AmericanBison_PrairiesandBison_Eidson_Jim_CelesteTX_19October2000_Reel2114.mp3
Jim Eidson [00:00:00] One ecologist I talked to some years ago over the fact that, you know, every blackland prairie remnant that we know of is an artifact of its management, you know, by humans: the cutting of hay primarily being the disturbance regime. And he said, "Well, you know, you throw in fire and you throw in buffalo and whatever comes out is what it's supposed to be there." And that's kind of oversimplifying a little bit.
Jim Eidson [00:00:24] But we wanted, here a couple of years ago, wanted to start experimenting with bison grazing. And in 1999, in May, we brought in 15 bison bulls on 114 acres, that's back to the east here. And let them go out there and kind of graze unmolested for about two months. And then we packed them up and sent them home.
Jim Eidson [00:00:51] We looked at that in terms of kind of being the shakedown cruise that, that we wanted to know that the fences would hold, and what their dietary preferences were going to be, and kind of what their behavior was going to be in that setting.
Jim Eidson [00:01:06] The ecological impact was pretty neutral at that light a stocking rate, for that short of time. There were some trails and a little trampling, and we found out they liked the big bluestem more than anything else.
Jim Eidson [00:01:17] And, but really, the way that we think that bison grazed in the prairies was that they would move into an area in large numbers, in tight family groups, that the density within a given acre of bison would be relatively high for a short time period because of the fact that these little family groups were surrounded by predators - buffalo wolves, that type of thing.
Jim Eidson [00:01:42] And so to try to replicate this, this year, 2000, we brought 30 animals in, again in May, and took the same 114 acres and then installed electric fence to develop 5- to 10-acre paddocks. So the animals were kind of compressed in on small areas to intensify the grazing effect. That grazing would run from 5 to 10 days and then they would move to the next one, never to return to that, that paddock that they had grazed. So we greatly intensified that, that grazing effect.
Jim Eidson [00:02:17] One of the things that, that's pretty evident that even at that that intensity of grazing, that density of animals, there's still some selectivity that goes on. The bison select grasses over anything else. They don't eat forbs during the early growing season. But then again, they trample everything. It's very democratic. Everything gets trampled. But only the grasses get eaten.
Jim Eidson [00:02:41] The next thing that we found out is that toward the end of the grazing season, well, toward the end of the summer, our grazing period there, from about mid-July on, that their dietary preference begins to shift over to to browse and to forbs. So they begin to eat trees and also to molest trees more. They horn them. They roll on them. They trample them. And so that was encouraging as well.
Jim Eidson [00:03:08] The bison had been considered a keystone species in the prairie, along with fire, that they were extremely important there. Others have even called them, "prairie engineers" because they did more than just kind of impact vegetation. They, they had the impact on the soil through trampling, through wallowing. They reshaped gullies in places from hoof action.
Jim Eidson [00:03:33] So I think that, I think we're encouraged by this. Right now, after the end of the grazing season, you know, you can definitely tell a major disturbance has happened on these paddocks out there. But I think that the push that's taken place there is a push in the succession, directing succession in the right way.