Prepared by Martin Schulz and Linda F. Lumsden
Department of the Environment and Heritage, 2004
ISBN 0 642 55012 3
Appendix four: Summary of recent information indicating further range and population decline
This Appendix provides a summary of recent information indicating a continuing decline and range contraction in the species.
A. Greg Richards, Bat Consultant (pers. comm.)
For more detailed information refer to the fauna survey as part of the EIS of the Mine Lease Applications & National Park Reference Areas conducted in August 2002 for Phosphate Resources Limited by EWL Sciences Pty Ltd.
Evidence indicating a significant reduction in abundance using ultrasonic data as an index of abundance. Using similar methodology to Lumsden et al. (1999) the Christmas Island Pipistrelle data collected by G. Richards indicated:
- the species was recorded in less sites than in 1998;
- the species had undergone a further westward range contraction on the island;
- there were a decreased number of bat passes at most sites; and
- the species was only recorded foraging in four localities.
B. David James, PAN (pers. comm.)
The following information was provided by David James: In February and March 2004 searches for the Christmas Island Pipistrelle were undertaken using Anabat detectors and harp traps. Using the detector driving technique outlined in Lumsden et al. (1999) and detailed in Appendix 2, twelve hours of driving at 20 kph over five nights were undertaken on roads and tracks from the South West Baseline to Winifred Beach, approximately 250km total. There was only one site that Pipistrelles were recorded at in any numbers - at the start of the Winifred Beach Track, which was the area with the highest levels of activity in the 1998 surveys. In the 12 hours of sampling, bats were detected at only three other locations, and each time by only a single animal. No bats were recorded at many of the sites where they were regularly recorded in 1998. Harp traps have been set in a number of locations on the island, but the only site that bats have been trapped is the site on Winifred Beach Track.
The level of recording by David James appears to be considerably lower than during the 1998 study.
This recent evidence indicates that a review of the conservation status is required. The species appears to have markedly declined since 1998 and there may be few localities where viable populations remain on the island.