Computer Analysis of Crane Calls:
A tool for long-term monitoring, for vocal communication research
and application in endangered species reintroduction

Bernhard Weßling

Abstract.  Dr. Bernhard Wessling, a chemist and entrepreneur from Bargteheide near Hamburg, Germany has developed a computer analysis for crane calls. The calls are recorded in digital form using a powerful long-range microphone (supported by lightweight electrical infrastructure in a back-back) and analysed to deliver a sonogram and an „acoustic fingerprint“. The latter one is a spectrum showing the intensity plotted over frequency and is (as Wessling found out) characteristic for a single bird and for a pair exhibiting the unison call. This allows a long-term monitoring of individuals and pairs, because the spectrum is relatively stable over the years. 

A detailed description can be found in his internet server "craneworld", where you use „sonography“ in the navigation. This article is his presentation given on the last European Crane Workshop in Verdun, November 2000. Sound examples can be found in „View & Listen“ or under „News“. 7 different crane species have been recorded and analysed up to now.

Actually, monitoring projects are carried out by Wessling and local crane experts in Germany (3 different projects with Grus grus, one in a region with 10 pairs, another with around 100 and third with around 15 pairs), Japan (more than 20 pairs of Grus japonensis), Canada and USA /Texas (around 50 breeding pairs of the last wild and self-reproducing population of the Whooping crane Grus americana in the breeding grounds and the wintering area, resp., for and in co-operation with the Whooping Crane Recovery Team). Life history facts have been gathered from many pairs (more details in the server).

He is performing vocal communication research with the red-crowned crane in Japan and Korea / China, with the sandhill crane grus canadiensis and with the Whooping crane. This is being applied in the biggest challenge the crane world is actually faced with - the recovery and reintroduction of the endangered Whooping Crane.

A new population of captive reared birds will be released into the wild in Wisconsin, and will learn to migrate to Florida in autumn with the help of ultraleight airplanes. During raising, training and migration, the humans are vocally communicating with the birds using different vocal expressions used by wild cranes, recorded by Bernhard Wessling and played to the birds using hardware supplied by him. For more details, see his server under „News“ / November 11, August and April 2000.