Colin Braley, File, Associated Press
FILE - In this June 11, 2009 file photo, a coyote watches from an enclosure as a cow walks past at the Millville Predator Research Facility in Millville, Utah. The number of coyotes killed under a state bounty program criticized by wildlife advocates grew by more than 1,000 animals in 2015, a year that saw the shooting death of a well-known wolf that was mistaken for a coyote and another apparent wolf killed in a snare.

SALT LAKE CITY — A Utah state program that pays a bounty for dead coyotes brought in about 1,000 more carcasses last year, despite criticism after the shooting death of a well-known wolf mistaken for a coyote, according to a Division of Wildlife Resources report.

Officials say the 16 percent increase is likely related to growth in the overall coyote population. Heavy summer rains meant their main prey, jackrabbits, were in steady supply, allowing more animals to survive and breed, Leslie McFarlane, the state's mammals program coordinator, said.

Wildlife advocates, though, point to research indicating that coyote populations compensate for hunting with larger litters, more surviving pups and the addition of solitary animals.

A total of 8,192 coyotes were turned in to state wildlife officials between July 2014 and June 2015, the report shows. The $50-per-coyote program paid out a total of $409,600 during that period.

The number of hunters participating dropped a bit this year, but the bounty numbers increased overall because individual hunters turned in more animals — nearly half of them brought in more than five coyotes.

The program came under scrutiny after a wolf protected under the Endangered Species Act was shot and killed when a hunter in southern Utah mistook her for a coyote. The long-ranging 3-year-old female, Echo, had captured the attention of wildlife advocates across the country because she was the first wolf seen near the Grand Canyon in seven decades.

Advocates called the December 2014 death heartbreaking, and said state officials could have saved the animal if they'd suspended the coyote program after a sighting of the wolf was reported to the state.

State officials disagreed, saying the sighting report was inconclusive and that the hunter wasn't participating in the bounty program.

In November, a second apparent wolf was found dead in a coyote snare near the Idaho border, in an area where wolves have been removed from the endangered species list. Biologists are conducting DNA tests to make sure it wasn't a dog hybrid. That hunter was a participant in the coyote bounty program.

The deaths show the coyote bounty program puts wolves in the cross hairs, said Michael Robinson with the Center for Biological Diversity.

"The Utah bounty program is basically encouraging thousands of people to go out and kill wildlife willy-nilly," he said.

Officials said the program has reduced the number of coyotes killed by state workers as part of control efforts, and authorities tell hunters to work primarily in the spring to stave off overbreeding.

Utah doesn't track the size of the overall coyote population, and it's difficult to pinpoint all the reasons why the number of carcasses turned for a bounty increased in 2015, but the numbers appear to reflect natural wildlife cycles, McFarlane said.

"It's not out of line with the historical records," she said.

The predator control program has also helped mule deer, animals popular among big-game hunters that state lawmakers wanted to protect when they increased the coyote bounty to $50 per animal in 2012.

The mule deer population hit a 20-year high in 2014, said Justin Shannon, the state's big game program coordinator, though they've also benefited from other factors like habitat restoration and mild winters.