Using geographic profiling to compare the value of sightings vs trap data in a biological invasion

Aim: The development of conservation plans, including those dealing with invasive species, is underpinned by the need to obtain reliable and accurate data. However, in many cases responding rapidly is equally critical.

Location: The data were obtained from the Hebridean Mink Project, which was set up with the objective of removing mink from North Uist, Benbecula and South Uist.

Methods: Here, we introduce an extension of the Dirichlet process mixture (DPM) model of geographic profiling that can be used to estimate source locations of invasions directly from spatial point pattern data without the need to specify dispersal parameters. We use this model to analyse a biological invasion of American mink (Neovison vison) in the Hebrides.

Results: Our results suggest that sightings data – which are relatively easy and quick to acquire – can be used to capture much of the information about sources of invasive species that is obtained from the harder to acquire and more intensive trap data.

Main conclusion: These results have important implications for the development of conservation plans and, in this case, in the early stages of biological invasions, when interventions are most likely to be successful.