Echo of the elephant Nature / produced by Marion Zunz ; written by David Attenborough, Cynthia Moss ; filmed and directed by Martyn Colbeck ; a co-production of Thirteen/WNET and BBC-TV. Nature. Echo of the elephants : the next generation / directed & filmed by Martyn Colbeck ; scientific consultation/writer, Cynthia Moss ; producer, John Sparks ; a co-production of Thirteen/WNET and BBC-TV.