Pounds of horse edible grass on a short grass praire - Ask Extension
I recently read the book "The Contested Plains" by Elliott West. It is a great book about pioneer expansion into Kansas and Colorado. West makes the p...
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Pounds of horse edible grass on a short grass praire #381176
Asked January 04, 2017, 6:02 PM EST
I recently read the book "The Contested Plains" by Elliott West. It is a great book about pioneer expansion into Kansas and Colorado. West makes the point that Indian ponies, alone, were ruining the prairies before white settlers arrived. This was especially true in winter. So what I was looking for is 1) How many pounds of horse edible grass can be found per acre in a short grass prairie environment. How many ponds of grass does an Indian pony need per day to survive. 2) Same question for Long Prairie grass environments. Also, it allegedly takes 1-2 acres of pasture to feed a horse. Is this per year, per month or per day? West also claims that starving horses would eat cottonwood bark and twigs. My experience with horses is that they are very finicky eaters. Will horses eat cottonwoods?
Arapahoe County Colorado
Expert Response
Hello,
Thank you for the intriguing and interesting question. Most of my questions are very technical and this is a nice change. I am familiar with West's work - interesting as it is - and would like to make some comments.
First, any discussion of Great Plains ecology must center on the bison. At its peak (i.e. 1000 BCE), the bison herd could number 30-40 million animals, and ranged annually from Texas to Alberta. However, this population was very unstable. The fossil record contains two recent periods of complete absence of the bison herd in Colorado (5000-2500 BCE and 500 - 1500 CE). For centuries following these droughts we assume that overgrazing was rampant. So it is not an issue of the introduction of the horse. Rather, the bison population never fully recovered from the drought of the Medieval Warm Period, and the rangeland was especially vulnerable as a result.
Additionally, it would be literally impossible for the size of the horse herd to rival the main bison herd - it is simply not supported in the anthropological/historical record. Lewis and Clark, Pike, Fremont et al. didn't see massive herds of horses on the Plains, they saw massive herds of bison. A major critique of West's work is that it advances the ethnocentric idea of the 'noble agrarian', i.e. that Western settlement somehow 'saved' the Plains. What I am trying to say is: the range was already in bad shape before the horse arrived, and the bison population was crashing (or was recovering, based on your frame of reference). Horses were a 'flash in the pan' in terms of paleobotany- they were around for a few hundred years, while bison were present for hundreds of thousands of years.
In regards to your question about forage intake: horses, dependent on age/weight/condition, eat 800 - 1200 lbs forage per month. This will very seasonally a small amount. However, it should be the same regionally. This is where horses get the nickname 'hay-burners'. Considering that shortgrass prairie produces 800 - 1000 lbs/ac per year of forage, I would say that stocking number is on the low side. Also that assumes equal access to water. So I would say it takes closer to 20-25 acres to support one horse per year (and that is high quality rangeland). In the wetter mixedgrass, you could probably get 1500/lbs/ac/year forage, which would mean 15-20 acres per year.
In regards to your palatibility question, I agree that horses are picky eaters. However, feral horses have a very diverse diet - in Nevada, they eat sagebrush and cheatgrass. Also, cottonwood shoots (green spring growth) can be high-quality nutrition for game early in the season. So I don't think it would be a stretch for horses to eat cottonwood shoots. However, I think that the bigger issue would be tree availability. All of the historical accounts of exploration in this region (Spanish, French, American) describe the prairie as treeless. This was likely due to fire and wood removal, as well as bison grazing. Early pioneers had to live in sod houses and burn manure for this reason.
Thanks again for your question. Please feel free to contact me via email (<personal data hidden>) or on the phone<personal data hidden>), and we can discuss further.
Thank you for the intriguing and interesting question. Most of my questions are very technical and this is a nice change. I am familiar with West's work - interesting as it is - and would like to make some comments.
First, any discussion of Great Plains ecology must center on the bison. At its peak (i.e. 1000 BCE), the bison herd could number 30-40 million animals, and ranged annually from Texas to Alberta. However, this population was very unstable. The fossil record contains two recent periods of complete absence of the bison herd in Colorado (5000-2500 BCE and 500 - 1500 CE). For centuries following these droughts we assume that overgrazing was rampant. So it is not an issue of the introduction of the horse. Rather, the bison population never fully recovered from the drought of the Medieval Warm Period, and the rangeland was especially vulnerable as a result.
Additionally, it would be literally impossible for the size of the horse herd to rival the main bison herd - it is simply not supported in the anthropological/historical record. Lewis and Clark, Pike, Fremont et al. didn't see massive herds of horses on the Plains, they saw massive herds of bison. A major critique of West's work is that it advances the ethnocentric idea of the 'noble agrarian', i.e. that Western settlement somehow 'saved' the Plains. What I am trying to say is: the range was already in bad shape before the horse arrived, and the bison population was crashing (or was recovering, based on your frame of reference). Horses were a 'flash in the pan' in terms of paleobotany- they were around for a few hundred years, while bison were present for hundreds of thousands of years.
In regards to your question about forage intake: horses, dependent on age/weight/condition, eat 800 - 1200 lbs forage per month. This will very seasonally a small amount. However, it should be the same regionally. This is where horses get the nickname 'hay-burners'. Considering that shortgrass prairie produces 800 - 1000 lbs/ac per year of forage, I would say that stocking number is on the low side. Also that assumes equal access to water. So I would say it takes closer to 20-25 acres to support one horse per year (and that is high quality rangeland). In the wetter mixedgrass, you could probably get 1500/lbs/ac/year forage, which would mean 15-20 acres per year.
In regards to your palatibility question, I agree that horses are picky eaters. However, feral horses have a very diverse diet - in Nevada, they eat sagebrush and cheatgrass. Also, cottonwood shoots (green spring growth) can be high-quality nutrition for game early in the season. So I don't think it would be a stretch for horses to eat cottonwood shoots. However, I think that the bigger issue would be tree availability. All of the historical accounts of exploration in this region (Spanish, French, American) describe the prairie as treeless. This was likely due to fire and wood removal, as well as bison grazing. Early pioneers had to live in sod houses and burn manure for this reason.
Thanks again for your question. Please feel free to contact me via email (<personal data hidden>) or on the phone<personal data hidden>), and we can discuss further.
