We saw a lot of animals on our Costa Rica trip that were interesting, but did not make it into the blog yet. Here are some pictures with ID’s where we have them. If you know any of these species, please add identifications by posting a comment and I’ll update the post with the new ID and credit to you.

Hermit crab on the beach.

These little hermit crabs were everywhere! Hermit crabs use the discarded shells of other animals and have to change their shell as they grow. If you search really hard, you can find naked hermits upgrading their shells on the beach. They are in the animal kingdom’s superfamily Paguroidea, but we do not know what family or genus. UPDATE: Marie has identified this little creature as Coenobita compressus in the family Coenobitidae via a comment posted on the blog.

"Lefty" crab (Uca sp.) in the mangrove mud.

We affectionately called these little crabs “lefty” because most of the ones we first saw had their pincher arm on the left (although upon further inspection of the population, many were “righties”). Thanks to a comment from Ana, we now know that they are a species in the genus Uca.

Land crab just outside the research station.

Pacific land crabs (Cardisoma armatum), also known as rainbow crabs and parrot crabs, come to the Pacific shore to reproduce before returning to their primary homes in the forest. They are very brightly colored in their youth, but fade as they age.

Sand dollar on a piece of beach driftwood.

We need even more help with the identity of this little creature. It is a sand dollar that washed up on the shore of Playa Grande and all we know is that it is in the order Clypeasteroida.

Sea snail from the surf sand in Keren's hand.

Sea snails are gastropods that live in saltwater. We saw a few different sea snails in Costa Rica. This one was scooting along just under the sand as the surf was coming in at Playa Grande. We have no idea what species it is, so please help us out.

Butterfly in the forest of Cerro Morro.

We saw many butterflies, but I was only able to photograph a few of them. A beach butterfly appeared earlier in a post by Ely. This one was about halfway up Cerro Morro flying low in the forest and is another species we have yet to identify.

Heron fishing in the mangrove.

This beautiful heron (Ardea species, family Ardeidae) was a common sight during our fieldwork. We greatly enjoyed watching this majestic bird fish and fly.

Male howler monkey making his way through the canopy.

The final animal of this post is one that we heard often and saw a couple of times, the mantled howler (Alouatta palliata, family Alouattinae). These monkeys are found throughout Costa Rica and the males make a sound somewhere between a barking dog and a mad pig to alert others of their presence. It works. You can hear them many kilometers away. This is a monkey you don’t want to aggravate – if you do, they will pee or poo on you! However, howlers are rarely disturbed by people and for the most part tend to ignore them.