© 2019 -  Joost Van Duppen

SOUND CONSERVATION - SKAGEN

Skagen Bird Observatory

During the spring and fall, millions of birds fly enormous distances to their summer or winter residence. Skagen is a popular resting area where these birds feed to continue their long journey. That makes Skagen an interesting place to monitor these routes. By varoius techniques in research we can improve the route mapping. The Skagen bird observatory gives room for experimentation into new monitoring techniques.
This supports research into navigation, population and behavioral changes and the spread of diseases of migratory birds.

© SBO - Sunset Skagen Light house

Observation

Observing is the most popular and accessible method. With the help of binoculars you can easily hoover the area for birds flying over or foraging.  A telescope gives you a close up for determination. For example, even the ring number can be read with seagulls. The flight direction and behavior can be studied.

© SBO - On the way to our observation posts

Ringing

Ringing birds is a carefully task. It is regulated and vary from country to country.
For Denmark you need a certificate to participate in the ring activity.  After a positive evaluation of the internships and exams you can ring birds independently.


Placing nets:
The previous days nets are placed at strategic places. Often between low forestation, shrubs, marshes and wind-free, so that the birds do not fly into the net in full flight and avoid injuries. The nets must be prevented from hanging on the ground, closed off from the ring activity and free from branches.

Starting ring activity:

The nets must be opened half an hour before sunrise. Every half hour the birds are taken out of the nets to ring them, until the afternoon.When ringing, first place the ring and note the ring number, wing length, gender, age, molding, fat score and weight. After that the birds are let go again as quickly as possible.

© SBO -In the field, we use mistnets to catch the birds when they jump with low flight speed in between the reeds or bushes, to prevent injuries.

After the ring activity:
All nets are closed and locked to prevent other birds getting caught in them.
The data is entered in the database.


When catching the birds we can closely observe the condition of the bird, such as health, anatomy, age and sex. Because this is a very representative method, it is widely used.

© SBO - Tchiff tchaff and the Willow Warbler are very common birds, looks and sound the similar.

Nocturnal Bird Migration

In addition to the ring activity, I had the opportunity to record nocturnal migration based on sound tracking in parallel with active recordings that were recorded for the study of soundscape ecology, which indicates the biodiversity of the area.

The recordings are made from sunset to sunrise and are analyzed by spectrograms that show the presence of different species. These spectrograms on sonograms are a visualization of sound frequencies over time. You can see the birdcalls that make it possible to analyze many recordings without listening to the entire file.
The data is recorded in a map system to support the preparation of the migration map of Europe.

© SBO - Spectrogram or sonogram that visualizes the bird sounds: X axis shows the time and the Y axis presents the frequency. Most of the birds are located between 2kHz and 8kHz, higher up you can see some overtones that helps to identify species as well.

Future perspectives

The collected data or sound records are processed by hovering through the spectrogram, listening and identify by ear for one single audiomoth running. 

A possibility is to expand the amount of audiomoths in square gradients of 500 meters and collect the sound data for a certain area during the migration period for several weeks.  The data processing will be very work intensive and than it is better to process the records through machine learning: the computer will be trained by analysing samples from local birds and can match them with the new recorded material.  

Another method is to expand the machine learning by a citizen science platform.

© SBO - Workshop & data input

© SBO - The Audiomoth is a mini computer that has a microphone on the right side down.  It can be programmed to record certain periods of interests over several weeks.

© SBO - Parabole to concentrate the migrator sounds and reduce the ambient noise

Radar

The maritime radar can observe large numbers of birds in a flocks at great distances, which we can monitor and identify with the telescope a little later. The flight direction, behavior and number are recorded. Observations with the radar are possible at low wind speeds and dry weather, mainly just before and after sunrise and sunset.

© SBO - Radar Detection of Birds

Radiotelemetry

A project from the University of Copenhagen running at the Skagen Fuglestation, where birds are tracked by geolocation.

The antenna is connected to a raspberry pi .  It collects the data from the movement of birds that are marked by trackers.  With this information we can determine bird movements over areas ranging in size from the restricted territories of resident bird species to the movement patterns of international migratory species.

© SBO - Antenna

© SBO - Nature Reserve Skagen

 

Field Recording Canoe Trip

In July we've organized a field recording trip on the Saimaa Lake from Oravi to Kolovesi National Park. The silence was overwhelming and the recording of pure sounds of certain species are an enrichment for the expansion of the sound library. Because we had to move by water, the equipment remained limited, but that did not prevent the recording of beautiful sounds. We would like to share this experience and organize in the near future with various artists.

© Saimaa 2019 - Biwak place

© Saimaa 2019 - Early Morning Record Session

© Saimaa 2019 - Sunrise durign Early Morning Record Session

 

Field Recording Trip Finland June 2018

At the end of May 2018 I organized a field recording trip in North-East Finland. We explored the North-East Finnish nature. By the start of the early summer in Finland, quite a few birds were already breeding, but at least we were able to make proper recordings overnight in different places with binaurals and ambeo microphones. It was an expedition where we discovered beautiful shooting locations.
 

© Pallas National Park - June 2018

© Kilpisjärvi June 2018

© Martin Selkonen - North East Finland - June 2018

IN PROGRESS