a BBC Studios Natural History Unit production ; a co-production with BBC America, Tencent, WDR, France Televisions and CCTV9 ; a BBC Open University partnership ; executive producer, James Honeyborne ; series producer, Mark Brownlow ; producers, Miles Barton, Orla Doherty, Kathryn Jeffs, Will Ridgeon, John Ruthven, Jonathan Smith
written, produced and directed by William Cran ; a Frontline coproduction with InVision Productions, Ltd. in association with BBC-2 ; WGBH Educational Foundation
A production of The Documentary Guild in association with WGBH Boston for Nova ; WGBH Educational Foundation ; Executive editor, William Grant ; executive producer, Paula S. Apsell ; written, produced and directed by Rob Whittlesey and Noel Buckner
produced by Randall MacLowry, Tracy Heather Strain ; written and directed by Tracy Heather Strain ; senior series producer, Susan Bellows ; a Film Posse, Inc. production for American Experience