My Year of Darwin (2/28/2014)

"A person, on first entering a tropical forest, is astonished at the labours of the ants: well-beaten paths branch off in every direction, on which an army of never-failing foragers may be seen, some going forth, an others returning, burdened with pieces of green leaf, often larger than their own bodies." Charles Darwin, Voyage of the Beagle

Darwin is speaking of leaf cutter ants. There were two, at least, species of leaf cutter ants in Manaus. These ants cut leaves into pieces, let them fall, then carry them off to the underground nest. There the leaves are fed to a fungus that uses the sugars in the leaf as a source of energy and the ants eat the fruiting bodies of the ants. Ants create the ideal environmental conditions for the fungus in terms of temperature and humidity and attack competing fungi.  New queens take pieces of the old fungus to start new colonies. 

At camp in Manaus, leaf cutter have raided our food stores and taken off with beans, farinha, and spaghetti!  Their underground liars are immense and the effects of leaf cutters on tropical forests cannot be overstated. Leaf cutters prefer newer growth and will go out into pastures to defoliate young trees thus keeping pastures as pastures and slowing succession. 

Here's a shorter video here:

Here's a longer video here (really cool):