Mega-fauna

By Michael Ellis

Every time I’ m on a safari in Africa there are a couple of questions that always arise. As we are looking across the vast plain of the Serengeti, a scene that looks much like eastern Wyoming but for the thousands of wildebeests, gazelles, and zebras, someone invariably asks, – “How come we don’t have this many animals in the U.S.?” The answer is – we used to. 150 years ago there were 50 million buffaloes in the middle part of our continent. In the desire to wipe the Plains Indians right off the map, the US government reduced that large biomass of animals to about 600 individuals. 50 Million to 600. Whatta waste.

The next question is more complicated. After seeing enormous elephants, 18′ tall giraffes, huge hippos, and towering ostriches, people wonder why North America doesn’t have such large animals. Well, I say, we used to and it wasn’t really that long ago.

18,000 years ago during the last Ice Age mastodons and mammoths weighing 13 tons and roamed the Arctic Steppe. Everything was big here, perhaps as an adaptation against the cold. There were giant peccaries, giant armadillos, giant beavers, giant capybaras, giant sloths and giant long horned bison. And the predators were also large – saber toothed tigers, the American lion – much bigger than its African cousin, the dire wolf and probably the fiercest predator to roam the earth since T. rex- the short faced bear. 1500 pounds of pure carnivore terror. Lest we forget the birds there was even a raptor with a wingspan of 16 feet!

So what happened to all these fantastic animals? In a word – humans. As the Ice Age ended a land bridge formed and allowed our ancestors to cross from Asia into a world that had not known fear of humans. Within a very short period of time every single animal that weighed more than 220 lbs. – horses, camels, sloths, mastodons- in all 30 genera were killed off..

But in Africa where humans originated and have lived for several million years, the large animals evolved defenses against us. So that is why Africa has elephants and we don’t.

This is Michael Ellis with a Perspective.

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Skills

Posted on

August 6, 2009