We were traveling by pontoon boat down the Sierpe River that flows through the largest mangrove swamp of the Osa Peninsula of Costa Rica into the Pacific Ocean. Me, several other photographers and our boat captain and a guide were all scanning the shoreline for birds, crocodiles, iguanas, snakes, monkeys–you name it. The Osa Peninsula is one of the most biodiverse places on the planet. I’m not sure who first spied the baby Green Heron (Butorides virescens), still covered with down, struggling among the mangrove and ficus roots along the bank. But no sooner had the shout gone up and…