University of Oulu

Pedersen, S.H., Bentzen, T.W., Reinking, A.K. et al. Quantifying effects of snow depth on caribou winter range selection and movement in Arctic Alaska. Mov Ecol 9, 48 (2021).

Quantifying effects of snow depth on caribou winter range selection and movement in Arctic Alaska

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Author: Højlund Pedersen, Stine1,2; Bentzen, Torsten W.3; Reinking, Adele K.2;
Organizations: 1Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, 99508, USA
2Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO, 80523, USA
3Alaska Department of Fish and Game, Fairbanks, AK, 99701, USA
4US Forest Service, Rocky Mountain Research Station, Fort Collins, CO, 80526, USA
5ABR, Inc.—Environmental Research & Services, Fairbanks, AK, 99708, USA
6Ecology and Genetics Research Unit, University of Oulu, 90014, Oulu, Finland
7UArctic, University of the Arctic, 96101, Rovaniemi, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 7.4 MB)
Persistent link:
Language: English
Published: Springer Nature, 2021
Publish Date: 2021-10-05


Background: Caribou and reindeer across the Arctic spend more than two thirds of their lives moving in snow. Yet snow-specific mechanisms driving their winter ecology and potentially influencing herd health and movement patterns are not well known. Integrative research coupling snow and wildlife sciences using observations, models, and wildlife tracking technologies can help fill this knowledge void.

Methods: Here, we quantified the effects of snow depth on caribou winter range selection and movement. We used location data of Central Arctic Herd (CAH) caribou in Arctic Alaska collected from 2014 to 2020 and spatially distributed and temporally evolving snow depth data produced by SnowModel. These landscape-scale (90 m), daily snow depth data reproduced the observed spatial snow-depth variability across typical areal extents occupied by a wintering caribou during a 24-h period.

Results: We found that fall snow depths encountered by the herd north of the Brooks Range exerted a strong influence on selection of two distinct winter range locations. In winters with relatively shallow fall snow depth (2016/17, 2018/19, and 2019/20), the majority of the CAH wintered on the tundra north of the Brooks Range mountains. In contrast, during the winters with relatively deep fall snow depth (2014/15, 2015/16, and 2017/18), the majority of the CAH caribou wintered in the mountainous boreal forest south of the Brooks Range. Long-term (19 winters; 2001–2020) monitoring of CAH caribou winter distributions confirmed this relationship. Additionally, snow depth affected movement and selection differently within these two habitats: in the mountainous boreal forest, caribou avoided areas with deeper snow, but when on the tundra, snow depth did not trigger significant deep-snow avoidance. In both wintering habitats, CAH caribou selected areas with higher lichen abundance, and they moved significantly slower when encountering deeper snow.

Conclusions: In general, our findings indicate that regional-scale selection of winter range is influenced by snow depth at or prior to fall migration. During winter, daily decision-making within the winter range is driven largely by snow depth. This integrative approach of coupling snow and wildlife observations with snow-evolution and caribou-movement modeling to quantify the multi-facetted effects of snow on wildlife ecology is applicable to caribou and reindeer herds throughout the Arctic.

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Series: Movement ecology
ISSN: 2051-3933
ISSN-E: 2051-3933
ISSN-L: 2051-3933
Volume: 9
Article number: 48
DOI: 10.1186/s40462-021-00276-4
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Funding: This research was funded by United States National Science Foundation grants 1604249, 1602898, and 1839198; National Aeronautics and Space Administration grant 80NSSC18K0571; and JMW’s UArctic Research Chair position.
Copyright information: © The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.