Mules are pretty amazing. In this very special LFPL Teen Blog post, we’ll explore key points of history and biology – as well as thorny ethical issues – all at the same time through the lens of these famous hybrid equines. (Language warning? Or something. It’s all clean in context, but we do need to talk extensively about donkeys, especially jacks.)

The Definition of a Species

A species is all of the living things that can make babies together, whose babies can also make babies without any problems like diminished fertility. That’s it. Easy, actually. That’s why a gray wolf and a toy poodle are members of the same species, even though they look so different. Wolfdogs are a thing, and absolutely can go on to have lots of puppies. Like so:

Chinstrap Penguins (for example) and cabbages are not members of the same species, because they can’t make babies. That’s also why Chinstrap penguins are not the same species as Little Blue Penguins. Almost always, two species can’t interbreed at all, let alone produce living offspring. But sometimes, two species are close enough that they can produce healthy babies together, but those babies have trouble reproducing.

This brings us to equines (the horse family) and mules.

 

Introducing Mules

There are lots of equine hybrids, actually. You may have heard of mules, hinnies, and even zorses, but one of my favorite equine hybrids is the otherwise fairly rare and obscure zebroid stallion zebra X jenny donkey hybrid, called either a zedonk, a zebronky, a zonkey, or a zebrass.

Majestic! Stripes, upright mane, solid gray body coat, and all of the untamed aggression and cantankerousness of a zebra with a donkey’s thoughtful stubbornness, which is exactly why they’re fairly rare. There’s no demand for this animal, except as a curiosity. It certainly isn’t going to carry you or your luggage.

Mules, though, were wildly popular, and continue to be the most commonly bred equine hybrid. They’re reliable to breed, and generally have the best traits of both horses and donkeys. Horses are fast, but tend to panic. Donkeys are strong and sensible, but are usually smaller than horses. A mule (if you choose the parents wisely) can be in the size range of a horse, strong, fast, and sensible. A mule is the offspring of a male donkey, and a female horse. To make all this easier to understand without too much typing, here’s some basic terms!

Horses:

Baby horse – foal

Immature female horse – filly

Immature male horse – colt

Mature female horse – mare

Castrated male horse – gelding

Mature male horse – stallion/horse (We call all horses horses, even though technically it’s just the stallions that are horse horses. Just like we call all cows cows, even though it refers to specifically female cows, which is kind of redundant. Similarly to dogs: only male dogs are dog dogs. I’ll probably do a whole post on the English language and all our weird animal terms. Also, different breeds take different amounts of time to grow up, so the exact years in which a horse is a filly vs a mare or colt vs stallion can change, depending on the breed. Just like humans take different amounts of time to hit puberty or something. Some breeds are just late bloomers, or early ones, depending.)

 

Donkeys / Asses:

Baby donkey – foal

Female donkey – jennet / jenny

Male donkey – jack

Castrated male donkey – john / gelding

 

To get a mule, breed a mare to a jack. That’s much easier to say.

 

Mules

Baby mule – foal

Female mule – molly

Intact male mule (super rare – why put up with behavior issues if they’re sterile anyway?) – horse mule

Castrated male mule – john mule

 

The trick with mules is that most jacks are tiny, since most donkeys are also tiny. This is about average size for a regular donkey:

What if you want a big strong mule? There are also breeds of donkey that exist just for making mules with specific traits, like size, such as American Mammoth Jackstock (and, in the case of the Poitou Mule, a specialized breed of horse, too.) This is where stuff gets WEIRD.

 

The Famous Poitou Mule

In France over the 18th and 19th Centuries, mules were so important to agriculture that an entire breed of horse AND an entire breed of donkey were developed purely so that farmers could get large, strong mules to pull their farm equipment.

This is a Poitou Horse, or a Poitevin Mulassier (Poitou Mule-maker):

This one’s even a horse horse. A stallion. His literal only reason to exist is to look pretty at horse shows and produce mares who will produce mules. Historically, anything else a Poitou Horse could do (especially a horse horse), like pull carts or even provide meat, was just a nice bonus. This animal is effectively a living gene bank.

There’s also the Poitou Donkey, a giant-sized breed with a long shaggy coat. This is a jennet and her foal at a show:

Again, since the jacks are the ones that people use to make mules, jennet Poitou donkeys are also living gene banks, like stallion Poitou horses.

So, that’s two breeds (each from a different species) of equine, each selected over time just for making mules. When you do breed a Poitou donkey jack to a Poitou horse mare, you get a gorgeous, versatile Poitou Mule:

They’re beautiful, really. You can ride them:

You can drive them:

They’re very photogenic:

Tragically, though, farmers have moved on to tractors, rather than mules. Now, heavy breeds of horse and donkey are generally much less popular than they were in the past, and mules along with them. The Poitou mule exemplifies this trend: as breeders strive to redefine what their donkeys and horses can do, all three breeds – the Poitou Mule, the Poitou Donkey, and the Poitou Horse – are very rare. All that has to happen for mules to stop existing is for people to quit breeding them: their genetic bank exists not in the population of mules, since those don’t breed, but in the population of horse and donkeys. Since DNA degrades over time, the best way to keep genes available is to keep the population that carries them going. But, even if you could straight resurrect members of extinct species Jurassic Park -style, in the end, that just sets up another pile of problems, and maybe not the kind of ethical dilemmas you might anticipate…

 

The Ballad of Idaho Gem / Idaho Star / Utah Pioneer

The setup: cutting-edge science, a wealthy entrepreneur who will “spare no expense” in pursuit of his passion, and a potentially lucrative payoff. This story isn’t a novel or a movie about what could happen with cloning technology. It’s about what did happen, over a decade ago, with the first batch of cloned equines.

Don Jacklin, the President of the American Mule Racing Association, wanted a way to reproduce his best racing mule. Since mules are sterile, this meant enlisting the aid of a crack team of equine reproduction scientists and veterinarians, and cloning his champion mule. Idaho Gem, Idaho Star, and Utah Pioneer were the genetically identical results of this successful quest to clone the first equine. Technically, due to being born first, Idaho Gem was the official first equine clone.

So, as clones of a champion racing mule, did the three duplicates go on to dominate the sport? Interestingly, no. Idaho Star apparently never was that into running, Utah Pioneer remains an educational exhibit entertaining schoolkids, and Idaho Gem – although good at racing – didn’t live up to Jacklin’s expectations as a champion. He eventually retrained for gymkhana.

I guess it makes sense, really, that clones of the original aren’t like the original exactly. After all, the three cloned mules are effectively identical triplets of each other, and identical siblings can be very different from each other in all sorts of ways, including personality.

Genetics literally isn’t everything, and it certainly isn’t destiny.