Successful project to remove invasive rodents from the Calf of Man

Initiative involved 13-year project between MNH and Manx Wildlife Trust

A long running project to remove invasive rodents from the Calf of Man has enabled Manx Shearwaters - once declared extinct on the Island - to return.

The initiative has involved a 13-year collaboration between Manx National Heritage and the Manx Wildlife Trust.

It's transformed the ecological outlook for the nature reserve enabling the return of key seabird populations - particularly ground-nesting species vulnerable to predation from brown rats.

The Calf now has up to 1,500 pairs of breeding Manx Shearwaters. There's also around 100 pairs of Eider ducks - another species that had disappeared from the Island.

In the last two years the formerly extinct Water Rail have re-established a local breeding population of two pairs on the Calf, and 2025 saw the highest number of Puffins arriving in over three decades.

The landmark programme to remove invasive rodents has earned MNH and MWT the award for Environmental or Sustainable Initiative of the Year at the Media Isle Man awards for Excellence.