POLK CITY, Fla. — The Ringling Bros. and Barnum & Bailey Circus will phase out the show’s iconic elephants from its performances by 2018, telling The Associated Press exclusively that growing public concern about how the animals are treated led to the decision.

Executives from Feld Entertainment, Ringling’s parent company, said the decision to end the circus’s century-old tradition of showcasing elephants was difficult and debated at length. Elephants have often been featured on Ringling’s posters over the decades. The decision is being announced Thursday.

“There’s been somewhat of a mood shift among our consumers,” said Alana Feld, the company’s executive vice president. “A lot of people aren’t comfortable with us touring with our elephants.”

Within two hours of the announcement, animal rights groups took credit for the decision, saying that the pressure put on the circus ultimately led to Feld’s decision.

“For 35 years PETA has protested Ringling Bros.’ cruelty to elephants,” Ingrid E. Newkirk, president of People for the Ethical Treatment of Animals, wrote in a statement. “We know extreme abuse to these majestic animals occurs every single day, so if Ringling is really telling the truth about ending this horror, it will be a day to pop the champagne corks, and rejoice. … If the decision is serious, then the circus needs to do it NOW.”

Feld owns 43 elephants, and 29 of the giant animals live at the company’s 200-acre Center for Elephant Conservation in central Florida. Thirteen animals will continue to tour with the circus before retiring to the center by 2018. One elephant is on a breeding loan to the Fort Worth Zoo.

Another reason for the decision, company President Kenneth Feld said, was that certain cities and counties have passed “anti-circus” and “anti-elephant” ordinances. The company’s three shows visit 115 cities throughout the year, and Feld said it’s expensive to fight legislation in each jurisdiction. It’s also difficult to plan tours amid constantly changing regulations, he said.