Where and when to record birds ?

Where and when to record birds ?

Now that you know everything about sounds and got your recording device whith the right settings, it’s time to go out on the field and listen for birds.

When ? Time of year and time of day :

Even if calls can be heard all year long ,the vocal activity of most species is concentrated during spring (mating time). At the daily scale, most birds concentrate their efforts at dawn, even if causality behing this phenomenon is not fully resolved.

Red-eyed vireo (Vireo olivaceus), an unstoppable singer ! ©Stanislas Wroza

Yet, some species such as Coal tit (Periparus ater) virtually sing all year long and at any time of day. Red-eyed vireos (Vireo olivaceus) hold the world record of the craziest singers : They can repeat the same phrase over 20 000 times a day !

Weather conditions :

During wet or windy days, the quality of recordings is strongly impacted. Humidity is also dangerous for your microphone since a lot of electrical components are in contact with air.  Luckily enough, those days are also bad for migration and birds are less vocal. Therefore, I recommend leaving your microphone at home on rainy days and … look for shorebirds or stuff like that since rain stops their migration !

Where and how  ?

You can record birds virtually everywhere. Most people tend to think that recordings are not worth anything if not taken in a perfectly quiet place. But the magic of bird songs unveils unexpected advantages

Indeed, bird songs are commonly produced at frequencies located between 1 and 10 kHZ, while mechanical noise (the hustle and bustle of the city’s activity) is usually lower pitched (between 0.1 and 0.5kHz). That is to say : they do not compete on a spectrogram. A high-pass filter (see Sound processing ref) can separate those sounds.

The sounds from the distant town appear on the spectrogram as a constant, noisy block below 1000 Hz, while the flight call of a Black woodpecker (Dryocopus martius) and the song of a Great tit (Parus major) are higher pitched (about 1900 Hz and 4000Hz respectively).

Thus good recording conditions are not necessarily a perfect quiet but a stable environement. The never ending noise of a city down the hill is not as inconvenient as people sporadically walking by and talking close to you in a perfectly quiet place. Planes flying at low altitude can be fairly annoying too.

For these reasons, recording on the top of a roof in the middle of a city can produce unexpectedly good, well-identifiable spectrograms. More generally speaking, elevated places are to be preferred since migrating birds will be more likely to fly closer to you and you’ll have less obstacles to obstruct the view and sound propagation.

One final thing to know is that you should avoid recording while walking, and manipulate your microphone with slow, smooth moves when changing the direction you’re pointing it at. Moving your microphone in the air is like handling it in an equivalent opposite wind, which creates low-frequencies sounds on your recordings. For these reasons, avoid unnecessary accelerations for your microphone.





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