- Alun Armstrong
- Â Narrator 6 episodes, 2001
- Robert Paddle
- Â Self - Psychologist 1 episode, 2001
- Beth Shapiro
- Â Self - Oxford University 1 episode, 2001
- Peter Daszak
- Â Self - Consortium for Conservation Medicine 1 episode, 2001
- Errol Fuller
- Â Self - Author 'The Great Auk' 1 episode, 2001
- Eileen Johnson
- Â Self - Texas Tech University 1 episode, 2001
- Julian Hume
- Â Self - Paleontologist 1 episode, 2001
- Tom Hayden
- Â Self - University College Dublin 1 episode, 2001
- Don Croll
- Â Self - Marine Biologist 1 episode, 2001
- Jeremy Gaskell
- Â Self - Author 'Who Killed the Great Auk' 1 episode, 2001
- Bill Montevecchi
- Â Self - Seabird Ecologist 1 episode, 2001
- Andrew Kitchener
- Â Self - National Museums of Scotland 1 episode, 2001
- Virginia Naples
- Â Self - Paleontologist 1 episode, 2001
- Menna Jones
- Â Self - Zoologist 1 episode, 2001
- Larry Toler
- Â Self - Bison Farmer 1 episode, 2001
- Blair Van Valkenburgh
- Â Self - UCLA 1 episode, 2001
- Silvia Gonzales
- Â Self - Liverpool John Moores University 1 episode, 2001
- Pete Coxon
- Â Self - Trinity College Dublin 1 episode, 2001
- Greg McDonald
- Â Self - US National Park Service 1 episode, 2001
- Christopher Shaw
- Â Self - La Brea Tar Pits Manager 1 episode, 2001
- Nick Mooney
- Â Self - Tasmanian Wildlife Manager 1 episode, 2001
- Julio Betancourt
- Â Self - US Geological Survey 1 episode, 2001
- Pieter Floore
- Â Self - Archaeologist 1 episode, 2001
- Adrian Lister
- Â Self - University College London 1 episode, 2001