SEEC Stats Toolbox - Dynamic Occupancy Models

Occupancy is the state variable describing where a species occurs and is a key quantity in ecology and conservation. The problem with occupancy is that it is usually not directly observable because non-detection of a species at a site does not establish absence of that species at this site. Two earlier SEEC Toolbox seminars showed how occupancy models can be used to deal with this problem by explicitly accounting for the detection probability. Occupancy models assume closure, i.e. that a site is either occupied or not for the entire duration of the study. However, unoccupied sites do get colonised and species can go extinct from formerly occupied sites. Such changes in occupancy are often the main study focus, i.e. interest is in the dynamics rather than just static patterns. In this Toolbox Seminar, we show how dynamic occupancy models can be used to examine changes in occupancy, by estimating colonisation and local extinction.