MORPHOLOGICAL-DIFFERENTIATION AND IDENTIFICATION OF PEROMYSCUS-LEUCOPUS AND P-MANICULATUS IN NORTHEASTERN NORTH-AMERICA

External features of the tail and pelage, and quantitative cranial cha racteristics were used to discriminate Peromyscus leucopus from P. man iculatus (n = 204) from northeastern North America. Species assignment s were based on the phenotype of salivary amylase. Characteristics of the pelage and tail yielded correct identification of 55% of adult spe cimens. A previously published discriminant-function equation based on 11 cranial measurements correctly classified 66% of adults and 56% of specimens of all age classes. Two new discriminant equations were gen erated based on 12 and 11 skull measurements, respectively. The first equation correctly classified 100% of skulls in two separate datasets (n = 164; n = 50), and the second correctly classified 94% in a single dataset (n = 195).