The successful reintroduction of extinct or endangered flora and fauna feature on a new set of stamps.

The Eurasian beaver and pool frog are illustrated on the six stamps going on sale at post offices from April 17.

Extinct or endangered species stamps
A Eurasian beaver features on one of the stamps (Royal Mail Group/Tanya Achilleo)

The sand lizard, large blue butterfly, osprey and stinking hawk’s-beard plant complete the set, illustrated by Wiltshire-based artist Tanya Achilleos Lock.

Royal Mail spokesman Philip Parker said: “When a plant or animal become extinct in a country, that does not have to be the end of the story.

Extinct or endangered species stamps
One stamp is illustrated with an osprey (Royal Mail Group/Tanya Achilleos)

“Our beautiful new stamps mark the skill and expertise of conservationists in reintroducing species back to their former environments.”