Small mustelids in peril: Investigating detection, abundance and ecology in the Netherlands

Small mustelids of the Mustela genus within the Mustelidae family are widespread across the northern hemisphere and parts of the southern hemisphere. In recent years, they have become an increasing conservation concern due to suggested declining populations. The three small mustelid species that occur in the Netherlands — the European polecat Mustela putorius, stoat Mustela erminea, and common weasel Mustela nivalis — have been suggested to be declining in either range or population numbers across their European range. In the Netherlands, the conservation status of the European polecat and stoat has been listed as ‘vulnerable’ and the common weasel as ‘near threatened’ on the national red list, following IUCN standards. With rising conservation concerns, there is need for more research on small mustelids occurring in the Netherlands to estimate population distribution and size, and to effectively apply conservation methods. Hence, our project focuses on four different topics which will hopefully prove useful in the protection of these three illusive species. Our study takes place in areas in the north of the Netherlands, consisting of Natura2000 nature reserves and meadow-bird conservation habitat. First, we tested three different camera-trapping methods to examine which method most efficiently detected the different species. The results
of this study will be applied in camera grids in three consecutive years to estimate abundance of the different species. Concurrently, we aim to track stoats with GPS-collars during the camera grid study period to study habitat use and link this to prey and predator abundance and landscape characteristics. Finally, we plan to combine all data to create species distribution models for all three species for the whole of the Netherlands to mark so called ‘small mustelid hotspots’. These models will be compared with national observation models and supplemented with abundance estimates to estimate current number of small mustelids in the Netherlands.