The sound of silence

Today was another weather-limited day, Chris braved the wind and rain for a very wet 3-hour Seawatch session, highlights were two Little Gulls (Dværgmåge) and a fulmar (Mallemuk)!

We used our time indoors to update and organize the picture archive with many detailed photos of our recent catching’s, mostly woodcocks spotlighted during the last nights and to dive into a new project that was started this autumn at Skagen Bird Observatory: night sound recording!

Don’t be alarmed by the title, while for most of us birding is a primarily a visual experience darkness doesn’t mean the end for bird activity. Not only owls and nightjars begin their activity but also diurnal birds are very active as most songbirds migrate during night time and out aim is to also “observe” them migrating over-head in total darkness.

Look at all the birds! Det Grå Fyr at night. Photo: Laia Soler

How?

The recording process is pretty straight-forward, using a specialized microphone aimed at the sky and placed at our ringing site we recorded all sounds from dusk till dawn, and after collecting it in the morning we can download all the data gathered to the station’s computer and start with the analyses process.

Prepering the sound recorder and the Microphone at Kabeltromlekrattet.

Using a software designed for wildlife recordings made by Cornell Lab of Ornithology we analyse the whole night; the program also turns the sound into a visual form called spectrogram or sonographs making the calls birds make in the darkness “visible” for us.

The visual form of a Redshank (Rødben) calls during the night in September

Our processed observations are then catalogued on our database and the totals for the night are entered on Trektellen, you can follow them here: https://www.trektellen.org/count/view/2601/20191010 as we will continue with our analysis over the next weeks.

We are hoping this new and exciting project will help us better understand what birds are doing over Grenen together with the data we already collect through ringing and observations.

Folk: Christian Stolz, Judith Kloibhofer, Laia Soler Iglesias, Yotam Lehnardt.