Tropical forests usually have very shallow soils, and partially in response to this trees develop buttresses for structural support. The buttresses on some trees can be up to 10 feet tall and extend 8-10 feet from the trunk. The myriad of lines and forms made by buttresses constantly fascinated me, and I have albums of photographs that are essentially natural studies in line.

I found a group of these baby caimen in a small swamp at the edge of the forest. The mother didn't appear to be around, so we picked one up to take a few photographs. Baby caimen squeak loudly when you pick them up. This one was making a lot of racket, so we kept eyeing the waters nervously for some larger eyeshine. These caimen aren't normally aggressive, but at a full grown length of 5-6 feet, I didn't particularly want to upset the mother in the middle of the night.

Red Eyed Treefrogs (Agalychnis calydryas) generally come out in masse to mate on certain nights in the summer, and when they do the branches over their breeding ponds can be covered with pairs like this. They attach their eggs to leaves and branches over the water, letting the tadpoles develop in safety for a while before they hatch into the more dangerous waters below where they have to face shrimp and other predators.

I was surprised at the beauty of the metamorphs of this frog. A metamorph is the stage between a tadpole and a frog, after they have grown legs and left the water but still have a tail.

This is probably one of my favorite photographs from the rainforest. Not because it is a stunning image, but because it captures the essence of diversity in a small space. I don't set up shots, and I found these four animals just like this on the same Heliconia flower. The tufted insect on the right is a fulgorid, and on the left is some species of cockroach. The frog is a Tink Frog, one of the most ubiquitous frogs in Corcovado National Park. Their calls are the main sound that you hear outside at night. I've even heard them calling during an intense hurricane.

Bothriechis schlegelii - Eyelash vipers hunt birds and bats, waiting in ambush for them on small branches where they like to alight. They are exceptionally difficult to find, because they are so well camouflaged. I found this one by almost grabbing the branch it was coiled around. (It's head is in the upper left)

Hyla ebracatta

Adventure books and old accounts of tropical rainforest often describe the forest as a massive tangle of undergrowth, so dense that it is impossible to go very far without a sharp machete. These descriptions were usually based on how the forest appears from a boat on a river in the rainforest. In fact, once you get inside an old growth tropical rainforest the forest floor is remarkably clear and easy to navigate, because the dense canopy above does not allow enough light for much undergrowth. Palms are one of the most common plants under the rainforest canopy. the fishtail palms in this picture are linking the top of a steep ridge in the middle of undisturbed primary forest.

Centrelonella granulosa - Glass frogs are named for the transparent quality of their skin. If you turn them over, you can see through the skin on their belly to their internal organs. Although the transparency is less obvious from the top, in this photograph you can still see some of the internal organs through the side and an artery in the legs.

Glass frogs typically lay their eggs on leaves overhanging small streams. The males have the unusual behaviour of guarding the eggs and cleaning them regularly to keep fungus from growing on the outside. When the tadpoles are mature, they wriggle out and drop down into the stream. If it is a bad year, and the stream is dry, they are out of luck.

Many frogs in the tropics attach their eggs to leaves above the water. Waters can be filled with predators like freshwater shrimp and this strategy gives the tadpoles a head start by letting them grow big enough to outrun predators before they even hit the water.

Heliconia are one of the most common understoy plants in the new world tropics. Many species like this one specialize in gaps created by fallen trees.

I found this little slot canyon on a trip down one of the rivers in the park. It was not at all obvious from the river, but we could hear the sound of rushing water in the background, so we explored up it looking for a waterfall. The slot was only 2-4 feet wide - so narrow that it is barely visible from the forest above. A few dozen bats flew out as I walked in.

This falls sits at the end of the narrow slot canyon in the last picture. From above it looked as though the creek just disappeared in the middle of the forest.

Hyla ebracatta

I found this scene on the beach after a very large hurricane hit the park. During the hurricane there was up to two feet of water rushing over the forest floor in some places near the ridges. The next day I went down to the beach and found it covered with several feet of debris that had washed out of the forest. This tree had been stripped of most of its outer bark, revealing the blood-like color of its sap. Among the debris were some small animals that had been washed out of the forest, including a salamander that is rarely seen.

The Cat Eyed Snake (Leptodeira septentrionalis) is often mistaken for a baby Fer-de-lance, one of the most dangerous snakes in central America, because their markings are very similar.

Leptophis ahaetulla - The thing in the back of this snake's mouth are the toes of a treefrog that it had just swallowed.

I photographed this magnificent tree from Corcovado National Park dozens of times. It wasn't the largest or the oldest tree in the park, but something about it struck me as particularly beautiful. I think that one of the things that made it such a wonderful tree to photograph was that it sat in a clearing in such a way that just beyond it the forest was laid out like a painting - a rare situation in the usually cluttered rainforest.

Caluromys derbianus - Unlike most opossums, Wooly opossums have furry tails. You can see just how furry in this photograph. This little one was snacking on coconut in a tree near the lab at Sirena Biological Station.

Anolis polylepis

Eleutherodactylus ridens

Thryothorus semibadius - Appropriate for its name, I found this nest in a branch hanging over one of the streams that borders the Sirena Biological Station.

Buteo magnirostris - One of the most commonly seen raptors in the Central American Tropics. In Corcovado National Park, they frequently hang out in the tall trees along the side of the airstrip.

Ajaia ajaja

Hyla rosenbergi

I think the name of this frog is pretty funny. Apparently they do defend their nests pretty vigourously. They males dig out depressions in the mud, which they will defend viciously until they find a female to lay eggs in it. After that, the eggs are on their own.

Sphenomorphus cherriei

Bradypus variegatus - Yes, the sloth's fur is green! Sloths get moss growing on their back, because they don't move around much (I suppose that they don't groom much either). They also have a moth that lives in the fur in their back which eats the moss. That species of moth hasn't ever been found anywhere else, and they lay their eggs in sloth scat. Interestingly, sloths climb down trees to relieve themselves, which has always seemed to me like a particularly bad adaptation for something that moves so slowly. Useful for photography, however, since I found this one when he was heading back up into the trees after such an excursion.

Eleutherodactylus stejnegerianus

Thecadactylus rapicaudus

Scinax eleachroa

Corallus hortulanus