With fewer visitors, businesses might be less interested in paying for zoo sponsorships, Bonner said. Donors, too, might flee. The zoo is known as the world’s best free zoo, Bonner said. An admission fee would chip away at the zoo’s identity.

A sales tax, said Matt Geekie, president of the Zoo Association, is the most egalitarian. A family of four with a total income of $40,000, he said, wouldn’t possibly pay more than $40 a year on a one-tenth of a cent sales tax, for instance. But if it cost $25 a head to get into the zoo, they’d pay $100 for one visit.

“Think about the unity that this zoo represents for the region,” Geekie said. “Let’s be less divisive.”

‘gradual but steady decline’

Zoo polling has shown widespread support for a sales tax, said Jeff Rainford, former chief of staff to St. Louis Mayor Francis Slay and a current consultant for the Zoo Association.

As an average, 66 percent of the polled residents in all five counties supported a zoo sales tax, while just 28 percent didn’t, he said. In the city, the number grew to 70 percent. Even in Franklin County, it was 62 percent in favor, Rainford said.