Rare white animal missing from national park after 'one-in-a-million' event

Visitors to Yellowstone National Park had delighted in photographing the striking animal. But sightings have suddenly ceased.

A white bison calf with two adults at Yellowstone National Park, United States.
The birth of a white bison at Yellowstone National Park was celebrated as a one-in-a-million event. Now it's missing. Source: Jordan Creech

A rare white calf that was born inside a national park this year is missing. The last images snapped of the bison were taken on June 4.

Its birth was considered a one-in-a-million event and was cause for celebration among Native American tribes. Although such occurrences were more common when the species numbered between 30 and 60 million animals.

In the 19th Century plains bison were hunted to the brink of extinction. An iconic photo from 1892, when the herd was reduced to just 456 wild animals shows the scale of the slaughter. It shows two men posing in front of a towering pile of skulls in the US state of Michigan.

Breeding efforts have resulted in a steady recovery. Today there are 20,500 in conservation herds and an additional 420,000 commercially bred animals.

Two men pose with a pile of bison skulls in Michigan 1892. The picture is black and white and faded.
Two men pose with a pile of bison skulls in Michigan 1892. Source: Burton Historical Collection, Detroit Public Library

Related: Zoo beefs up security after birth of extremely rare alligator ‘worth millions’

The Yellowstone National Park population where the white bison was born fluctuates between 3,000 and 6,000 animals.

This herd is regularly culled because they can spread a disease called brucellosis that can contaminate livestock. Bison do not naturally carry the bacterial infection — it was spread to them by cattle farmers in the early 20th century.

On Friday, US Parks and Wildlife confirmed the white bison was probably leucistic, a mutation that can be genetic or environmental. It said park visitors, professional wildlife watchers, commercial guides and researchers had reported the sightings of the animal, but it had been almost a month since the last one.

An aerial photo of bison at Yellowstone.
Today there are between 3,000 and 6,000 bison in Yellowstone. Source: Getty

“To date, park staff have been unable to locate the calf. To our knowledge, there have been no confirmed sightings by park visitors since June 4,” it said in a statement.

Love Australia's weird and wonderful environment? Get our new newsletter showcasing the week’s best stories.