We measured: 1) mean calling rate (total number of vocalizations divided by observation time); 2) maximum calling rate (the highest value of calling rate obtained by dividing total observation per 1 min consecutive intervals); 3) minimum calling rate (the lowest value of calling rate obtained by dividing total observation per 1 min consecutive intervals); 4) call rate range (difference between maximum and minimum calling rates); 5) min with vocal activity (number of min in which the focal male called at least once); 6) vocal behavior category (constant callers: if the focal male called at least once in every 1 min consecutive intervals during the observation; silent: if the focal male did not call during the observation; and inconsistent callers: all cases between constant callers and silent males); 7) locomotion (summed number of events of jumping, walking, and swimming); and 8) adjustments of position (number of events of small movements that do not result in locomotion).