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The Ministry of Environment has declared the little tern as a Class II
Endangered species on the Japanese Red Data list and considers the little
tern a rare protected species by the International Endangered Species of
Wild Fauna and Flora regulation. In order to help conserve the species
we must not only protect their breeding areas, wintering areas but their
stopover sites as well. According to research data, little terns breeding
in Japan are thought to be wintering in the south-eastern Australia but
due to lack of field research their stopover sites are not known. The lack
of data is because the little tern is too small to attach heavy equipment
such as GPS, until now. In 2013, we attached units called geolocators to
little terns in Ibaraki, Chiba, Tokyo, Shizuoka and Osaka, a total sum
of 100 units. A geolocator is a device which records light intensity and
time allowing us to track the migration route. The unit plus the ID flag
weighing in at just 1.2 grams, makes it safe to use on such a small species. And,
in 2014, of the 100 geolocators deployed we were successful in retrieving
8 units. Of the 8 units retrieved data from 4 were recovered and analyzed. Although
we must continue to investigate our data and increase its reliability,
we managed to successfully collect and read information vital to our research.
According to our data one
migration route traveled directly from Japan to Australia and another route
which showed little terns to be utilizing the island chains in the Philippines
and Indonesia to head south and using the islands again on their way back.
South-eastern Australia has long been thought as the preferred wintering
site for the little tern but based
on data retrieved by the 4 geolocators, little terns may be wintering
in the Philippines and Papua New
The large amount of data surrounding south-eastern Australia may be due
to the large
number of researchers and not because of a flourishing little tern population.
We have only collected data
from 4 individuals, but wintering sites differ from one bird to the other.
A new theory suggests that
there might be an individual which crosses from Japan to Asia and then heads
south to the wintering site. Since geolocators
are said to have an error margin of 200-300 meters the data retrieved must be
investigated further before considered 100% accurate.
In the future, we must retrieve more data in order to accurately investigate
their wintering sites and stopover sites and to aid in conservation of
the little tern
This Project is funded by The Mitsui & Co. Environment Fund.