Night migration : Shorebirds at the window !

Night migration : Shorebirds at the window !

Who hasn’t seen this animation from the Cornell Lab of Ornithology showing birds taking off a few minutes after the sunset ?


Not only birds do migrate at night, but this migration can be MASSIVE.

Moreover, most of the species that migrate at night can rarely be seen migrating in daylight : Shorebirds, Rails, Warblers…Which means that we’re just missing thousands of birds that are flying over us while we can’t see them !

Fortunately, many species are vocal enough to be be detected through their flight call. So, I wanted to have a try and get a real feeling of what night migration sounds like…

But… What if I sleep at night ?

Yeah, good point. There are two major issues with night migration

  1. If you’re a normal human being, you don’t go birding at 3 a.m
  2. Since you can only detect birds that are calling, listening at night can be very boring , with hours without any sign of a bird

Don’t worry, here comes technology ! The idea for night migration is that the microphone will work for you. You just put a microphone anywhere in a safe, quiet place, and then you can have a 7-hour recording of all that flies over during the night.


OK but wait… when do I listen to a 7-hour long recording ?

Sonograms bro.

You obviously don’t have time to listen to a full 7-hour track. So, the idea is exactly the same as when you’re on a diurnal migration spot. You don’t stay several hours with your scope stuck in a single direction, but you look at the landscape with the naked eye , and then focus on anything that stands out against the sky and looks like a bird.

This is exactly what a sonogram does. It’s a visual picture of a soundscape. Just draw the sonogram and you can see a 1 min long recording at a single glance. Hence, by scrolling the sonogram, you can “see” the whole 7 hour recording in a limited time.


Just as you can spot this Lammergeier (Gypaetus barbatus) at a glance in the middle of the landscape, you can spot birds at a glance on sonograms ©Stanislas Wroza


You can clearly spot the calls of a migrating Wood sandpiper (Tringa glareola) without listening to the whole 1 min long recording.


How do I make a sonogram ?

I’ve already explained this here :

 Softwares and audio processing

It takes some practice to be able to tell the difference between a bird call and some other noise on the sonogram .The first times it will take more time to scroll the full recording looking for bird calls, but you will quickly be able to do it much faster.

Great.  Does it really work ?

I had a try.

First, I must say that I didn’t chose the best place neither the best time of year for night migration…

I started recording night migration from a little park with Holm Oaks in the center of a big town (Montpellier).  As there are roads around this area, we can’t say that it is a quiet place.

And to say the least, the end of June is not the best time for migrating birds either…


My night migration spot, not really where you would expect Shorebirds…


But I didn’t care, I just wanted to see if some birds were flying over, and if I could really hear and identify them.

First night, sleeping while the microphone was running…until 7 a.m in the morning, getting up, turning off the microphone and having my breakfast while scrolling the sonogram on my computer.

As expected, the night was very quiet, nothing for the first two hours… until something like this appeared :


Eurasian Stone-Curlew (Burhinus oedicnemus)


Is it ???… Yes it is, first bird : A European Stone Curlew (Burhinus oedicnemus) ! Flying over buildings in Montpellier ! For me, it was amazing to get this species from a small urban park.

An example of flight call of Eurasian Stone-curlew (not the one I recorded over Montpellier).

Since then I’ve been recording as often as I could/had time. We’re only in July and I’ve already had 9 species of Shorebirds and even a Little bittern. This shows that these birds can be heard in migration almost anywhere, you don’t even have to be on the coast, or close to a lake.

This definitely changes your vision of birding for Shorebirds.


To have a look at my recent sightings, just click here :



2 thoughts on “Night migration : Shorebirds at the window !

  1. Great idea and article!
    Quick question before trying it out myself : any advice on protecting the recorder against the rain without shielding off the “line of sound” from overhead flying birds? I could put it under
    an umbrella or skylight, but that would reduce the detectability of distantly calling birds I presume.

    1. Thanks for this comment Dries.
      I usually don’t take my microphone out when rain is forecast. Yet, the best thing I’ve found so far against occasional rain and wind is to use cut tights (=pantyhose) as a protection. I use the fabric in which the tights are made as a cover that I put about 20 cm above the microphone.If there’s a small slope, the raindrops should drip away from the place where the microphone is.
      This “tights roof” + the windjammer on the microphone is enough to protect your recorder from raindrops (maybe not from a storm !) and is almost 100% transparent from sound.
      You can also use plastic wrapping to protect the parts of your recorder where there’s no microphone. But don’t put plastic film on the microphone as it’s not “sound transparent”

      I’m not sure if I’ve been clear enough. Don’t hesitate to ask for clarification if needed.

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