Where remnants of old native vegetation remain, small nocturnal insectivorous microbats have probably provided agricultural production services by reducing insect populations in two ways: direct predation, and interruptions to reproduction activities by avoidance behaviour adopted at hearing microbat ultrasound echolocation, Many microbat species require roost sites in tree hollows, the selection of which varies interspecifically as well as intraspecifically.

Because little has been known of these production and environmental interrelationships, to assess landscape scale microbat presence and activity patterns, landscape surveys were undertaken across three cotton production properties adjacent to the Namoi River between Narrabri and Wee Waa on the north west plains of NSW.

Using ultrasound recording equipment and a portable weather station, microbat echolocation calls were recorded against seven native vegetation and three intensive management landscape categories, at 102 sites in autumn 2003, and at 64 sites in three seasonal surveys, November, February and April/May, during the 2003/04 cotton season. Recording was conducted between dusk and dawn over seven nights (autumn 2003), and between civil twilight and 12 midnight over eight nights (2003/04 seasonal surveys). Capture of microbats in spring 2003 enabled verification of call species identification.

A tree hollow survey to assess roost site potential was commenced and a pilot study to assess the potential of microbat research as a tool for attitudinal change was undertaken.

If relationships between microbats and cotton production can be demonstrated by this research, the need to support a microbat activity production benefit could provide strong motivation for remnant native vegetation conservation as microbat roost habitat, that could in turn maintain both, ecosystem services and greater sustainability to cotton production, as well as