福建南平一中华菊头蝠种群年龄结构及相关特征

Study on the age structure and some age characteristics of Rhinolophus sinicus from Nanping,Fujian Province,China

采用臼齿磨损度与牙齿牙骨质生长线年龄鉴定法,对福建南平采集的一中华菊头蝠(Rhinolophus sinicus)种群42例成体样本进行年龄结构及相关特征的研究.臼齿磨损度是对左侧第1上臼齿磨损情况进行测量,以臼齿齿冠磨损面的宽度与臼齿外侧牙龈线至中间齿尖的高度之比估算,再根据其分布人为划分4个磨损年龄组.同时对标本左侧第1上犬齿切片进行石蜡包埋切片以观察其牙骨质生长线,用以鉴定其年龄.最后综合比较分析二者结果,探讨了2种方法对年龄鉴定的一致性.结果表明:利用牙齿磨损度推算的蝙蝠年龄与牙齿生长线鉴定的年龄基本一致,但是前者对头骨和牙齿不产生损伤,操作简单方便,是科学可行的鉴定蝙蝠年龄的方法.同时也表明福建南平种群应为稳定型种群,在繁殖期间雌雄比近似1∶1;雌性个体一般在2龄及以后才参与繁殖.此外,主成分分析的结果显示无法通过外形指标和头骨指标对成体中华菊头蝠进行年龄上的区分.

Through an investigation of incremental lines of the dental cementum and estimations of degree of the molar wear,the age structure of a Rhinolophus sinicus population that was sampled from Nanping,Fujian Province was studied in this paper based on 42 adult bats. According to dental observations under a microscope,four different wear age groups were determined based on the degree of the molar wear,which is the ratio of width of middle wearing surface to the height between molar flank gum line and middle crown. After slicing the treated tooth embedded in paraffin,the age of individuals was also identified according to the incremental lines of the dental cementum. It is found that although the results from two different methods were broadly consistent,compared with destructive method based on investigation of incremental lines of the dental cementum,age group determination using the degree of the molar wear would be a better and more feasible way for age identification for bat species. Meanwhile,the age structure of Rh. sinicus population from Nanping,Fujian indicates that it should be stable population; its sex ratio is around 1∶1 in the breeding season; and the females generally do not behave reproductive behavior until two-year-old. In addition,our principal components analyses suggest that it is hard to distinguish different age groups through external and skull measurements.