The secretive island of Barro Colorado (BCI) is home to one of the most studied rainforests on Earth. Because of its extraordinary plant and animal diversity, for almost a century top scientists have traveled here to observe, experiment, and conduct research in this pristine habitat.Recently the El Niño phenomenon has caused a severe drought during the midst of the wet season. Scientists rely on climates data collected by Steven Paton, the director of the Smithsonian Institute's Physical Monitoring Program, and his team. The rainforest usually gets more than 20 inches of rain in a single month, but this year is proving to be one of the driest on record. The extreme dry weather could cause damage to food sources for animals and may lead to starvation.When the rain finally arrives, life begins anew. Glass frogs descend from the canopy and call out for a mate on leaves overhanging water. The glass frog's natural biological design is perfect rainforest camouflage. A green topside matched with a translucent underbelly makes the frogs very difficult to spot. Both male and female glass frogs watch over their eggs until the young tadpoles have hatched and dropped to the water.One scientist familiar with the cycles of life in the rainforest is Dr. Jackie Willis. For over 34 years Jackie and her husband Greg Willis have traveled to BCI to conduct a mammal census. The census is one of the longest running projects on the island. Jackie and Greg walk every trail on the island at a snail's pace recording all the mammals that call BCI home.Dr. Roland Kays, working with leading researchers and Smithsonian Tropical Research Institute (STRI) fellows, has launched a radical new study called "Food for Thought". The project compares several species, attempting to determine if brain size is related to the ability to remember food sources. The study is also looking at how animals navigate between feeding sites - trying to find the most efficient routes. They have placed GPS tracking collars on white-faced capuchin monkeys, spider monkeys, and kinkajous. These special devices track and download the data associated with each animal's movement. The project is off to a great start, but can the team find all the animals needed to do a true comparison?With each study resolved, new questions arise. Despite decades of research, there are still secrets to uncover in this complex and mysterious environment.