Federal environmental authorities have launched an investigation after a photograph appeared Tuesday showing two men next to an American buffalo they had killed in Coahuila.

The photo was taken from the Facebook and Instagram accounts of a hunting ranch near the northern border city of Piedras Negras that offered hunting trips for protected species such as American bison, as American buffalo are also known, and white-tailed deer.

The newspaper El País reported that several photos of bison that were apparently hunted between 2011 and 2015 were posted to the social media accounts of the Buena Vista ranch. The ranch’s Facebook and Instagram accounts, as well as its website featuring more images of slain wild animals, have now been deleted.

The circulation of the image showing two men posing next to a slain bison, one of whom is toting a firearm, came just days after Environment Minister María Luisa Albores celebrated the successful reintroduction of a second herd of the large mammals, in northern Mexico, writing on Twitter that the “beautiful animals” have returned to the plains of Coahuila after an absence of almost 100 years.

El País said there was no evidence that the buffalo that appears in the photo was reintroduced as part of Mexico’s conservation efforts but the hunting of the animal was nevertheless heavily criticized on social media.

The federal Environment Ministry said in a statement that it checked its records and determined that authorization to hunt bison had never been granted to the Buena Vista ranch.

The ministry said it was collaborating with the environmental protection agency Profepa and the Coahuila government to “clarify the facts,” adding that if it is proven that bison were illegally hunted those responsible will be held to account.

“The government of Mexico is committed to the conservation of this species and its habitat,” the statement said. “We are working for its recovery and … the inquiries to clarify the facts and enforce the environmental law will continue.”

Tens of millions of American bison once roamed Mexico, the United States and Canada but by 1880 there were only about 1,000 of the mammals in the wild in Mexico due to destruction of their habitat, disease and hunting, according to the National Commission for Natural Protected Areas (Conanp).

A herd of 23 bison from the Wind Cave National Park in South Dakota was reintroduced to the Janos Biosphere Reserve in Chihuahua in 2009, while a herd of 19 of the mammals from Janos was released into the El Carmen nature reserve in Coahuila last year.

“The establishment of herds in Mexico contributes significantly to the recovery of the species on a continental scale,” according to Conanp.

Source: El País (sp)