'Operation Osprey' under way in Wales
12 May 2014 Last updated at 07:35 BST
Ospreys are among the rarest birds in Britain. One pair has been migrating from Africa to the same nest in Wales every Spring.
They returned once more this March to lay their eggs.
To help protect them, a team of volunteers are keeping a 24 hour watch on the nest.
Tim Muffett reports.