A recent article in the United Kingdom's Daily Telegraph discusses a study published in the current issue of the journal Endangered Species Research, which found that of 24 large mammals that once migrated in the hundreds of thousands, six of the migrations have been completely eliminated and the rest severely diminished.

Many different species of animals across the globe are being impacted.  Not surprisingly, the study found that bison in North America have been badly affected:

Bison, which once thundered through the North American grasslands MidWest, are now so depleted that they only migrate within the Yellowstone and Wood Buffalo National parks.

The causes of the declining migrations include converting land to agriculture, building fences, constructing roads and railways, oil exploitation, and over-hunting.

The article also notes that "scientists are particularly worried by the 'devastating effects' of increasing measures to stop diseases from wild animals spreading to livestock, by erecting long fences and culling wildlife."

This devastating practice is at the epicenter of the current mismanagement of Yellowstone National Park's bison population.  (See here, here, and here for more information.)

Yellowstone's bison are the only continuously wild, free-roaming population of bison that remains in America.  Yet the government agencies in charge continue to slaughter, haze, and confine them to the Park, which artificially suppresses their natural migration patterns.

Yellowstone National Park is only about fifty miles south of our office here in Montana, and I spent a day in the Park fly-fishing a couple of weeks ago.  

I was working my way up the Firehole River -- a good distance from the nearest road -- when I came across a large, magnificent herd of bison. 

It had snowed that morning, and the bison were grazing in a huge meadow along the river.  I crossed the Firehole to give the bison plenty of space as I continued upstream. 

I worked my way upstream for a few hours, immensely enjoying my day among the hatching mayflies and rising trout.  Many of the bison that were grazing in the meadow also followed the Firehole upstream in the afternoon.  Dozens and dozens of bison passed me on the bank; their destination known only to them.

Later that afternoon, as I was heading back downstream to my car, I came to the large meadow where the bison had been browsing.  It was empty; the bison had moved on. 

All that remained was a gorgeous meadow -- and the image implanted in my memory of hundreds of bison, including many newborn calves, grazing in a snow-covered field in the Yellowstone backcountry in early June.  It is something I won't soon forget. 

And I hope that image never becomes, as it has for so many other species, a relic of the past.

Here are some pictures from that memorable day:

Bison in the Meadow

Bison in the Firehole River

Bison on the Bank of the Firehole River

Firehole River

Bison Meadow Sans Bison