John Henry Barrett MBE (21 July 1913 – 9 February 1999) was a pioneering conservationist, author and broadcaster, who was the first Warden at Dale Fort Field Centre in Pembrokeshire.
The next years were spent in a succession of prisoner-of-war camps across Germany and Poland: Oflag VI-B (Dössel, near Warburg), Oflag XXI-B (Schubin), Stalag Luft III (Sagan) (where he was part of the support team for the "wooden horse" escape) and Stalag III-A (Luckenwalde).
It was in Oflag VI-B that he met John Buxton, Peter Conder and George Waterston.
These four recorded migration patterns and the minutiae of tree sparrow and chaffinch nesting behaviour.
He was appointed Minister's Nominee to the fledgling Pembrokeshire Coast National Park, initiated a series of guided walks, fought for the establishment of a coastal path (he wrote the HMSO guide to the path), and served on the Park Committee for twenty-five years.