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
written, produced and directed by Linda Garmon ; a Nova production by the WGBH/Boston Science Unit in association with BBC-TV, NDR International Hamburg and Nederlandse Omroepprogramma Stichting
presented by Thirteen for WNET.ORG ; Distributed by American Public Television ; A ParnassusWorks Film ; produced and directed by Richard Rifkind, Carole Rifkind