In the transition towards the bottom right corner
(Table 3, Fig. 8), where the dynamics in landscape use
are of interest, we are dealing with a larger scale and less
resolution in time. Rather than more sophisticated processing
of ultrasound, key factors involve the number of
sample points in a landscape and the intensity and cost
effectiveness with which samples can be collected,
either automatically or manually. In manual surveys
involving transects or sample points, a successful
approach can involve multiple observers with heterodyne
detectors. Where automated sampling is
employed, relatively simple, stationary, automated setups
with heterodyne detectors and signal-activated
recorders can be effective. Both manual and automated
surveys should be supported by some sets of time-expansion
or frequency-division recordings for back-up analysis
and verification of the composition of the bat fauna.