5/5 Mary meets grey seal expert Sue Sayer in Cornwall to observe the animals.
4/5 Mary Colwell meets a man whose life revolves around tiny green plants.
3/5 Mary Colwell meets a man who has spent his life searching for corals on the Devon coast.
2/5 Mary Colwell meets a water vole warrior determined to save them from disappearing.
1/5 Mary Colwell meets a doctor who has a passion for creepy crawlies.
3/3 Paul Evans meets Roy Dennis, who has spent a life with ospreys, in the Scottish Highlands.
2/3 Paul Evans goes to Maine to meet a conservation biologist who has spent a life with loons.
1/3 Writer and naturalist Paul Evans meets Prof Lynn Margulis.
3/3 Grant Sonnex talks to Pete Abraham, a Yupik Eskimo who grew up in a tiny settlement.
2/3 A couple who study the spawning grounds of the world's last great salmon run.