A global review of the conservation threats and status of mustelids

The family Mustelidae is the largest among the order Carnivora. While we know a great deal about certain species, there is still a lack of information about many mustelids. We first investigated the International Union for Conservation of Nature (IUCN) Red List species-level assessments for each mustelid species. Then, we undertook a systematic review of the scientific literature with the aim of identifying the primary threats and subthreats reported, and which species are most studied. Threats are defined by the IUCN as "the proximate human activities or processes that have impacted, are impacting, or may impact the status of the taxon". We analysed 1003 published articles. For each article, we collected year of publication, geographical zone of each study, species studied, and the threats and subthreats identified. The majority of species (62%) were classified as Least Concern on the IUCN Red List, but 31 out of 63 species were found to be declining globally and only two species were increasing. The species studied and location of studies were biased, with 72% of studies undertaken in North America or Europe and focussing on very few species. A high proportion of species distributed predominantly in the tropics were categorised as declining, and threats linked with hunting, fishing, and logging were identified as the most common for mustelids by the IUCN Red List and in the scientific literature. Differences in the proportion of threats affecting each subfamily were also reported. The nature of threats varies in different parts of the world and between species. It is essential to undertake more research with a strong focus towards species in highly biodiverse regions. A greater understanding of threats such as wildlife pet trade, emerging diseases, and climate change must also be central to prevent declines.