Inference from presence-only data; the ongoing controversy


T. Hastie, Statistics Dept, Stanford Univ., CA 94305, USA. E-mail:


Presence-only data abounds in ecology, often accompanied by a background sample. Although many interesting aspects of the species’ distribution can be learned from such data, one cannot learn the overall species occurrence probability, or prevalence, without making unjustified simplifying assumptions. In this forum article we question the approach of Royle et al. (2012) that claims to be able to do this.