Importance & Need
Bat reference calls, also known as voucher calls, are acoustic recordings of bat echolocations, social calls, etc. where the identity of the recorded species is established through reliable non-acoustic identification methods, i.e., capture, genetics, etc.
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Bats are cryptic, nocturnal creatures that can be incredibly difficult to study. Acoustic monitoring allows us to passively and noninvasively monitor bats and bat populations, even in remote locations. Nonetheless, the structure, frequency and temporal pattern of bat vocalizations (referred to here as "call") can vary dramatically even within a given species due to the surrounding habitat, presence of other bats, life stage of the bat, etc. Conversely, different bat species can have overlapping call characteristics that make species-level identification difficult or unreliable despite major advances in automated classification algorithms and software.
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​​​Despite the NABat database representing over 130 million bat acoustic records (and counting), there is still a pressing need for verified, curated reference recordings, particularly for underrepresented geographies and species. These bat reference calls are needed to help improve the utility and reliability of acoustic monitoring as a tool for studying bats and are essential for advancing our understanding of how species and populations are faring across North America. ​​
General Recording Guidance
General Best Practices for Recording High Quality Bat Reference Calls​​
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Use low-intensity spotlight to track target bat and orient microphone for recording.
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​Avoid recording in areas with high bat activity (e.g., adjacent to ponds, cattle troughs) to reduce risk of recording nontarget individuals.
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Avoid recording in proximity to other captured bats.
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Light tags can be used to effectively track released bats (avoid tags that exceed 5% of body weight; consult local USFWS office for permission to light tag listed species as part of a federal permit).​
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Note: NABat discourages submitting recordings not verified via reliable non-acoustic methods.
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Embedding Metadata to Files
1. Currently, NABat Reference Call Metadata can be embedded to audio files using a custom NABat xml form in the Kaleidoscope Lite (no subscription required) or Kaleidoscope Pro (subscription required) softwares. Open Kaleidoscope Lite/Pro. Confirm you are in Bat Analysis mode in the Batch tab (this allows for processing of WAV or ZC files). Under the INPUTS section click Browse to select the Input directory of the folder containing your .wav/.zc files. Select the box beside the type of input files (WAV files or ZC files).​
​2. Click the drop-down menu above the Default Project Form and select Add or Replace a Project Form. Navigate to NABat Reference Call Metadata .xml and select the file. The NABat metadata form will load beneath the drop-down.
3. It is recommended that you organize your reference recording files into folder(s) grouped by SURVEY EVENT and SPECIES (at a minimum) prior to proceeding with the metadata embed process. Grouping files to maximize shared attributes across the metadata fields minimizes the need for post-hoc edits. This may necessitate using input directories that house only a single file.
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Download the required NABat Reference Call Metadata xml here.
​4. Complete all metadata fields for which you have uniform data across all Input directory files. Leave field responses blank and manually edit metadata in resulting meta.csv outside of this application (i.e., in Excel) for any fields that may differ across audio files within your Input directory (e.g., same Reference Species ID across all recordings but Audio Recording Characteristics differ). Note, edits to the meta.csv made outside of this application will not be embedded to the audio files. NABat required metadata fields include:
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GRTS Cell ID or Latitude and Longitude
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Site Name
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Audio Recording Date
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Audio Recording Name
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Reference Species ID
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Species ID Method
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Surveyor(s)
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Microphone Model
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Recording Scenario
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Submitted to Software Developer(s)?
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​5. Once all required metadata fields and any additional fields for which you have data have been completed, select the desired output directory to save processed files by clicking Browse in the top right of the window.
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6. Once the output directory has been selected, choose None from the Create subdirectories drop-down menu and select the type of output files you intend to create, WAV or ZC (ZC files cannot be converted to WAV).
7. Finally, click the Auto ID for Bats tab at the top of the window and confirm that your classifier is DISABLED (only Kaleidoscope Pro subscribers have access to Auto ID for Bats).
8. Click Process Files in the bottom right corner of the window.
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Finalizing Metadata
1. Open Output directory folder to view processed (metadata embedded) files. Locate and open the meta.csv.
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2. Manually complete any necessary metadata adds or edits for field responses that differed across recordings. Note, these edits will not be embedded in the audio files.
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3. Rename the meta.csv file with a descriptive and unique name and save. The NABat system will automatically overwrite duplicate file names with the most recent version, so it is critical that your file name is unique. Example: SiteName_SpeciesCode_ReferenceCalls_YearMonthDate.
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