“He’d just flown for five hours after injuring himself in a motorbike accident in the forest in Zaire,” the filmmaker Mark Deeble, a friend for whom Mr. Root was a mentor, said of one such reunion, “and his lip was in tatters after a ‘tame’ marsh mongoose had fastened on and decided it was edible.”
Mr. Root was born on May 12, 1937, in London, where his father managed a fish-paste factory until after World War II, when a new job took him and the family to Kenya. While still a boy, Mr. Root started filming animals, mostly snakes, using an eight-millimeter camera.
His earliest professional jobs included working on the 1959 documentary “Serengeti Shall Not Die,” which was being made by the father-son team of Bernhard and Michael Grzimek. When Michael Grzimek was killed in a plane crash before the film was finished, Mr. Root took it upon himself to complete the movie, which went on to win an Oscar.
In 1961 he married Joan Thorpe, the daughter of a British coffee farmer in Nairobi, and the two collaborated on documentaries that helped bring the natural world to television viewers in England and the United States in vivid fashion.
“Baobab: Portrait of a Tree” (1973) examined the birds, insects and other animals that live in a particular type of tree found in Africa. “The Year of the Wildebeest” (1975) tracked the migration of the great herds in the central African plains. “Mysterious Castles of Clay” (1978) was about giant termite mounds.
The Roots are said to have shown the American zoologist Dian Fossey, of “Gorillas in the Mist” fame, her first mountain gorillas. Years later Mr. Root filmed a sequence for that 1988 movie, in which Sigourney Weaver played Fossey.
The Roots turned their home on Lake Naivasha in Kenya into a sort of sanctuary, harboring all sorts of animals. The writer George Plimpton was a frequent visitor.
“On one occasion,” he wrote in a 1999 article for The New Yorker titled “The Man Who Was Eaten Alive,” a reference to Mr. Root’s run-ins with wildlife, “what I thought was a water bed on the far side of the living room got up, walked out the door, across the grass, and into the lake — a pet hippo named Sally.”
Joan Root stayed at Naivasha after the couple divorced in 1990 and became an advocate of conservation practices on the lake, battling illegal fishing. In 2006 she was murdered by gunmen on her property.
Mr. Root married Jennie Hammond in 1991; she died in 2000. He is survived by his wife, Fran Michelmore, and their sons, Myles and Rory.
Mr. Root told his story in an autobiography, “Ivory, Apes and Peacocks: Animals, Adventure and Discovery in the Wild Places of Africa,” published in 2012. At his death he was an executive producer of a film that Mr. Deeble and his wife, Victoria Stone, are making about an elephant family.
Wildlife filmmakers praised Mr. Root for having the patience necessary to achieve striking shots.
“If he wanted his audience to experience the termites’ point of view of what it was like for the colony to be raided by an aardvark, that meant Joan putting years into raising an orphaned aardvark to accomplish it,” Mr. Deeble wrote in a blog entry on the occasion of Mr. Root’s death.
Mr. Root was also admired for telling the story of an entire ecosystem, not simply serving up a bunch of pretty scenes. And he helped lead wildlife filmmaking away from a reliance on human interaction, letting the animals be the stars.
For Mr. Root, the adventurous spirit that made him a great wildlife filmmaker came with a certain nonchalance. Mark Seal, who wrote a Vanity Fair article and then a book (“Wildflower: An Extraordinary Life and Untimely Death in Africa”) about Joan Root’s murder, recalled arranging to talk with Mr. Root, whom he had met only briefly, at a friend’s home.
“I expected Alan to come walking through his friend’s house,” Mr. Seal wrote in an email. “Instead, I heard a roar, and he descended into the yard in his helicopter, picked me up and flew me over the wildlife-infested plains of his beloved Kenya. ‘I’ve crashed two of these,’ he advised me midflight.”
Mr. Seal added, “Will never forget him holding the copter throttle with that hand missing the finger that the puff adder had taken.”