Using Unmanned Aerial Vehicles to Count and Monitor the Baikal Seal (Pusa sibirica Gmelin 1788)

To develop a method for monitoring the condition of Baikal seals (Pusa sibirica Gmelin 1788) and to count their numbers in summer haul-outs using an unmanned aerial vehicle (UAV) in July–August 2020 and 2021 on the islands of Tonkii (Thin), Kruglyi (Round), and Dolgii (Long) (the Ushkan Islands archipelago), visual surveys and surveys with UAVs were carried out. The maximum number of seals observed was 3467 in 2020 and 1295 in 2021, and their total number in 2021 was also lower than in 2020. During both years of observation, the number of seals in the haul-outs gradually decreased, which might be explained by the wave level on the lake. Contrary to the popular belief about the largest seal haul-out located on Tonkii Island, the greatest number of seals was found on Dolgii and Kruglyi islands. Recommendations for the use of UAVs, which can also be useful in developing the rules for tourists visiting the national park, are given.