"Mangrove" is a term generally used for many of the species of trees tolerant to the salt of the tropics. Thus, mangroves are a group of unrelated woody plants that grow on protected tropical coasts.

   In general, the species of mangroves are small trees, very tolerant to the immersion in salt waters. These trees colonize the shores, the trapped sediments and gradually construct a dense and organic soil. They represent an important nesting site for birds including the beautiful Scarlet Macaw and a shelter and nutrient spot for many fish and invertebrates.

   Although these formations may seem very calm, there is a lot of activity going on. You can find amongst them, different types of mangrove crabs and any type of snail shells, most of them, active at night.

   In the Pre-Columbian years various indigenous groups migrated to these coastal zones and used the benefits they obtained from the mangroves, such as salt, fish, crustaceous and mollusks as trading objects with larger populations. Nowadays, the mangroves of Costa Rica have been declared areas of Forest Reserve and thus shall be protected.

   Mangrove roots constitute an important and unusual marine habitat. Oysters, sponges, corals, algae and many other organisms commonly live in the roots of the red mangrove. Because of the leaf falling and subsequent microbial and fungal decomposition, the mangrove swamps are extremely important for marine productivity.

   There are five different species of mangroves, and four (Red, black, tea and white) are found in the Tárcoles River and Guacalillo area. The mangrove forests at this area are one of the most important feeding sites for resident and migratory Shorebirds, Seabirds and large water birds. Cormorants, frigate birds, pelicans and numerous herons and egrets are commonly found in mangrove swamps. Kingfishers, pigeons and a variety of passerines frequently feed here.