Showing papers by "R. J. van Aarde published in 2007"
TL;DR: In this article, the authors investigated the effect of ambient temperature on landscape use in free-ranging elephants using GPS collars and found that elephants may select landscapes based on the rate at which temperatures changed and also for shading.
82 citations
TL;DR: Standard mark–recapture field methods are used to obtain estimates of population size with associated confidence limits for a closed elephant population in the Tembe Elephant Park, South Africa, and Bowden's gives an estimate closest to the registration count.
Abstract: Elephants living in dense woodlands are difficult to count. Many elephant populations in Africa occur in such conditions. Estimates of these populations based on total counts, aerial counts and dung counts often lack information on precision and accuracy. We use standard mark–recapture field methods to obtain estimates of population size with associated confidence limits. We apply this approach to a closed elephant population in the Tembe Elephant Park (300 km 2 ), South Africa. A registration count completed in 4 months gives a known population size. We evaluate mark–recapture models against the known population size. Individual identification profiles obtained for elephants during the registration count and mark–recapture events indicate that at least 167 elephants live in the park. We consider this value as an estimate of the minimum number alive. We include 189 sightings of bulls and 37 sightings of breeding herds in the mark–recapture modelling. Of the models we test (Petersen, Schnabel, Schumacher, Jolly–Seber, Bowden's, Poisson and negative binomial), Bowden's gives an estimate closest to the registration count. Assumptions of the model are not violated. For all models except one
32 citations