We know that caiman, anacondas and piranha thrive here. In fact, one of the excursions we didn't have time for was the piranha fishing (you tie little bits of meat to the end of a string -- dip it into the lake and pull out a piranha -- which the guides then cook for lunch). It's impossible to see into this murky water, but we can tell something is definitely living and moving around in there -- and we keep our hands and fingers inside the boats, just to be safe.

As we paddle, our guides shout out animals and directions (using the 'clock' method -- "squirrel monkey 3 o'clock!; heron 11 o'clock! howler monkey overhead! etc.). As our heads spin trying to figure out where to look, some of us realize that as a generation of digital clock owners, we're not very good at this. We catch glimpses of monkeys and a variety of birds -- including the Stinkbird (pictured) -- with a blue face and attractive crest. Our guide says that this bird smells and tastes bad, so no one hunts or eats it. (Maybe that's why this bird is less shy and easier to photograph than the more delicious animals that hide better.)

Troops of small monkeys pass high overhead, moving fast. See them? Hint -- there are 2 monkeys in this picture.