Here are some pictures that show some reasons that I think this.
this picture shows a skull with anemia a deases caused by malnutrition top left. This one shows the unfinished building this is a big piece of evidence that they left suddenly center. This one is a farmer telling about how the crops are becoming less and less productive another reason to think that they were starved out top right.

I believe that the Mayas ran from their cities because of crop failures that led to malnutrition. On of the reason I think that the were malnutrition is that there is, in the city of copan a monument that is only half finished and the last date on it is 822 and it seems that no monument was built after that. One of the reasons that they evacuated their cities so quickly is that there might have been a big drought that parched the crops plus the fact that crops in Mexico are producing less and less. I believe that this caused famine and people fled to try and please the gods. The malnutrition I believe is proven because of the fact that the cities seem to have been evacuated very quickly. So I am led to believe is that the cities were abandoned quickly and because of malnutrition and crop failure.

A sitting feline representation. Between his front paws he tarnishes a human head and he is eating it.

A Chancay ceramic funerary urn.

These Chimu ceramic could be used for daily use and for ceremonial offerings.

The moche often represents the daily life of the moche. It represents many things.

many people think that this signifies burial passages.

in this paracas textile the rich usualy had more themn the commeners

the chavin revolutionized the way people did art in latin america.

The Incas were excellent at making ornaments with gold, copper, silver, and bronze.

here is some music that you can listen to from these cultures.

http://www.youtube.com/watch?v=CvTiMnxAxdw&feature=player_embedded#