Passive Survey
A passive survey is where you place detectors unattended in the field to record. (advantages and disadvantages chart)
Peak frequency
The frequency at which the call reaches maximum amplitude (the frequency of the loudest part of the call). This may be different to the characterstic frequency, as peak frequency is calculated from the full spectrum data, while characteristic frequency is a zero crossing metric.
Pulse
A single echolocation pulse emitted from a bat
Quasi-Constant Frequency (qCF)
Sometimes used to describe FM calls that have very low slope throughout (i.e. they are almost flat). qCF is sometimes used in combination with FM to better describe different types of FM calls (e.g. a FM-qCF call starts with a steep initial FM sweep and ends in an almost-flat FM sweep)
Recording Window
Also known as a Trigger Window. This is the minimum amount of time that the recording will continue after a trigger event. Set this to be longer than the longest time between bat pulses in calls that you expect to record. This will prevent a bat pass being broken up into multiple files.
Sample Rate
How many ‘samples per second’ are taken (measured in ksps). The recommended sample rate will depend on the highest frequency bat you want to record. The sample rate should be at least double the highest frequency bat of interest. Note that higher sample rates require more storage space on the SD card. It’s also worth […]
Schedule Recording Mode
The schedule recording mode allows you to set a custom recording schedule on the detector or computer. You can set a schedule based on sunset/sunrise times or on absolute times.
Shape
In echolocation pulses, shape refers to the two-dimensional curve formed when plotting the change in frequency against time throughout the pulse.
Slope
May be used as a qualitative descriptor for the pulse slope (e.g. “steep” or “flat”) or measured (eg. Characteristic Slope)
Social calling
In addition to their echolocation signals, bats also produce ultrasonic and audible social calls that serve as a means of communication and convey social information. These social calls are different from typical echolocation calls. Bats commonly emit social calls when near a roost, during periods when sub-adults are learning to fly or forage, or when […]