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Last Updated: Tuesday, 24 April 2007, 23:40 GMT 00:40 UK
Walrus sat-tags beaming up data
Greenland walrus
Scientists want to find out where these animals migrate
Six of the eight satellite tags recently attached to walruses in west Greenland are working successfully.

They have revealed that, so far, the majority of the tagged animals have remained close to the ice-covered bank where they were tagged.

Scientists are hoping the devices will help solve the mystery of where these animals migrate over the summer.

The mammals' movements can be followed on the BBC News website's walrus migration map.

Erik Born, a biologist at the Greenland Institute of Natural Resources and lead researcher on the walrus tagging project, said: "The satellite data shows that five of the tagged walruses (W1,W2,W5, W6 and W7) are still staying close to the area where they were tagged.

"There is still a lot of ice here and they will likely not start to migrate until the ice begins to disappear."

Another young male walrus (W4) has headed north to a shallow foraging bank that is close to Disco Island.

Greenland walrus

A lot of walruses used to be found in this spot, explained Dr Born, "but there have not been so many in later years".

Two of the tags have not been sending location coordinates. These had been attached to a female walrus, aged between eight and 10 years, and another walrus that was thought to be her son.

Dr Born said this occurrence was common in this area of marine mammal research, particularly with walruses.

"There are many reasons why they may not be signalling - they could have been scratched off, or the aerial may have broken off as the walruses hauled out on to the ice."

The team is also discussing the possibility whether another signal from the tag attached to W3 may have been an anomalous signal. The scientists hope to clarify this soon.

Dr Born says he believes the working tags will begin to relay where the walruses are migrating to in the next few weeks, as soon as the ice, which is especially plentiful this year, starts to disappear.

MIGRATION MAP
Walrus map
Walrus 1: Male, 4-5 years
Walrus 2: Female, 10-12 years - has yearling calf in tow
Walrus 3: Possibly anomalous data
Walrus 4: Male, 5-6 years
Walrus 5: Male, 18-20 years
Walrus 6: Female, 5-6 years
Walrus 7: Male, 5-7 years
(No data yet received from a tagged female and her son)

The tagging study is being run by the Greenland Institute of Natural Resources, in cooperation with the Danish National Environmental Research Institute and the Technical University of Denmark.


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