The beetle fauna of the island of Koltur and a new record for the Faroe Islands

Koltur is a small (2.5 km2) island located in the central part of the archipelago of the Faroe Islands. Apart from its two permanent inhabitants and the currently 160 sheep grazing on the island, there is relatively little human influence. Despite its small size, a variety of habitats occur on Koltur, such as steep mountain slopes, wetlands, grasslands, sea bird colonies, rocky shores, and a unique beach with a high proportion of shell sand.
Extensive pitfall trap sampling on Koltur conducted in June/July 2019 and 2020 revealed at least 42 species of Coleoptera, which represents around 23% of the known beetle fauna of the whole country. The majority of them belong to the beetle families Carabidae and Staphylinidae. The most abundant species were Loricera pilicornis, Patrobus septentrionis (both Carabidae), Tachinus rufipes, and Quedius nitipennis (both Staphylinidae). Also widespread but less numerous were Nebria salina, Notiophilus biguttatus, Trechus obtusus (all Carabidae), Stenus brunnipes, Othius angustus, and Cypha laeviuscula (all Staphylinidae). Species were not evenly distributed over the island, but their distributions reflected different habitat types and altitudes in line with their reported ecology.
Among the beetles collected in Koltur was a new record for the Faroe Islands, the dung beetle Aphodius borealis (Scarabaeidae, Aphodiinae). Fifteen individuals of A. borealis were collected from sheep dung in 2019 and the species was given the Faroese name Norðurtøðklukka.