Horses of the Badlands

On the north side of I-94, near the town of Medora, ND, you’ll find Theodore Roosevelt National Park.  It consists of three areas: North Unit, South Unit, Elkhorn Ranch Unit.

A video overview appears on this page.

Wild horses roam the South Unit, along with bison and other wildlife.  The horses, of course, are subject to ‘humane’ management practices.  Excess horses are offered for adoption through the General Services Administration.  The North Dakota Badlands Horse Registry maintains a database of adopted horses and advocates for WH preservation in TRNP.

The park is managed by the NPS, not the BLM.

These Women Are Not WH Advocates

Video posted June 2017 by liberal/modernist/progressive NBC Left Field.  At least they admit their bias.  Shows PZP darting of mares.

You want to build a house?  Buy some land.

New factory or chemical plant?  Get some land.

You want to graze livestock?  Run to government.

Farming and ranching are two of the most respectable professions out there.

But get your own land.  Like everybody else.  And leave the horses alone.

More on Colors

Suppose you visited an HMA in Nevada and found a band of 16 horses near a water hole.  Six had a base color of red and ten were black.

According to the post on horse colors, 25% of horses should be red, 75% should be black.

In your sample, 6/16 = 37.5% are red.

Are red horses over-represented in this group?  Is there discrimination toward black?

Let’s start with the genetics of base color.  There are four possibilities in the Extension Locus: EE, Ee, eE, ee.  Any combination containing E will be black (because it’s dominant).  Therefore, 3/4 = 75% of horses should have a base color of black, 1/4 = 25% should be red.

The expected proportion of red is a property of the population of all horses, not samples of sixteen.  The range of variation of red in samples of sixteen is found by calculation:

Mean ± 3 Standard deviations

Given that a horse is red or not-red, the mean and standard deviation can be supplied by the binomial distribution:

np ± 3 × Sqrt[np × (1 – p)]

where p = .25 and n = 16.

The upper limit of variation is 9.196.  Round ‘inward,’ toward the mean, to 9.

The lower limit is -1.196.  Round to the nearest non-negative integer, 0.

In groups of 16, you should expect to find anywhere from zero to nine red horses.  In this example, six is well within the expected range of variation.  No sign of trouble here.

Now suppose you went to the Kiger HMA in Oregon and found no red horses in a group of 25.

The expected range of variation is 0 and 12 so you might conclude that red is not under-represented in that area.  However, your subject-matter knowledge tells you the HMA is managed primarily for grullos and bay duns so the low number of reds is not surprising.

Imagine you just read a report on the results of a wild horse gather, where 101 mares and fillies were rounded up along with 79 stallions and colts.  Were the helicopter pilots targeting females?

Show your work.

Hint: p = .5 and n = 180.

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