In the tangled vines that shrouded the shoreline, what appeared to be partially submerged logs suddenly blinked and slid beneath the surface, revealing themselves as caimans—South American alligators. Rhythmic eddies in the water betrayed the passage of anacondas, which can weigh as much as five hundred pounds. The men were by now well acquainted with the razor-toothed piranha; every time they were forced to wade while maneuvering their sluggish dugouts, they would be at risk of attack.
