Argos Newsletter N° 53 - August 1998

Akio Kunii

NTT World Bird Count Office
E-mail: wbc@wnn.or.jp
http://www.wnn.or.jp/wnn-n/w-bird/

The Migration Route Satellite-tracked by ArgoSat NTT

Figure 1: 15-gram Argos transmitter, used for tracking Far Eastern Curlews.

Argosat micro-miniature transmitters, developed by NTT, were attached to Far Eastern Curlews in Australia in March 1997. Our hope was that the 15-gram transmitter, the world's smallest, would shed light on the migratory routes of this declining species.

NTT has supported wild bird tracking projects for over 10 years by developing and repeatedly miniaturizing tiny transmitters to mount on birds. On the request of BirdLife International, an umbrella organization for the world's protection agencies, we took up the new challenge of further miniaturizing the transmitter: from 25 grams to 15 grams. A readily-available 15 gram transmitter is a breakthrough for wild bird conservation: only with such lightweight devices is it possible to survey the migratory routes of medium-sized or small birds like Waders and Sand-pipers.

After studying the three main parts of the transmitter separately, i.e. body, casing, and attachment, we managed to reduce the weight of the heaviest parts of the body - the circuit and battery - first. Then, we created a new material for the casing. Through a series of attachment tests using birds in zoos, we finally produced a new transmitter weighing less than 15 grams.

With the Argosat transmitter mounted, some Eastern Curlews stayed in their wintering grounds in Australia, while others flew to their breeding grounds.

		NTT displays easy-to-follow bird tracks at one of its wnn (World Nature Network) websites, called The Migration Route Satellite-tracked by Argosat (http://www.wnn.or.jp/wnn-n/migrant/english/index.html).

By July 1997 there had been 100,000 page hits from bird experts, students and other Internet users from around the world. We also expect the page to help raise public interest in nature and wildlife conservation.

NTT is continuously using the Argosat transmitter to help plot the migratory routes of other birds. Species tracked will include the critically endangered Black-faced Spoonbill, from spring 1998. The tracks will be presented on the website as the data arrives; so too will the continuing voyages of Far Eastern Curlews.

Figure 2: The Wild Bird Society of Japan and Yamashina Ornithological Research Institute are also tracking Black-faced Spoonbills.
Dotted lines show predicted migration paths.