YELLOWSTONE NATIONAL PARK, Wyo. (AP) — A man who picked up a bison calf in Yellowstone National Park caused it to be shunned by its herd, prompting park officials to kill the animal rather than allow it to be a hazard to visitors.

Park officials quickly defended the decision to kill the newborn bison.

“We made the choice we did not because we are lazy, uncaring or inexpert in our understanding of bison biology. We made the choice we did because national parks preserve natural processes,” the park said in a statement posted Tuesday on Twitter.

Park officials’ options for dealing with the animal were limited, according to the statement, which said bison must be quarantined before being sent to conservation herds outside the park. A bison calf abandoned and unable to care for itself is not a good candidate for quarantine, the statement said.

The calf became separated from its mother when the herd crossed the Lamar River in northeastern Yellowstone on Saturday. The unidentified man pushed the struggling calf up from the river and onto a roadway, park officials said in a news release.

Human interference with young wildlife can cause animals to shun their offspring. Park rangers tried repeatedly to reunite the calf with the herd but were unsuccessful.

At one point, visitors saw the calf walking up to and following cars and people. This created a hazard, so park staff killed the animal, according to the news release.

It’s the latest example of Yellowstone visitors getting in trouble or hurt after approaching bison. Park officials euthanized a newborn bison after a similar incident in 2016, when a Canadian man and his son put the calf in their SUV, thinking they could rescue it.

The man pleaded guilty. He was fined $235 and ordered to pay $500 to the Yellowstone Park Foundation Wildlife Protection Fund.

Bison have gored several people in Yellowstone in recent years, often after they got too close to the animals.

Many of Yellowstone’s larger animals — including bison, which can run up to 35 mph (55 kilometers per hour) and weigh up to 2,000 pounds (900 kilograms) — are deceptively dangerous, even when they are just grazing or resting.

Park rules require visitors to keep at least 25 yards (23 meters) away from wildlife including bison, elk and deer, and at least 100 yards (91 meters) away from bears and wolves.

Park officials are investigating the bison calf incident. The suspect was a white male in his 40s or 50s who was wearing a blue shirt and black pants, the statement said.

The calf’s body was left on the landscape, similar to the 25% or so of Yellowstone’s newborn bison that don’t survive, park officials said in the Twitter statement.

“Those deaths will benefit other animals by feeding by feeding everything from bears and wolves to birds and insects. Allowing this cycle of life to play out aligns most closely with the stewardship responsibility entrusted to us by the American people,” the statement said.