Corregidor-Castro A, Holm TE, Bregnballe T. Counting breeding gulls with unmanned aerial vehicles: camera quality and flying height affects precision of a semi-automatic counting method. Ornis Fenn [Internet]. 2021Mar.31 [cited 2024Nov.21];98(1):33–45. Available from: https://ornisfennica.journal.fi/article/view/133979