How to upload bat records to iNaturalist

The iNaturalist app and website allows anyone to add biological records to a vast database. By its nature, this is an unstructured survey, and the random nature of observers and their locations means this data cannot be used to quantify species abundance or indicate their absence.

However, the iNaturalist records can be used to indicate the presence of a species.

iNaturalist allows for the verification of records by others based on the evidence uploaded. The bat flight records uploaded on the night of a Big Bat Count are classed as “casual” records as they have no evidence that allows them to be verified. People using the default settings of iNaturalist will not see these “casual” records. Hence the bat group has created specific iNaturalist projects to allow anyone to view them:

To verify bat records, after the count night, the bat group can upload an observation that includes at least the original .wav recording of the bat echolocation, and preferably images of the spectrogram of that call.

The problem

Bat recordings (from an Echo Meter Touch (EMT) or other devices) are hard to manually upload to iNaturalist. It is tailored towards uploads of photos of wildlife, and it works superbly at this.

Suppose you upload an observation that includes either an original wav file or a screenshot of a bat call spectrogram. In that case, you have to manually enter all the metadata, including species, date and time, location and any notes.

Including the spectrogram screenshot, and truncating the wav file, all this takes about 10 minutes per bat record and is not a practical process if you need to upload dozens of bat records.

A solution

Dr Tom August from the Biological Record Centre has created a website called Bat2iNat to solve this problem of upload of EMT recordings to iNaturalist.

This logs into iNaturalist using your ID and allows multiple wav files to be uploaded as a batch. As the batch is processed Bat2iNat extracts the metadata (in GUANO format) from the EMT wav file and processes this to automatically add a new iNaturalist record that includes:

  • Species name (taken from the filename, Bat2iNat does not AutoId species)
  • Date and time
  • GPS location
  • An overview spectrogram of the bat call
  • A zoomed in close up spectrogram of the bat call
  • A version of the original wav file truncated to the bat call section
  • The notes section is populated with:
    • Recorder model and version
    • The number of good quality calls:
    • Av. peak frequency (kHz):
    • Av. max frequency (kHz):
    • Av. min frequency (kHz):
    • Call durations (ms):
    • Recorder settings

During our meeting, Tom stressed that Bat2iNat does not save or record iNaturalist login IDs (you have to log in every time) and that the code is open source on GitHub so anyone can verify this.

How to upload using Bat2iNat

Currently, Tom is trailing Bat2iNat so he has only granted access to certain iNaturalist IDs. Hence for now we are reusing one SBG iNat account for uploading.

What to upload?

The first job is to decide what to upload by reviewing the recordings you have made, to select the best ones. Select wav files that are:

  • A clear distinct recording of the echolocation call
  • Not too noisy, and doesn’t have anything inappropriate recorded!
  • Only one species. Bat2iNat only works if one species of bat is present in the recording.
  • Not duplicates. As we are just trying to indicate species presence, do not upload more than one or two calls per species from an area, or night.
  • Complete metadata; including GPS location, and correct species in the filename

How to upload using Bat2iNat

  1. Load the webpage of the app:
  2. It can take a little while to load as the server puts the app to sleep when it’s not being used and waking it up takes about 30 seconds.
  3. Log in with these credentials:
    • Username = sbgupload
    • Password = the name of the county town in Somerset, all in lowercase
  4. Click “I Agree” to the agreement.
  5. Browse to select the desired wav files (max size 10MB each)
  6. Once selected, the magic happens. The files are uploaded, processed, and if successful, added as observations in iNaturalist.
  7. The list of observations added is shown below the browse box. As the iNaturalist website seems to lag in updating, the easiest way to view the new records is to use the button in Bat2iNat.
  8. You can then check the records in iNaturalist, and edit if required to add anything, or add to the notes things such as “Recorded by “your_username”“, or “Recorded along a mature mixed hedge near the river“.

How often should we upload records to iNaturalist?

iNaturalist relies on the community for verification of records, hence it is important not to annoy people by uploading too many similar records.

As a guide for each survey location, we suggest only uploading one or two flight records for each species, every quarter, i.e once in spring, summer and autumn.