Yellowstone National Park staff killed a newborn bison after a visitor helped it cross a river, an apparent rescue effort that prompted the calf's herd to reject the animal, park officials said Tuesday.?
The calf had been separated from its mother when the herd crossed a river in a northern section of the park on Saturday, Yellowstone said in a news release.
As the calf struggled to cross the river, the man approached the animal and pushed it up from the river and onto a roadway, the release says.
Visitors later saw the calf walk up to cars and people and follow them, according to the release.
Park rangers tried repeatedly to reunite the calf with the herd, but the efforts failed, according to the release, which notes that interference from people can cause wildlife to reject their offspring.
After the failed reunification efforts, park staff killed the newborn"because it was abandoned by the herd and causing a hazardous situation by approaching cars and people along the roadway," the release says.
The release pointed to park regulations requiring visitors to stay at least 25 yards from all wildlife, including bison, elk and deer, and 100 yards from bears and wolves.
The park website has a page explaining why it doesn't rescue animals after they're injured or when they become separated from their mothers.
The park said law enforcement officers are seeking more information about the incident.
It isn't clear if the man who pushed the animal onto the roadway could face possible criminal charges. A park spokesperson did not immediately respond to a request for comment.