Mining activity disturbs habitat use of reindeer in Finnmark, Northern Norway

Abstract

Anthropogenic activities affect habitat use by Rangifer tarandus, a particularly vulnerable species due to grouping behavior, extensive movements, and grazing ecology. We studied habitat use of GPS-collared reindeer in relation to surface mining activities during the snow-free season in Finnmark, Norway over a period of 7 years. Based on information about the mine’s level of operation (amount of people, vehicles, and equipment in operation) and rock blasting schedule, we divided data into high-activity periods (workdays) and low-activity periods (mine closed for ca 2.5 days on weekends and a yearly 3-week holiday period). We further divided workdays into periods with and without rock blasting and associated high-noise days. We found that reindeer significantly reduced habitat use at closer distances to the mine, indicating an influence zone up to 1.5 km. Reductions in use were strongest closest to the mine in high-activity periods. No avoidance effect of the mine was found beyond approximately 0.9 km for the 3-week holidays, 1.0 km for weekends, and 1.5 km for workdays with or without rock blasting. Compared to holidays and weekends, probability of use was reduced by 30–34% within 1.3 km from the mine for workday blasting periods, and up to 35% within 1.4 km for other workdays. Since averted areas can be partly utilized again within days or weeks following intensive mining activity periods, reduced mining activity in crucial periods for reindeer, such as during calving and migration, can be an effective mitigation measure.