and when physical capture and marking of the animals is not intended. Photographic sampling, involving using camera-trap data and identifying ibex from natural markings, was adopted with capture-recapture models to estimate the abundance of ibex in Austria. The software CAPTURE's model produced an average capture probability of 0.44 with an estimate of 34-51 ibex and a mean population size of 38 ibex. This first study showed the applicability of photographic capture-recapture techniques to estimate the abundance of ibex based on their natural markings.