Introduction

Presently, methods commonly used for bat identification and population study are intrusive and require the capture of bats. Using a Light Detection and Ranging (LIDAR) laser scanner, we successfully developed a novel nonintrusive method to remotely identify and measure the population of roosting bats in caves. The scans successfully captured 3D features of the roosting bats, their spatial distribution pattern and provide 3D spatial roosting data that are amenable for spatial and statistical analysis. This novel method allows researchers to study roosting behavior such as maternity roosting patterns, roost sharing and roost-switching patterns within the topographical context of the speleological (caves, subterranean spaces and caverns) internal surface, making rigorous quantitative characterizations of cave roosting possible.


Current Project

Bat population survey using terrestrial laser scanning at Gua Kelawar, Langkawi

A survey aims to obtained the population size of bats has been conducted in Gua Kelawar on 12th of July 2011 from 12 pm to 6 pm. This survey also conducted to identify the species of bats roosting in this cave. Several methodologies were applied in this survey.


Scan Result

From the result of the cave scan, there are 1520 individuals of bat counted from the model. However as a comparison, direct counting of the bats from image showed 1284 individuals. It can be seen quite a difference between results from both methods. Images produced from the cave scanning and some of the species detected in Gua Kelawar can be viewed in the Galleries.

 

Bat Counting

This result are compared to survey done by Norhayati,A., Shukor Md. Nor, Shahrul Anuar, M.S., Nurul Ain, E. & Norzalipah, M. on 12 April 2003. The method use in that study is photo capturing and counting per hour from 0800 to 1700 and 1900 to 0600. The table below shows the result obtained from that study.

Total Population Day(0800h-1700h) Night(1900h-0600h)
Number of individual bat according to time 4595 1518
Mean population 765.8 151.8
Standard error 32.7 27.4
Median 785 136
Standard Deviation 80.1 86.6
Minimum 616 68
Maximum 843 347

Total bat counting on 2003 is 766 individuals