The team are looking for evidence of Bengal tigers in Bhutan. These are the largest of the world's big cats and can weigh up to 300kg. Despite their size they are extremely secretive and difficult to track down in Bhutan's forest wilderness.
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Wildlife cameraman Gordon Buchanan searched for tigers in the high Himalayas following rumours from local people that tigers live in the mountains.
Gordon has filmed big cats all over the world. Trying to find tigers here proves to be his biggest challenge yet.
Browse the BBC natural history archive and find out more about tigers.Watch tigers in action
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"When I saw the first images of the tigers on the camera traps from the mountains I was completely overwhelmed. It was very emotional." Presenter and cameraman Gordon Buchanan on being part of an amazing discovery.Gordon Buchanan on his emotional Himalaya tiger hunt
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