Je. Swenson et al., A POTENTIAL METHOD FOR AGE-DETERMINATION OF THE CHINESE GROUSE BONASA-SEWERZOWI, Journal fur Ornithologie, 137(2), 1996, pp. 253-257
Based on examination of 38 specimens of the Chinese Grouse, and age de
termination methodes described for the Hazel Grouse, we suggest a pote
ntial age determination technique for the northern subspecies of the C
hinese Grouse (B. s. sewerzowi). Adults appear to have a distinct boun
dary on the tip of P1 and juveniles a diffuse boundary. Adults may dom
inate in the group with > 6 dark bars on P9. This technique does not s
eem to be applicable to the southern subspecies (B. s. secunda). We en
courage further testing of this potential method.