Why are there no large mammals in South America? (no bison, bears, hippos, elephants, moose, tigers, etc?)?

Question

I know there are some odd medium sized mammals like llamas and tapirs and some kind of huge rodent but I can't remember ever hearing of any large (mammal) predators or grazing animals. Why no bison on the Pampas? No hippos in the Amazon? I can't think of anything bigger than a llama! Is this really the case or am I just an ignorant norte americano?

Answer 1

The jaguar is the third largest cat 4th if you count the tigers as two species. Tapirs weigh in at several hundred pounds. Sloth bears are south American black bears (a little smaller but not much). Peccaries. Giant snakes and 250 pound rodents called capybaras. The Patagonian cavie is large but not truly huge.

But mostly you are correct, South America does lack the really huge animals. The reason is the Amazon. Most of South America is heavily forested. If you have heavy forests the really large animals have little room to move and little feed to eat. If you think of the large animals and where they live the vast majority live on the plains. S America has no huge areas with plains.

Answer 2

The question should really be why are animals in Africa so large, and why were dinosaurs so large for that matter. For the former no information anywhere on the net I could locate. Animals in North America are larger than South America because animals in a temperate climate tend to be larger than animals in a tropical climate. The cold means they need to be bulkier to insulate themselves to stay warm. For example, Siberian tigers are larger than Bengal tigers. Insofar as why animals are so large in Africa perhaps the Sahara cutting them off and many, many millions of years more of evolution in an isolated area could be a part of the explanation. This explanation suggests animals in South America are more recent models with less adaptations to their environment than African animals.

Answer 3

Actually there is a mammal that is accepted as large but not over the edge. There are two large mammals found in the Amazon. The giant otter and the Manatee.

Answer 4

I thought it was because of the tropical climate - harder for big animals circulatory system to keep cool but through a Y! search I found out large mammals were wiped out by "volcanic torrent."

http://www.sciam.com/article.cfm?chanID=sa006&articleID=E2377583-E7F2-99DF-34F02FC32CA56B50&pageNumber=1&catID=2

Answer 5

The huge rodent is a Patagonian cavie. Is Jaguar in your vocabulary? You need to read child. There is more out there than you can imagine.

Answer 6

There are Jaguars in S. America..they are a rather large predator.