written and produced by Graham Chedd ; directed by Larry Engel ; a co-production of Chedd-Angier-Lewis Productions and Thirteen in association with WNET.ORG
by David Attenborough ; a BBC TV production in association with Australian Broadcasting Corporation, Turner Broadcasting System Inc. ; BBC Bristol ; executive producer, Peter Jones
presented by Thirteen for WNET.ORG ; Distributed by American Public Television ; A ParnassusWorks Film ; produced and directed by Richard Rifkind, Carole Rifkind
written, produced and directed by John Rubin ; a production of NOVA and National Geographic Television in association with John Rubin Productions, Inc. ; WGBH Boston