Methodology comparison of the age structure of Apodemus agrarius population

samples of Apodemus agrarius (150 females and 144 males)were divided into five age groups:young(Ⅰ),subadult(Ⅱ),adult(Ⅲ),adult(Ⅳ)and elder(Ⅴ)based on the developmental degree of molar worn to investigate the changes of body weight,body length and tail length of the different groups during 1999 2000.The results showed that the division based on growth indice including body weight and body length could replace the developmental degree of molar worn in the age division because the fit probabilities between the index based on the body weight and body length and those based on the degree of molar worn were 94 56% and 87 07% respectively.The reproductivity of different groups was also discussed.