Two men who appeared in a viral video in which one lured a squirrel to the edge of what appears to be the Grand Canyon and kicked it off the edge, are being pursued by US authorities.
However, park officials fear it is unlikely they will find the pair who are believed to be French.
“Right now they are working on it,” said Grand Canyon National Park spokeswoman Kirby-Lynn Shedlowski on Monday.
“They realize that [the video has] been seen by a lot of people and that there's some sensitivity to treatment of wildlife.”
The short clip which was posted on YouTube shows a topless, barefoot man in shorts and a straw cowboy hat laying a trail of food at the edge of a canyon. He then puts on one of his shoes and kicks the squirrel into the air. Meanwhile, another similarly-dressed man looks on.
Shedlowski said the geographical features of the canyon in the video appear to match part of the iconic US National Park in Arizona.
On Monday, the authorities have attempted to contact the YouTube user who uploaded the video, but they have not received a response.
Grand Canyon Chief Ranger Bill Wright said that no one had reported the incident at the time, but he instead heard the allegations when the video was brought to the park's attention on Saturday.
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The park has since received messages from people appalled by the behaviour of the men, and urged authorities to hold him accountable.
“I think they took an opportunity to get something on video, which is really foolish,” said Wright, adding he doesn’t believe the video is a hoax.
If the men are found, they could face a charged of disturbing or harassing wildlife — a federal petty offense that carries a maximum six months in jail and or a $5,000 fine.
It is unlikely that rangers will attempt to put forward the incident as a case of animal cruelty, added Mr Wright, as that would require them to retrieve the squirrel and prove that it was injured or had died.
That task would prove difficult, considering the average depth of the Grand Canyon is 1 mile (1.6 km). In addition, some of its rock outcroppings, trails, and other ledges don't guarantee that something going over the edge would fall a mile below, Wright said.
Squirrels are commonly seen at the Grand Canyon, where the creatures have become accustomed to tourists, and climb on their laps, beg for food and ransack backpacks.
Park officials discourage visitors from petting or feeding wildlife because the animals can bite or attack.
Additional reporting by AP