― Today Birds, Tomorrow Man ―
The little tern being a migratory bird, requires not only a welcoming breeding
area but a habitable wintering and stopover area as well. Little terns
require all of these areas in order to successfully migrate. Conservation
and maintenance of nesting sites have been supported by NPO groups and
volunteers throughout Japan. Banding surveys show little terns migrate
to Australia for their wintering site, we also carry out conservation measures
for the Australian breeding population as well. However, where exactly
the stopover sites are located is uncertain, this is not yet a target for
conservation of the species. Stopover sites are very important to a species
that travel thousands of kilometers because they provide an area for little
terns to conserve energy. Until now we were not able to research and discover
these areas due to the little tern’s size. GPS devices are too heavy to
use on small species but thanks to an ever evolving technology we now have
the ability. Accomplished by the Geolocator.
Geolocators are data loggers capable of receiving all sorts of information. For
the little tern, we chose a device to log light intensity and time. Daily
sunrise and sunset based on light intensity and time is how we receive
the latitude and longitudinal coordinates.
The geolocator was decided based on the size and ecology of the little
tern. The device and the recognizable flag must weigh no more than 1.2g
in order to be mounted to the little tern. In 2013 we attached geolocators
to 100 individuals throughout Osaka, Chiba, Tokyo, Shizuoka and Ibaraki.
By use of geolocators we determined that little terns were not heading
south by way of the shortest distance. Instead they make round trip migratory
routes along island chains and other possible areas where they might rest.
However, data from the geolocator surfaced an area surrounding the wintering
site which was unclear. The geolocator data showed wintering sites were
not in south-eastern Australia as we believed but in the north-east of
Australia as well as the Philippines and Papua New Guinea. Due to low amounts
of data we cannot yet draw any conclusions but we do know where some individuals
are wintering. To increase our data, we must find the individuals with
geolocators attached out of the entire flock and recover the devices. If you see a little tern wearing a geolocator please contact us. We look forward to your information.
Geolocator with a white flag Geolocator with a blue flag
Contact: Japanese Society for Preservation of Birds
Tel: 03-5378-5691 E-mail: fujii☆jspb.org（please change ☆ to ＠） To Fujii
Individuals attached with a geolocator
3F, 3-54-5, Wada, Suginami-ku, Tokyo #166-0012,