Speed demons

A couple of days ago, I posted a question for wildlife enthusiasts among the readership:  “Pronghorn Antelope can run 55-60 mph over open country, and they can sustain that speed for several minutes.  That means they can run much, much faster than any of their North American predators (wolves, coyotes, mountain lions, bears, etc.).  Why would they need to run this fast?

Below is a really good clip of running Pronghorn Antelope from the BBC archive. (Click on the “back” arrow to get back to this post.)   Running full out, the animal extends its back fully as all four feet leave the ground and then flexes its back as the forelegs touch the ground for the next stride, and the hindlegs bunch under it to give it the next powerful thrust forward.

ARKive video - Pronghorn running

One reader suggested their speed was a means to put distance between the Pronghorns and their predators in the open country, which is certainly true, but not the primary reason that Pronghorn are such speedy runners.

Predators today of pronghorn antelope include mountain lions, wolves, coyotes, bobcats, and golden eagles which may take newborn or young antelope. Here’s a look at their predators’ speed stats.

Pronghorn Predator Maximum speed
Mountain Lion 40-50 mph (may be overestimated)
Coyote 42-45 mph
Wolf 38-40 mph
Bobcat 30 mph

None of today’s native North American predators can come close to a sprinting Pronghorn on the open plain; their only chance of success would be an ambush or boxing the animal into a closed canyon.  It’s more likely that these predators attack just the very young, very old, or very feeble in the Pronghorn herd.

So why does the pronghorn run so fast, second only to the fastest mammal in the world today, the cheetah?

The answer lies in what/who used to chase them 8-10,000 years ago, when the North American megafauna looked very much different than it does today (to read what I wrote about this topic earlier; please click here).

The American Cheetah looked like its African cousin, but became extinct in North America about 10,000 years ago.

There were at least two species of American Cheetah, but they became extinct in North America about 10,000 years ago, shortly after humans entered North America over the Bering Sea land bridge.  Being chased around the plains by one of these carnivorous speed demons selected for speedy, endurance running in the antelope.

Like cheetahs, Pronghorn have elastic spines that help elongate their stride, large lungs and hearts to facilitate oxygen extraction and delivery to their working muscles, and a unique ability to make quick changes in directions, by as much as 90 degrees in a single leap.  To accomplish the latter, cheetahs whip their tails around like a rudder in the air; I’m not sure how Pronghorn do it.  What marvels of evolution!

Pronghorn male and female

9 thoughts on “Speed demons

  1. Wow. Cheetahs are one of my favorite animals and I always stop to see them when I visit the National Zoo in Washington DC. I had no idea that Pronghorns were almost a match for the cheetah in speed or that there were cheetahs in America at one time. Thanks for sharing the cool video too that looks like it was filmed from a helicopter of aircraft. It was amazing to see the pronghorns running so effortlessly like that.

  2. I like to put on my rose colored glasses and think that birds sing because they are so happy and pronghorns run because they love too, but I know there are other reasons. This was real interesting. Thanks Sue!

  3. Just a couple of notes from an old paleontologist. The North American “cheetah” probably shares a common ancestor with the cougar, and is just convergent with the the African cat. And people were on this continent at least 15,000 years ago, although they may have arrived as early as 40,000 years ago. The pronghorn – love them. I lived in Wyoming for 8 years and enjoyed watching them crawl under fences they could easily jump. A friend’s grad student, David Carrier, studied their physiology and running speed for his dissertation.

  4. Years ago, I did a semester long project on pronghorn and back then there wasn’t a good explanation of why they evolved to be so darn fast in the common literature. Then a few years ago I think I bumped into what you mention above in a Jared Diamond book. Tho, I had forgotten it. Thanks for the reminder and the cool video. These are some of my favorite animals.

    • Thanks for visiting the blog! Glad you enjoyed the post. You have an interesting blog as well, and I am a fan of many of the books/authors you have been reviewing. I’ll be watching for more of your interesting posts.

      • That’s very cool of you to check out my book blog. We also have a little farm blog that you might enjoy – mammoth donkeys, pondering goose eggs, wacky succubus weeds – RoundTableFarms.com.

Please Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s