Sunday, August 3, 2014

Giant Bison: Prehistoric Animal of the Week

Hear that rumbling?  It's this week's prehistoric beast stampeding in!  By request, let's make way for Bison latifronsBison latifrons, or commonly referred to the "that giant prehistoric bison", lived in many parts of the United States during the Pleistocene as far back as 200 thousand years ago.  It went extinct rather recently, only about 20 to 30 thousand years ago.  This woolly mammal was similar in many ways to the modern bison we can observe around us today except for the fact that it was bigger...quite a bit bigger in fact.  This beast was over eight feet tall at the shoulder and weighed over two tons!  Its horns were particularly impressive.  The width of the skull of one of these mega-mammals could be up to seven feet across!  With stats like that, Bison latifrons may have been the largest bovid (family that includes buffalo, bison, cattle, goats...double-hoofed mammals with horns that say "moo" or "baa".) that ever lived.  It probably needed to be, too.  Remember, this animal had some pretty scary neighbors, including mammoths, rhinos, giant sloths, glyptodonts, sabre-tooth cats, short-faced bears (biggest bear...ever.) and even humans.

A male Bison latifrons having an intellectual conversation with a heron over some still water 30,000 years ago in what is now Texas, USA.  Reconstruction by Christopher DiPiazza.

I kind of have a soft spot for bison.  I get to see them every day when I go to work at the zoo.  I have gotten pretty close to them, as well when the veterinarian comes for their yearly check ups.  When I was in college, I got the amazing experience of volunteering at an actual bison farm.  (Yes, it was in New Jersey.)  Just like cattle, the bison had to be rounded up every so often so they could be weighed, measured, and given vaccines or any other sort of medication each individual may need.  If you have ever worked on a farm, you know that rounding up domestic animals like cattle or pigs is difficult enough.  Now imagine doing it for an animal the size of a bison!  These guys were tough.  I remember my job was to pull a rope tied to a giant metal door behind each animal as it ran through a chute.  I needed to make sure only one bison at a time went through.  If one decided to stop in the middle, there was really nothing I could do until the bison decided to move on her own!  Manually pushing a cow works just fine but a bison will turn you into mush if you do so much as get in there with one, especially if they are already stressed from being rounded up.  When one would kick the metal door, the whole structure shook and my hand, which was gripping the rope attached to that door would feel just a tad tingly for a good while after that.  Also keep in mind these beasties were all female (about 1,000 lbs each).  The males are even bigger (roughly 2,000 lbs).  Now imagine their relative, Bison latifrons, which was even bigger than that!

Bison latifrons skull on display at the North Dakota Heritage Center.  Check out how wide those horns go!

Unlike today's American bison, which live in herds by the thousands (and at one time in recent history much more) there is no evidence that Bison latifrons lived in such large herds.  Another difference is that Bison latifrons lived in places pretty far south like Texas and Southern California.  This was a mammal that didn't mind it a little on the warmer side sometimes.  It definitely wasn't just a bigger copy of its modern relatives.  The giant horns, present on both males and females could have been used to deter potential predators if need be but their primary function was probably for within the species.  Fighting by locking horns for dominance is common, not just with bison, but with bovids in general.  Another way Bison latifrons may have displayed was by what we call wallowing.  This is when a bison will roll on its back in a patch of dry dirt, creating a large dust cloud around it.  The bigger the dust cloud, the bigger and more powerful the bison making it is.  This behavior can be observed in modern bison.  They also do this to rid themselves of surface parasites, and to help shed their winter wool as they molt.  If you would like to see what this looks like in action simply check out that youtube video down there.



Oh, and one last thing.  A bison is NOT the same as a buffalo.  Huge pet peeve of mine is when I overhear zoo visitors call them buffalo.  White American settlers used to refer to bison as "American Buffalo" because the closest animal they could compare them to was an actual buffalo, which live in Africa and Asia.  The two bovids, although related, are not the same animal.  Remember that!


Water Buffalo from Asia.  Not a bison.

American Bison from America.  Not a buffalo.

That is all for this week!  Feel free to comment below or on our facebook page


References

Bell CJ (2004). "The Blancan, Irvingtonian, and Rancholabrean mammal ages". In Woodburne, M.O. Late Cretaceous and Cenozoic Mammals of North America: Biostratigraphy and Geochronology. New York: Columbia University Press. pp. 232–314. ISBN 0-231-13040-6.

Kurten, B; Anderson, E (1980). "Order Artiodactyla". Pleistocene mammals of North America (1st ed.). New York: Columbia University Press. pp. 295–339. ISBN 0-231-03733-3.

Scott E, Cox SM (2008). "Late Pleistocene distribution of Bison (Mammalia; Artiodactyla) in the Mojave Desert of Southern California and Nevada". In Wang X, Barnes LG. Geology and Vertebrate Paleontology of Western and Southern North America. Los Angeles: Natural History Museum of Los Angeles County. pp. 359–82.

Systematic relationships in the Bovini (Artiodactyla, Bovidae). In Zeitschrift für Zoologische Systematik und Evolutionsforschung, 4:264–278., Groves, C. P., 1981. Quoted in Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), Don E. Wilson & DeeAnn M. Reeder (editors). 2005. Johns Hopkins University Press: "Bison".

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