In early summer at the Knepp Rewilding Project in West Sussex you're almost guaranteed to hear a turtle dove, one of the UK's rarest birds. Conservationist Isabella Tree writes how its gentle soothing sound tugs at the heartstrings, as today fewer than 3000 breeding pairs remain. But at Knepp, turtle doves can find areas of dense thorny thicket where they like to nest, and wildflower seeds to eat. Now every year they count 20 singing males, which is a quater of the population in Sussex.

Produced by Sophie Anton for BBC Audio in Bristol.

This programme features audio recorded by Hazel Reeves at Knepp.