I'm preparing for a talk at a soils conference in North Dakota and have been reviewing how ruminants like the American bison grazed. Their behavior can help us understand effects of various grazing schemes today on the forage and soil.
It also makes for an interesting history lesson and can illustrate how we have changed the environment since the time of European settlement.
To get an idea of how bison and other large herds of ruminants grazed, consider this early story.
An army corporal named Eugene Bandel went with a survey party to demarcate the southern boundary of Kansas in summer 1857. He wrote in his notes that his party never camped a single night without water throughout the trip, and never went without grazing for the horses and mules except one two-day period when they crossed a swath where a bison herd had passed. He described the swath of buffalo grazing as decimated, with no fodder of any value left behind. Today this would be characterized as "severe" grazing. It is the "bust" side of the boom-and-bust grazing that Montana grazier Ray Banister uses.
Bandel also described finding adequate water about every 15 miles all the way across that state, clear to the dry western border where rainfall averages only about 15 inches. This today is semi-desert. Such occurance of water is absolutely not possible today. The water cycle is too poor and most creek beds and arroyos in the westernmost region are lucky to have water in them when it rains.
Further, he wrote about seeing black bear and elk near the salt flat area of the Cimarron River, which is near Freedom, Oklahoma. (Frontier Life in the Army, Eugene Bandel, 1932, edited by Ralph Bieber)
In particular, Bandel's description of bison grazing should be valuable to us. It generally matches descriptions from Africa I have read about grazing by migratory wildebeest, specifically decimation behind the animals and long periods of recovery.
In many cases, and certainly in the case of the American bison, wolves were said to be ever-present, following the herds and seeking to devour any who appeared weak.
This seems to be common herding and grazing behavior for ruminant animals, which were the primary occupants of lower-rainfall and/or more erratic rainfall regions all over the world.
Early settlers in the Great Basin of North America reported seeing herds of pronghorn antelope literally in the millions, and similar mass numbers of several species of antelope in Africa were often reported as European settlers moved onto the continent.
There are also some indications that mountain sheep, another ruminant, may have moved in large herds through the Rockies in America.
This story shows an interesting relationship between other species and the bison: A Texas cattle drover wrote about an experience with bison in 1871 while driving a herd of Longhorn cattle north to Kansas.
"On a plain about halfway between the Red Fork and the Salt Fork we had to stop our herds until the buffalo passed. Buffalo, horses, elk, deer, antelope, wolves and some cattle were all mixed together, and it took several hours for them to pass, with our assistance, so that we could proceed on our journey. I think there were more buffalo in that herd than I ever saw of any living thing, unless it was an army of grasshoppers in Kansas in July 1874," he wrote.
Considering his comments on herd size, it's worth recognizing that 1871 was the beginning of the massive herd slaughter on the Southern Plains, but well into the period of herd reductions by Indians and whites alike. By 1872 Dodge City was well known as the primary outpost for buffalo hunters and hide shipping.
Even more impressive is a description from the Northern Plains. U.S. Marshal X. Biedler of Montana told a reporter that between Poplar Creek and Miles City he had for 70 miles been in the middle of a herd of bison that had to number in the "millions." This kind of report to that point had been more common in the far Northern Plains where the white hunters had been slow to go and the Indians had been tougher for the army to defeat. By 1884, hide hunting for bison was pretty much a dead industry. The slaughter of 20 million or more animals had lasted less than 20 years.
To feed such numbers of wild ruminants took millions of tons of dry matter, so herds of such mass could never return to any area quickly, thereby overgrazing was prevented.
This lengthy and variable recovery time was the thing missing from grassland management for 10,000 years, and this has led to the steady decline in native rangelands worldwide, and to increasing more dependence on medium-quality, short-stature forages selected from already overgrazed ranges of the world.
Wetter -environment grazing
An alternative grazing behavior appears to come from resident animals in wetter environments. Some of these were ruminants like the impala in Africa, but many were hind-gut fermenters such as horses and zebras, rhinoceroses, elephants, mammoths and mastodons.
Both types of grazing animals -- ruminants (fore-gut fermenters) and hind-gut fermenters -- have unique digestive tracts suited to their habitats.
Ruminant animals are better suited to eating smaller quantities of relatively higher-value forage.
The hind-gut fermenters tended to live more commonly in high-rainfall areas which were mixed forest and grassland. Their digestive systems are well suited to processing high volumes of low-quality forages.
By nature, it could be argued they tend to live a more sedentary lifestyle, yet early European settler reports of zebra and rhinoceros in Africa indicated they once could be found in herds of thousands. This indicates they had to move about, too, but probably not over such large distances, and their return to former grazing grounds was probably more frequent and less erratic. Their effects on the forage likely were more frequent defoliations, but the nature of long-shooted native tallgrasses and desireable forbs tells us these plants had to have full recovery at some point.
This information challenges the modern grazing manager with his ruminant cattle in high production areas to pressure the forage with higher numbers and more frequent defoliations, yet at some point still allow full recovery after grazing, since all grasses have the same response to defoliation.
Incidentally, I'll be talking about this and more at the soils conference in Bismarck, North Dakota, during the "Regenerating the Soil with Diversity" conference Nov. 7-8. It looks like a star-studded line-up of speakers. To learn more or register by Oct. 31, go www.menokenfarm.com.