Using subnivean camera traps to study arctic small mammal community dynamics during winter

• Published in: Arctic Science
• Main Authors: Mölle, Jonas, Kleiven, Eivind Flittie, Ims, Rolf Anker, Soininen, Eeva M
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2021
• Subjects: VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497; VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497; Arctic; Norway; Arctique*; Lemmus lemmus; Nord de la Norvège; Northern Norway; toundra; Tundra
• Online Access: https://hdl.handle.net/10037/23459; https://doi.org/10.1139/AS-2021-0006

Small rodents are a key indicator to understand the effect of rapidly changing winter climate on Arctic tundra ecosystems. However, monitoring rodent populations through the long Arctic winter by means of conventional traps has, until now, been hampered by snow cover and harsh ambient conditions. Here, we conduct the first extensive assessment of the utility of a newly developed camera trap to study the winter dynamics of small mammals in the Low Arctic tundra of northern Norway. Forty functional cameras were motion-triggered 20 172 times between September 2014 and July 2015, mainly by grey-sided voles ( Myodes rufocanus (Sundevall, 1846)), tundra voles ( Microtus oeconomus (Pallas, 1776)), Norwegian lemmings ( Lemmus lemmus (Linnaeus, 1758)) and shrews ( Sorex spp.). These data proved to be suitable for dynamical modelling of species-specific site occupancy rates. The occupancy rates of all recorded species declined sharply and synchronously at the onset of the winter. This decline happened concurrently with changes in the ambient conditions recorded by time-lapse images of snow and water. Our study demonstrates the potential of subnivean camera traps for elucidating novel aspects of year-round dynamics of Arctic small mammal communities. Les petits rongeurs constituent un indicateur clé pour comprendre l’effet du changement rapide du climat hivernal sur les écosystèmes de la toundra arctique. Cependant, le suivi des populations de rongeurs pendant le long hiver arctique au moyen de pièges conventionnels a jusqu’à présent été entravé par la couverture neigeuse et les conditions ambiantes difficiles. Les auteurs réalisent ici la première évaluation approfondie de l’utilité d’un nouveau piège photographique pour étudier la dynamique hivernale des petits mammifères dans la toundra du bas-arctique au nord de la Norvège. Quarante appareils photo fonctionnels ont été déclenchés par le mouvement 20 172 fois entre septembre 2014 et juillet 2015, principalement par des campagnols de Sundevall ( Myodes rufocanus ...