关键词: 黄胸鼠, 年龄, 洞庭平原

Abstract: Refer to the reproductive status, Buff-breasted rat (Rattus flavipectus) in Dongting
Lake region was divided into 5 age classes based on body weight without viscera: Age
class I. juvenile, ≤35 g; II. subadu lt, 36～65 g; III. adult I, 66～100 g; IV. adu lt II,
101～135 g; V. o ld, >135 g.
The differences among the body weight without viscera, the body weight, the body
length and tail length between neighboring age class were signif icant.
The body weight of the animals kept increasing in all age classes. The length of body and tail also kept growing from age class I to IV , but the growing rates were not
obvious in age class V.
The females started breeding from age class II and reach peak at age class IV. The
size of test is grew continuously from age class I to IV.
The age distribution fluctuated from January to June, and it was stable relatively
f rom July to December.

Key words: Buff-breasted rat(Rattus flavipectus), Age determination, Dongting, lake region