ST. PETERSBURG, Fla. – Hoping to block more hunts, the environmental group Center for Biological Diversity has filed a petition with the U.S. Fish and Wildlife Service seeking to have Florida's black bears protected under the Endangered Species Act.

"Without Endangered Species Act protection, the Florida black bear could once again find itself on the precipice of extinction," said the petition, which was filed Thursday.

The petition — also backed by the Sierra Club, the Humane Society of the United States and the League of Women Voters of Florida — contends that the bears face serious challenges ranging from a shortage of palmetto berries to the loss of habitat to development.

"2015 was a deadly year for the Florida black bear," the petition said. "Collisions with vehicles killed at least 169 Florida black bears, wildlife managers killed at least 108 Florida black bears that were considered nuisances or threats to human safety, at least 9 were killed illegally, and in October hunters killed at least 304 Florida black bears in the first bear hunt in 20 years."

The state Fish and Wildlife Conservation Commission once listed Florida's bears as a threatened species but took them off the imperiled wildlife list in 2012. Four attacks on humans occurred between 2013 and 2014, prompting the commissioners to bring back bear hunting last year.

Although the hunting season was supposed to last a week, hunters killed so many bears so quickly that commission executive director Nick Wiley ended the hunt after just two days. Wiley said this week that the commission has made no decisions yet on holding a hunt this year.

The federal wildlife agency has considered listing Florida's bears on its endangered or threatened list before.

In 1992, the U.S. Fish and Wildlife Service said listing the Florida black bear was "warranted but precluded" under the Endangered Species Act, meaning that other species needed protection more urgently and the government did not have enough money to cover everything.

Six years later, though, the agency decided the bears did not need protecting after all.

"A status review estimated the sustainable population at 1,600 to 3,000 bears covering much of the species' historical range," Sam Hamilton, regional director for the Fish and Wildlife Service, said in 1998. "We have made a new finding that listing the bear as endangered or threatened is not warranted at this time."

Hamilton said the agency was confident the bear had a "stable" future thanks to the state's land management rules — rules that have since been abolished by the Legislature.