Nocturnal Flight Call FAQs
This is part of the LycoBirds Guide to Recording Nocturnal Flight Calls by David Brown
Here are the answers to some common questions you might have about my setup, and about recording nocturnal flight calls in general. If you have additional questions, please email me at DavidEBrownPA@gmail.com.
Where are you located?
Montoursville, Pennsylvania (Lycoming County)
How much do you hear?
I live in a town in a valley, with a small airport a mile to the south and a highway a mile to the north. Nothing about my location makes it especially good for migrating birds but I hear a lot. On nights of strong migrations I have recorded thousands of calls.
What time of year should I listen?
The most calls can be heard during spring and fall migration. In the summer I still record a few calls per night of local birds such cuckoos, herons, and killdeer.
What time of night should I listen?
I get calls at all times of the night. Start and stop times are often determined by when local diurnal species are vocalizing. In spring and summer my local robin usually wakes up at 4AM (with eerie precision). The descent of thrushes in the pre-dawn hours of a fall morning is hard to beat if you are looking for a specific time to give it a try.
How can I tell when migration is good?
Migration is usually best on nights with favorable winds especially after a weather front moves through. Concentrations of migrating birds show up on weather radar. The NWS Enhanced Radar Mosaic Loop is a good one to use.
What types of birds do you hear?
Thrushes are extremely common and are relatively easy to identify to species. Warblers, sparrows, and many other songbirds are higher in pitch and are more difficult to identify to species. Flocks of geese and swans often migrate at night and so do shorebirds. Cuckoos are extremely common, even during the summer. Local birds such as crows and robins sometimes call at night as well, probably when disturbed.
What rare birds have you recorded?
One night I recorded 3 flocks of brants. Rare shorebirds have included black-bellied plover, dunlin, short-billed dowitcher, and whimbrel. I've also recorded a barn owl. I recorded a number of dickcissel calls during the 2017 irruption.
What equipment do I need for a home station?
- Microphone
- Audio recorder (or computer) for recording
- Cable to run from the microphone to the recorder
- Computer with software to analyze the calls
- Speakers or headphones if you want to listen
How much did your station cost?
- Old Bird 21c (comes with all cables and accessories): ~$300
- Sony PCM-M10 audio recorder: ~$300 (no longer manufactured)
- Speakers: ~$40
- Software: Free
How loud should I set the record level?
Most calls are not much louder than the background noise so the record level can be set fairly high. When a car drives by or a plane lands I know the audio will be overdriven and distort and no calls will be heard during those few seconds. I occasionally get very loud calls, such as from low green herons, that are too loud for my settings, but that is necessary in order to maximize the number of faint calls I can record.
How can I listen without having a permanent station?
Loud nocturnal flight calls can be heard without any equipment. You can use an audio recorder (such as the PCM-M10) with headphones to hear fainter calls, using either the built-in microphones or an external shotgun microphone. The Old Bird 21c microphone can also be set up temporarily if you don't want to permanently install it.
What resources do you recommend for identifying calls?
"Flight Calls of Migratory Birds" from Bill Evans and Michael O'Brien. Unfortunately, this is out of print but the Old Bird website mentions a new edition coming out in late 2017. The Old Bird website has a spectrogram library page with examples.
Update: "Flight Calls of Migratory Birds" is now available for free online.
Appendix for "Acoustic Monitoring of Nocturnally Migrating Birds Accurately Predicts the Timing and Magnitude of Migration Through the Great Lakes" by Claire E. Sanders and Daniel J. Mennill
The Peterson Field Guide to Bird Sounds of Eastern North America is an extremely helpful reference book for identifying groups such as shorebirds that are not directly covered by most nocturnal flight call resources.
Do I need an audio recorder or can I record directly to my computer?
You can record directly to your computer. If the audio is not loud enough you may need to boost the signal with a pre-amp.
How do you live stream your nocturnal flight calls to YouTube?
I have experimented with this using the free software OBS (Open Broadcaster Software). While using the PCM-M10 to record, I run an audio cable from the headphone jack to the line-in jack of my computer. I use RavenLite to display the spectrogram of the incoming signal. OBS takes the image from the RavenLite software and the audio from the audio-in jack and can live stream to YouTube or other sites.
Have you tried using software that automatically detects calls?
No, but I am open to the idea. I recommend that beginners spend at least some time working through long files to get an overall understanding of what sounds occur at night to better be able to tell what sounds are actually birds.
What do you hear at night besides birds?
Car horns, coughing, footsteps, airplanes, train horns, yelling, police sirens, wind chimes, fireworks, cats fighting, chipmunks running on my roof, insects, and various unexplained noises.
