扁颅蝠与褐扁颅蝠的集群结构

2001—2002年在广西宁明县和龙州县利用直接观察、捕捉测量(共捕到197群蝙蝠，全捕180群)和标记重捕法(标记了31群的101只扁颅蝠，重捕到36只)比较研究了扁颅蝠(tylonycteris pachypusa)与褐扁颅蝠(T．robustula)的集群结构。结果发现：扁颅蝠与褐扁颅蝠主要栖宿在刺竹(Bambusa stenostachya)的竹筒内，通过竹筒上的裂缝进出。扁颅蝠栖宿的竹筒长平均为27．7cm，外围直径平均为23．6cm；褐扁颅蝠的分别为28．3cm和23．8cm。扁颅蝠栖宿群大小为1—24只，褐扁颅蝠栖宿群大小为1—13只；2种蝙蝠的栖宿群中皆为独居所占比例最大(扁颅蝠为22．30％，褐扁颅蝠为40．63％)，2只所占比例次之(分别为14．87％和18．75％)，其它大小类型呈不规则变化。扁颅蝠栖宿群的性别组成，以雌雄混居最常见(占54．72％)，其次为独居雄性(占20．95％)，而褐扁颅蝠栖宿群雌雄混居群与独居雄性所占比例相当(均为40．63％)。2种蝙蝠的雄性趋向于独居，而雌性趋向于群居。扁颅蝠与褐扁颅蝠可以栖宿在同一片竹林内，并且可以在不同时间轮流使用同一个栖宿竹筒，但2种蝙蝠从未共栖于同一个竹筒内。另外，标记重捕扁颅蝠发现：扁颅蝠经常变换栖宿竹筒(栖宿竹筒不固定)；同时栖宿群之间经常发生个体交换动物学报50(3)：326—333．2004]。

Group structure of lesser flat-headed bat Tylonycteris pachypusa and greater flat-headed bat T.robustula

We studied the group roosting structure of the two species of flat headed bats Tylonycteris pachypus and T. robustula in Guangxi, South China, using direct observation, catching and measuring (total 197 groups, 180 groups were complete catched), marking technique (marked 31 groups, total 101 individuals of T. pachypus, re captured 36 banding bats). Both bat species roost within the internodes of one bamboo species Bambusa stenostachya . They enter and leave the internodes through narrow slits. The length of internode averages 27 7 cm for T. pachypus and 28 3 cm for T. robustula , the outside diameter averages 23 6 cm for T. pachypus and 23 8 cm for T. robustula. Among 180 roosting groups studied (148 for T. pachypus and 32 for T. robustula) , the roosting group size within each internode from 1 to 24 for T. pachypus and from 1 to 13 for T. robustula. However, the roosting group size of 1 or 2 was most frequently encountered (22 30% and 14 87% for T. pachypus , 40 63% and 18 75% for T. robustula ). The roosting group of most T. pachypus either contained both males and females (54 72%) or solitary male (20 95%). The percent of these two types of roosting groups occurred were both 40 63% for T. robustula . In both species, males tend to roost solitarily while females gregariously. Although both bat species roosted in the same bamboo area, they roosted within the same internode at different times. Both bat species never roosted within the same internode at the same time. This finding suggests a partition mechanism for roosting between the two bat species. Based on banding and recapture data for 101 T. pachypus, we found that most bats were recaptured within one month and recapture rate was higher in female (41 82%) than in male (28 26%). In addition, they were highly mobile and frequently changed roosting site with ephemeral roosting association.