The bureaucrats, ranchers and advocates are united in their belief that wild horse reproduction is the problem, not the reproduction rate.
If you’re at 3X AML, you’re not interested in slowing the growth rate but reversing it.
Given that AMLs are small relative to the available resources, the conflict between wild horses and privately owned livestock can be alleviated by confining the ranchers to their base properties in a year-round off season and expecting them to pay (OMG) the going rate to feed their animals, but that’s taboo in the Love Triangle and fringe groups like the Wild Horse Fire Brigade.
The decision earlier this week to test two new fertility control drugs is just the latest attempt to eradicate the pests in favor of the most noble and deserving nonnative species on America’s public lands.
What’s the difference between long-lasting contraception (that can be achieved with just one dose) and sterility?
Not much. But you can’t call it sterility and you can’t refer to the experiments as sterilization research. Off limits.
You can talk about self-boosting mares, but not in mixed company.
Using the Rule of 72 for a quick estimate, you need a growth rate of 72 ÷ 5 = 14.4% per year to double the herd size in five years. If the death rate is six percent per year, the required birth rate is 20.4% per year.
You need a growth rate of 18% per year, and a birth rate of 24% per year, to double the herd size in four years, as some land managers and wild horse detractors claim.
What do the data indicate? Consider the results from last year’s roundups that started on or after July 1 (after foaling season). These figures are based on the daily reports, which may differ slightly from the cumulative totals posted to the gather pages.
The weighted average birth rate was 17.4%, implying a growth rate of 11.4% per year.
The death rate this year may be higher than normal, as previously discussed.
On average, one foal was born to every 2.6 mares. Each mare produced 0.38 foals.
With the probability of a mare delivering a live foal slightly more than one out of three, the advocates target every animal they can get their sights on.
Why? Because their goal is one of the S-words.
Hopefully their enmity and mettle will appeal to the bureaucrats and ranchers, who, like them, want the wild herds minimized and domestic herds maximized.
RELATED: Foal-Free Friday, Busting the Myth of Reversibility Edition.