It’s a jungle behind the scenes at New York’s venerable Explorers Club.

After astronaut Sen. John H. Glenn was announced as honorary chairman July 2, some have cried foul, alleging that predecessor James Fowler — former host of “Wild Kingdom” — was “covertly” pushed out in a move that could ultimately doom the fabled institution.

But others at the club say the grumbling is from a small number of “radical” members who “are nothing more than angry troublemakers.”

The squabbling is just the latest at the Upper East Side club: Page Six previously reported that members, including History Channel host Josh Bernstein, were in a skirmish with former president Lorie Karnath, whose reign prompted one to decry, “Sir Edmund Hillary, our late honorary president, is probably rolling over in his grave.”

This time the ruckus is over Hillary’s former post of honorary chairman, which had been filled by Fowler, known for bringing exotic animals to the club’s annual dinner. Under new president Alan H. Nichols, Fowler was eased out. Member H. Bruce Rinker then sent out a letter claiming Fowler was “covertly ousted” from his role at the 3,000-member organization (which one habitué said has factions of “sea people, polar people, conservation people and space people”).

Rinker wrote the move aimed “to remove all honest critics of the club’s present direction . . . turning it into a private preserve of mediocrity and cronyism that may lead ultimately to the demise of this august 109-year-old institution.”

Fowler was more philosophical, telling us: “I’ve been around awhile, I know the way things work,” and in a statement, “It has been an honor to follow in the footsteps of Sir Edmund Hillary . . . I have not resigned but have been asked to step down from my position. I will continue to work hard to maintain the prestige, the honor and the reputation of the Explorers Club.”

Executive director Will Roseman said: “Jim certainly wasn’t thrown out. He is a beloved member of the club, and nobody would do anything untoward. His term expired.”

Nichols downplayed any squabbling, telling us, “We have so much more going on now,” than any infighting. “We just had one of our most successful annual dinners, that sold out… that hasn’t happened in years. Any factions are really just a couple people.” He added that he’s hoping to have a dinner in Fowler’s honor, and added that “John Glenn is a huge hero.”