Satellite telemetry uncovers important wintering areas for Snowy owls on the Kola peninsula, northwestern Russia

Abstract

In order to reveal winter movements and wintering areas of snowy owls breeding in Northern Fennoscandia, we conducted a telemetry study by use of battery operated satellite transmitters. Nine battery powered ARGOS satellite transmitters that we deployed on snowy owls in Norway in 2007, 2011 and 2015 provided data at least one full winter for altogether 21 individual winter periods. The snowy owls arrived in their wintering grounds on average on 10th November and stayed until 13th April, while the average number of days spent wintering was 156. The snowy owls showed extensive mobility as each tracked individual travelled an average distance of 991 km on medium and long-distance movements during each individual winter period. We revealed a great flexibility in the choice of wintering sites among snowy owls, which we consider to be a response to prey availability, and we assume that they mainly exploit ptarmigan species as food source during winter. All nine instrumented owls spent at least part of one of their tracked winters in the northern and eastern part of the Kola Peninsula, and six of the nine tracked snowy owls spent 100% of at least one of their winters there. More than 50% of the time in the 21 individual winter periods were spent in the northern and eastern interior parts of the Kola Peninsula. As the snowy owl is a globally threatened species, these results are potentially of great importance for the conservation of the species.