The Amazon Basin, Ecuador
At first it looked like a stack of old car tires, piled haphazardly in a tree in the middle of the river. When we got closer, I could see a greenish-brown diamond pattern along what would have been the centre of the tread. Then it moved. Its head, smallish compared to the rest of its body, was about the size of a large fist. Then the anaconda slid slowly into the river. We watched for almost two minutes as the entire six or perhaps seven metres of it disappeare...