
The Steller’s sea eagle (Haliaeetus pelagicus) is a
relative of the bald eagle and breeds only on the eastern coast of Russia.
It is one of the largest eagle species in the world, weighing between 14 -
19 pounds. Adults are characterized by a
large yellow beak,
and
distinctive black and white
plumage. Juveniles have a
dark beak and brown mottled plumage.
STUDIES IN RUSSIA
Starting in 1993 the Institute became involved in conservation issues with Steller’s
sea eagles in Russia. IWS staff and Dr.
Michael McGrady traveled to
city of Magadan on the eastern coast of Russia. There we
met with our Russian colleagues from the
Magadan State Reserve and went by
boat to survey small islands and coastal areas in the Tauy Bay and on the
Koni Peninsula for sea eagles. When nest sites were located we attempted to
climb the trees or
cliff nest sites to collect biological data on the
eaglets. On the Kava and Chelomzhe Rivers east of Magadan we used
ultralight aircraft
to
survey the rivers for nesting eagles. It was an excellent (and
exciting!) method of both locating nests and determining the number of
eaglets present in each nest. Of 28 territories visited, 18 were active and
produced 1.16 chicks/nest. Subsequent efforts from 1993 through 1998
provided for coverage of 1,852 km of coastline and 1,154 km of rivers where
a total of 274 nests were identified.
In 2000, another trip to Russia was funded by
The Trust for Mutual Understanding to place
backpack-mounted telemetry transmitters on nestling Steller’s sea eagles to document their movements. It was also hoped that
these transmitters would help in detecting the birds if they migrated to
Hokkaido, Japan to spend the winter. The telemetry transmitters, donated by
Communications Specialists, Inc., were designed to function for
approximately four years thus allowing long-term follow-up of the birds.
Three of the young eagles were detected in Hokkaido, Japan during the winter
of 2000/2001, two of which were later found dead of lead poisoning (see
Japan project summary for details). In August 2002 another trip was made to
Russia by our colleagues in Japan to place additional transmitters on
nestling eagles to provide a greater understanding of long ranges movements
by yearling Steller’s sea eagles. Furthermore, we are seeking to better
understand how these young sea eagles might be threatened by the lead
poisoning problems discovered in Japan.
STUDIES IN JAPAN
In 1993 IWS staff were invited to Japan to participate in discussion on the
biology of Steller’s sea eagles and to help comment in public forums on the
increased incidence of lead poisoning in winter Steller’s sea eagles.
Dr. Keisuke Saito,
wildlife veterinarian at the Kushiro Wildlife Center in
Hokkaido, Japan presented us with data on the number of Steller’s and
white-tailed sea eagles that had been
recovered dead or
dying from lead poisoning. Between 1994 and 2000, Dr. Saito and his colleagues have
encountered 72 of these eagles that have been confirmed to have been
poisoned by lead.
Lead poisoning in bald eagles in North America has most commonly been
associated with their consuming waterfowl that had lead in the bodies from
being shot with lead shotgun pellets. In Japan, the problem arose from eagles
feeding on hunter-killed
Sika deer. Because the historic food source of the
wintering eagles, northern pollock, had sharply declined, the eagles began
searching for
alternative food sources. In Japan, the regulations do not
require that hunters bring the carcasses of the animals shot out of the
field. Instead, the sportsmen remove the desired meat from the carcass and
leave the remains. While in some respects this would be a windfall for the
scavenging eagles, the remaining meat on the carcasses can contain
fragments of the lead bullets used to kill the animal. Thus, some of these
eagles later succumb to lead poisoning.
Due in part by lectures and press conferences that IWS staff participated in,
the Japanese legislature passed a law that required hunters to use
lead-free rifle bullets starting in 2000. We and our colleagues in Japan, Russia,
Europe and the United States that are working on Steller’s sea eagle
conservation issues applauded the Japanese legislature for taking this
progressive step to help conserve these eagle species. However, the law did
not apply to the use of lead slugs in shotguns and we were still concerned
with the potential for eagles to be poisoned.
In the winter of 2000, three of the young eagles equipped with telemetry
transmitters in Russia were located in Hokkaido. Unfortunately, two of the
three birds were found dead from lead poisoning. When the news of these
deaths reached the mass media in Japan, the Japanese government decided to
ban the use of lead slugs in shotguns as well as the previously banned lead
rifle bullets. Our contribution to tracking the movements and survival of
the young Steller’s sea eagles lead directly to this significant change in
Japanese law.
We are continuing to cooperate with Steller’s sea eagle conservation issues
in Japan and are planning to assist in the capture of wintering birds to
obtain a blood samples to assess the amount of lead and other contaminants
in their bodies.