03/30/2021
Very good information.
“Reality is merely an illusion, albeit a very persistent one.” ~Albert Einstein
Let’s take a moment and ponder the what if’s! There are some who believe that gathers in TRNP should be stopped and no more birth control. Who wouldn’t want that?
What if the gather is stopped? What if birth control is stopped?
Well that was the brain worm I woke up to one morning….and this is what I came up with, the numbers, the reality, almost, in a hypothetical exercise.
Starting in 2015 (the year that I began working in TRNP on Fly Without Wings, in addition to working for CSU as a research tech on the contraceptive project, and as a volunteer for the park) I took the number of horses who were on the birth control study the beginning of 2015—148.
I then pretended there were no gathers between 2015 through the end of 2020, six years. We documented 177 live births.
Now, not counting the current 2021 foals, and subtracting the attrition of older horses, there would be 300 horses in the park, give or take a few as my attrition number for older horses may be off by one or two.
Wow…that doesn’t seem too bad right? 300 horses? Until one looks at the forage load on 46,158 acres, shared with 200—500 bison, guessing 200 plus elk (there was an elk reduction in 2012 of 468 animals), and who knows the multitude of mule deer and pronghorn, in a semi-arid environment where less than 15 inches of moisture fall a year, and currently (as of March 30th) under a severe drought warning that is likely to persist or worsen through the spring and into summer. Now the added pressure of the potential for 300 horses instead of the approximate 170 (I apologize for not knowing the exact 2021 population number) the number becomes a bit more daunting.
As you will see, from the attached rudimentary map, that not all of those fenced 46,158 acres are utilized by the horses.
The blue area is intended to highlight where they mostly range, in addition to highlighting what could be deemed as available grasses for sustenance. On the map you can make out the topography. For those who have been to TRNP you understand that not much grazing happens on those buttes and ridges.
Some stallions, especially those along the southern border—Georgia’s Boy, Teton, Roosevelt, and Wild Rye rarely, if ever, actually leave their ranges. They get by, somehow. They know where the hidden pockets of water are, Roosevelt has access to a stream as long as their is available moisture, Teton hits many hidden areas of water, and Georgia’s Boy has the Little Missouri. Their band numbers are relatively small, Teton sporting the largest harem at eleven.
Those other bands? Flax has his well-established range, but I did witness his band so thirsty, when we were last there the first of March, they were drinking slush from the side of the loop road and got spooked when a tourist rolled up to them to get their picture, they went away thirsty.
Trooper, he has his area and not much pressure from other bands, unless it’s Marty hounding him to get his mares back. Same with Coal, he has a large area he roams and frequents the Little Missouri for his water source, again Coal has a relatively small harem.
That leaves those eleven bands that tend to range together—from the eastern boundary of Fryburg to the interior, to Lindbo Flats in the summer. On good moisture years it all works at the current numbers, but if those numbers were doubled to that hypothetical 300, then what?
But wait—the hypothetical if there were no gathers number was easy to calculate, but that dreaded reality just kept hounding me, the reality is that most of the mares over the last six years have been on birth control.
Now it gets interesting.
Doing some research I found that the control mares on the birth control study (the mares who were not given the vaccine) in the park had an 84% foaling rate. Yes…I didn’t make that up, 84%.
Now let’s start working the data, hypothetically.
Let’s pretend no mares are on birth control from 2015 through the end of 2020, six years.
First—I determined how many breeding age mares there were in 2015.
Second—then researched the mortality rate for foals.
Third—determined the percentage of fillies versus c**ts born,
Fourth—determined the mortality rate for adult horses.
Fifth—Start working through the next six years, year by year using the percentages to determine end of year data.
At the end of the sixth year (2020)—I will leave this number right here for you to ponder—854 horses.
There is never a one size fits all solution in managing our beloved wild horses and today’s exercise in numbers was only to show how horses can reproduce quickly to levels that would decimate the landscape they need to thrive on, along with the other ungulates that share it with them.
Again, it takes a willing public, a community, to work with not against management to ensure these wild beauties find their new forever homes. Thank you for being a positive voice for this wild herd!
