Anyone who has sat beside a mist net knows that most bats that approach the net avoid it, and many others just fly by out of its reach. What bats are those? Well, those bats may avoid the net, but they don't avoid emitting echolcation calls that you can automatically record with a bat detector and analyze using SonoBat.
Certainly there are reasons to capture bats, e.g., to attach radio tags for tracking. But for a goal of species presence, digital mist netting offers an easier and typically more effective solution, and with dire concerns for bat welfare from White Nose Syndrome, noninvasive acoustic monitoring becomes a better and better solution.
Longer term recording arrangements are possible with higher capacity units such as the Pettersson D500x, WIldlife Acoustics SM2BAT, or the Binary Acoustic Technology AR125 together with an FR125. These and other recording solutions can be configured to record at specified times, autotrigger, and write files with a date and time stamps, and record direct to digital memory without interruption as with previous generation detectors that slowed data throughput with time expansion.
WIldlife Acoustics SM2BAT detector.
However, simpler solutions still provide very useful data.
Samson Zoom H2 recorders provide a simple way to time and date stamped files for single night recording. View this PowerPoint guide for Zoom H2 recording. Although ideal for wildlife recording, iriver no longer produces the IFP series units. However, they can still be purchased through outlets such as ebay. Newer models limit recording capability, most likely over concerns regarding music copyright infringement. Other digital recording products to consider include the Samson Zoom H2 and the Edirol R-1. See the AutoParser and AutoRecorder pages to use other recorders.
See also this page about recording advice and suggestions for long term recording.
The SonoBat Batch Attributer utility can attach notes, attributes, and site-specific filenames to your AutoRecorded files.
Above: labor intensive setup, and misses many bats.
Below: easy set up, and records all bats that fly by.
Pettersson D500x in survey pouch.
Binary Acoustic Technology AR125.