BCM's Top Recommendation for Active Recording:
Active surveys give you the best quality and longest call sequences as you track the bat with a directional microphone. You witness first hand not only where the bats are, but what they are doing at the time of recording, and maybe even visually identify what species. The best way to learn a bats repertoire is by recording the bats you catch and professionally identify during your regular surveys, then recording the bat calls some time after the bat is released.
This device offers the highest full spectrum sampling frequency of any USB powered ultrasonic microphone (500 kHz) which nudges out our runner up choice, Binary Acoustic Technologies AR125. Batsound Touch, a newly released capture software for Win 7/8 tablets, netbooks, & laptops, offers a bit more functionality than the 2014 version of BAT's Spect'r capture software, and far more functionality than Wildlife Acoustics Echometer Touch offering with it's significantly lower sample rate and undesirable omnidirectional microphone for active monitoring applications. The M500 is built upon the D500x external microphone, and therefore already enjoys the reputation of being part of a well established, well tested microphone family. The Pettersson (and Binary Acoustics Technology) microphones must pass a rigorous quality control/quality assurance before they leave the shop, providing high quality and consistency between units that has not been found in other manufacturer's offerings.
What do you need?
Above: Light tagging a silver haired bat (Lasiurus noctavgans) at BCM's Arizona Study Techniques Workshop in 2014.The best way to learn a bats repertoire is by recording the bats you catch and professionally identify during your regular surveys, then recording the bat calls some time after the bat is released. The easiest way to accomplish this is to place a light tag on the bat, spotlight it, or track it thru a nightvision scope, then record it for as long as it stays in the area. And of course you need to be able to definitely track the exact recording you make to be able to attribute it to a specific bat pass. This is a very costly, time consuming endeavor that relatively few people in the world pursue, and even fewer are good at, but it is nevertheless one of the key techniques used to create libraries of bat calls which may then be used to compare unknown bat calls to. Photo by John Chenger.
BCM's Comparison Chart for Active Monitoring
a.k.a Detectors suitable for visualizing bat calls in real time
See also: BCM's top pick for: