Once you’ve found a call of interest, listening to it will hopefully provide the identity. But it is surprising how many nocturnal calls are unfamiliar. Add the fact that calls may be distant or obscured by urban noise pollution or those cursed night-singing Robins, and identification may not be straightforward. So what are your options? The website xeno-canto is essential listening (see below), some nocturnal calls are listed on the birds-in-flight website, and the Sound Approach offers cutting edge ID discussion.

For common nocturnal migrants try our simple Call Guide.

If your recording doesn’t match anything below, try loading your mystery recordings to e.g. SoundCloud, then sharing them on Twitter using #nocmig.

Getting the most from xeno-canto

The website xeno-canto  is a must for identifying tricky recordings, though it helps to have an idea of species to check to direct your search. Search for a species then use the Filter box under the map to focus on nocturnal recordings (enter rmk: nocturnal) or flight calls (enter type: flight).

xeno-canto results filtered to show nocturnal recordings


By default a list of recordings is shown, but click the sonograms link above the header to view spectrograms of all the recordings. Note these only show the first 10 seconds of each clip. For really tricky identifications you may need to download the xeno-canto recording and open it in Audacity. Then you can select, copy and paste individual calls from these reference recordings and line them up next to your own to view them on the same scale. But remember to check the metadata associated with recordings – identifications are not always verified by the recordist seeing the bird and some errors may exist.