蜜芽传媒

Mark from the British Trust for Ornithology shows Chris Packham and some kids how to ring a bird. He's got a sedge warbler, which has migrated to the UK from Africa. Mark shows them how to tell the sex of the warbler - you blow on its belly to see how thick the feathers there are. This one is a male. Mark and Chris release the bird after its has been ringed.