Seven Kinds Of Ecological Study Of Bat Echolocation Behavior

The echolocation of bats is a major field in the research of bats. The characteristics of calls are closely correlated to the ecology of bats, for example, the dominant frequency influences the body size of bats' prey, the detecting range of bats; the structure of calls decides bats' ability to detect prey in the complicated environment. Therefore, the research on factors, which influence the structure and characteristics of ultrasound and on the mechanism by which bats detect and orient the prey will promote the understanding of the ecological behavior of bats. The emission and receiving of calls are not only influenced by the sound-emitting apparatus and sound-receiving apparatus, but also by the body size, age, state and foraging stages of bats.The echolocation calls detector (D980, ULTRASOUND DETECTOR, Pettersson Elektronik AB, Sweden) and digital recorder (SONY, TCD-D8) were used to record the calls and the software Batsound 3.10 (Pettersson Elektronik AB, Sweden) was used to analyze the calls. The morphological features were measured with the ruler, vernier caliper and balance. The software SPSS 11.5 was adopted to compute and analyze the data.The characteristics of echolocating calls of R.yunanensis, R.macrotis, H.pratti and H.bicolor were analyzed and described; it is the first time in China to do this kind of research. R.yunanensis is native to China, so the research on its echolocation is characteristic of China and provides new data to set up the echolocating calls database in the world. The bat mother and its child were compared concerning their morphology and echolocating calls, and the change in morphology and echolocating calls, which happened as the young bat grew were discussed. The communicating behavior between the mother and the young was described and thus the calls played an important role in the communication betweenthe mother and the young. The echolocating calls in the state of fly were compared with those in the state of hang in two kinds of bats, R.yunanensis and H.pratti,and the Doppler Compensation Effect was described. The analyzing result indicated that the frequency in hang was higher that that in fly, the duration and interpulse duration in hang were longer than those in fly, and the FM bandwidth in hang was narrower than that in fly. The difference in morphology and echolocating calls of female and male individuals was analyzed in three kinds of bats, R.cornutus, A.wheeleeri and H.armiger. The result showed that there was no significant difference in morphology, but there was significant difference in echolocating calls between the two sexes in all the three kinds of bats. The significant difference in calls may be caused by the work division or communication in the colony of bats, as bats are animals which are adapted to aggregation life.