“Luckily,” said Jim Fowler, the longtime co-host of “Mutual of Omaha’s Wild Kingdom,” “I knew what to do.” As the indigenous tribe gathered around him fled the scene, Mr. Fowler remained calm, waiting for the anaconda to tire itself out before he wriggled out of its grasp and returned to work, preparing for another episode of “Wild Kingdom.”

For more than two decades, Mr. Fowler brought the wonders of the natural world to millions of couch-bound Americans, mixing entertainment and ad­ven­ture with storytelling that raised awareness of the planet’s biological diversity and environmental woes. He was 89 and had a heart ailment when he died May 8 at his home in Rowayton, Conn., said his son, Mark Fowler.

Mr. Fowler traveled to all seven continents for “Wild Kingdom,” wrangling animals including tigers, alligators and anacondas. (Mutual of Omaha’s Wild Kingdom)

Standing 6-foot-6 and weighing more than 200 pounds, the elder Fowler was known for swimming through snake-infested waters, diving with sharks and rappelling down remote cliff faces while his partner, zoologist Marlin Perkins, often watched from the jeep or narrated from the studio — much to the delight of “Tonight Show” host Johnny Carson.

“Johnny would imitate Marlin, saying, ‘I’ll stay back at camp mixing drinks for the native girls while I send Jim downriver to wrestle the two-horned rhino in heat,’ ” Mr. Fowler once recalled. In fact, both men played a crucial role in popularizing wildlife series and nature documentaries.

Lugging heavy cameras and tripods to all seven continents, they introduced baby boomers and their parents to unusual creatures as well as indigenous groups such as the San, or Bushmen, of the Kalahari Desert. Their show spawned legions of imitators, including shows on the Discovery Channel and Animal Planet by Steve Irwin — whom Mr. Fowler said he admired, even as he lamented Irwin’s choice of short pants over long khakis.

Mr. Fowler and Peter Gros in 2002. (Nati Harnik/AP)

Premiering on NBC in 1963, “Wild Kingdom” ran in syndication beginning in 1971 and was broadcast to more than 220 stations, reaching an estimated 30 million weekly viewers and winning four Emmy Awards. The series was initially helmed by Perkins, a white-haired former director of the Lincoln Park Zoo in Chicago.

Mr. Fowler served as co-host and sidekick (he was joined for several years by Stan Brock), then took over after Perkins retired in 1985, leading the program until production wrapped the next year. The series was revived by Animal Planet in 2002.

He also hosted a successor program, “Mutual of Omaha’s Spirit of Adventure,” served as the wildlife correspondent for NBC’s “Today” show and was a frequent guest of television hosts such as Carson, often appearing onstage alongside an overfriendly boa constrictor or sunflower-seed-eating squirrel monkey.

For “Wild Kingdom,” Mr. Fowler braved wind chills of 76 below while tracking polar bears in Alaska, perched on a helicopter pontoon to tag a moose by the ear, lassoed an alligator and used a “catcher stick” to rescue a puma from floodwaters.

An authority on birds of prey, he established his bona fides as an adventurous wildlife filmmaker when he flew to British Guiana in 1955 to study the harpy eagle, one of the world’s largest raptors. Accompanied by ornithologist Jim Cope, he spent weeks exploring the northern Amazon, using ropes and climbing spikes to ascend to the rain-forest canopy and study the birds in their natural habitat.

He returned to the United States with 16-millimeter film footage, material for an ornithological research paper and three harpy eagles, one of which joined him for an episode of the “Today” show. The appearance drew the attention of Perkins, who had previously hosted the Chicago program “Zoo Parade” and was looking to start a new nature series.

Mr. Fowler “was trying to create some hope and interest in the next generation about what they can do to participate in preserving the natural world,” said Peter Gros, his co-host for several years on “Wild Kingdom” and “Spirit of Adventure.”

“There are so many shows that are based on teeth and claws, and what Jim was doing was trying to replace fear with knowledge about wildlife, and with concern and appreciation,” he said in a phone interview. Still, he added, Mr. Fowler knew his way around carnivores — and was so experienced he sometimes averted potential disasters.

For one episode, Mr. Fowler and Gros visited alligator researchers in Louisiana and floated through the bayou at night in a flat-bottomed paddleboat, tagging gators for further study. With lights from the boat, “you could see a runway of red eyes,” Gros said.

“It was my turn to tag,” he recalled, “and as I reached down I felt this big hand on my shoulder. ‘Not that one,’ Jim said. ‘His eyes are too far apart — he’s eight feet long, not four feet.’ Jim knew that the length between the eyes meant the length of the alligator.”

“If it hadn’t been for Jim,” he continued, “my nickname would probably be ‘Lefty’ today.”

The fourth of five boys, James Mark Fowler was born into a Quaker family in Albany, Ga., on April 9, 1930. He spent much of his childhood at Mud Creek, the family’s 680-acre farm, which he later turned into a free-roaming wildlife preserve home to wolves, hyenas, zebras and other animals.

His mother was a homemaker and former suffragist, and his father was a federal soil scientist who worked for a time in the Washington area, leading Mr. Fowler to attend elementary school in Falls Church, Va.

Drawn to the outdoors from a young age, he collected snakes and sold them to a nearby herpetarium for $1 each. By 7 he was also immersed in falconry, training kestrels with the help of books and later a mentor, John Hamlet.

Mr. Fowler received a Quaker schooling, attending the private Westtown School in suburban Philadelphia and Earlham College in Richmond, Ind., where he studied zoology and geology while excelling in sports. He once said that after graduating from high school he turned down a $30,000 paycheck from the Philadelphia Athletics baseball team and committed to becoming a naturalist only after suffering a knee injury in a college-football game.

He graduated in 1952 and was working as an educator at Hamlet’s raptor sanctuary, near Ocala, Fla., when he met Perkins for the first time. “Marlin did a show from there,” Mr. Fowler told the Memphis Flyer newspaper, “and my boss said, ‘Marlin, have the boy go get the eagle.’ I was in my early 20s.”

In 1970 he married Betsey Burhans, a wildlife artist. In addition to his wife, survivors include two children, Mark Fowler and Carrie Fowler Stowe, who co-hosted the nature series “Life in the Wild” with their father beginning in 2000; and two grandchildren.

Mr. Fowler was honorary chairman of the Explorers Club and created several wildlife refuges, including at his former estate in New Canaan, Conn.

In interviews, he sometimes recalled that the first episode of “Wild Kingdom” nearly ended in disaster. Filmed in Chicago’s Lincoln Park, it featured one of the massive harpy eagles that Mr. Fowler had captured and trained.

He said he kept the bird on a line to prevent it from escaping and frightening Chicagoans who might mistake the bird for “a pterodactyl.” But after the crew encouraged him to let the bird fly free in an effort to improve the shot, Mr. Fowler tried an experiment, placing it in a tree but still on the line.

Unfortunately, he told the Omaha World-Herald, a woman and her poodle had made their way into the roped-off filming area. The bird took flight, apparently spotting a meal. “Thank goodness I was able to grab the line,” Mr. Fowler said. “Had the eagle grabbed the woman or the dog, my career would have been over before it started.”