Radio-tracking a rare bat

The Airly Mine near Capertee in NSW is an underground coal mine with relatively small on-ground footprint immediately adjacent to several National Parks and reserves. For a number of years, the mine has run a comprehensive environmental monitoring program, thanks to the University of Queensland’s Centre for Mined Land Rehabilitation (CMLR). In October this year, CLMR took their monitoring to a new level with the help of Bruce Thomson (mircobat expert, Redleaf Environmental) by investigating various aspects of the ecology of a rare bat that occurs in the region, the Large-eared Pied Bat (Chalinolobus dwyeri).  In previous surveys, a number of old mines had been regularly monitored for other bats; the Eastern Horseshoe Bat and Eastern Bent-wing Bat, but the behaviour of this additional species, which is regarded as a threatened species under both Commonwealth and NSW legislation, had remained something of a mystery.

In October this year, Bruce who is an Industry Fellow with CLMR and Elizabeth Williams, conducted some radio telemetry work, tracking male and female C. dwyeri to locate their roosts and also gain some insights into foraging areas. The location of roost sites was particularly important in terms of understanding the potential impact of mining operations in the area. This species is known to use shallow caves for maternity sites, but did these bats follow the same patterns as observed elsewhere and were any of the maternity sites near the mining operation?

Bruce said, "What we found was that yes, both males and females roosted in the sandstone escarpments and tended to regularly occupy the same general area. They also moved roost sites over the week-long study period and all of the roosts were on vertical rock faces and so were not possible to access."

"Foraging occurred primarily in the dry eucalypt forests adjacent to the roost sites, but early indications from the telemetry data suggested that they may also forage over nearby cleared land that is currently part of a grazing lease."

"This is the first time that such a study has been conducted on this species and a good deal more work is required to fully explore their habitat use in the area. A second trip is now planned for mid-December to locate further roost sites and to confirm foraging activity over the open pasture lands."

From what has been discovered so far, it seems highly unlikely that mine will have any impact at all, on this species, so that’s a very positive outcome from the project.