Abstract
Several methods on the estimation of population size of animals are discussed. The method of capture-recapture is popular in mathematical statistics. Besidesthis, other methods are introduced. Particulary, the track method and operational method by the author are explained in detail. The contents are as follows; 1) Capture method, 2) Observation method, 3) Capture-recapture method, 4) Method based on home range, 5) Track method, 6) Interval method, 7) Operational method.
