Costa Rica has four species of monkeys (called monos in Spanish), three of which live in the Children’s Eternal Rainforest. How can you tell them apart? Here’s a photo of each and some fun facts from MCL Board Member Mark Wainwright’s outstanding and beautifully illustrated field guide, The Mammals of Costa Rica:
Name: Mantled howler monkey (Alouatta palliata)
Range: Found all over Costa Rica, including in the Children’s Eternal Rainforest, Howler monkeys are the most common monkey in Costa Rica and can be found on both the Pacific and Caribbean slopes up to elevations of about 2,500m.
Fun Facts: With a call that sounds more like a lion’s roar, this larger monkey (up to 11 lbs and 20″ in length) can nonetheless be remarkably stealthy. While in some areas, it is common to be woken in the morning by their communications, at other times you might not even see the troupe of Howlers passing silently through the trees over your head until one of them drops a seed or nut at your feet (or on your head).
Unique among monkeys for its diet, the Howler feeds heavily on the leaves of dozens of types of trees. Because of the difficulty presented by digesting the cellulose from which leaves are made, no other New World mammal except the sloth makes leaves a primary element of their diet. Their reliance on this low-energy/high-digestive-cost food means they move relatively slowly and take lots of naps, spending up to 75% of their day and all night at rest.
Name: Central American Squirrel monkey (Saimiri oerstedii)
Range: In Costa Rica, mostly found in large bands scattered throughout the South Pacific region. It is not a resident of the Children’s Eternal Rainforest (but we love it anyway). These animals are very endangered in Central America because they have lost habitat to oil palm and banana plantations and were for years exported for the pet trade and biomedical research.
Fun Facts: Squirrel monkeys form larger troops than any other New World monkey (20-70 individuals) and forage for insects, fruit, flowers, and small animals in the middle and lower levels of the forest.
They have developed an ingenious method of rousting and feasting upon tent-making bats (a fascinating species in its own right, these bats make tents for themselves by folding leaves around their bodies before sleeping): When Squirrels find a folded leaf that they suspect contains a bat, they jump on the leaf from above and tackle any bat that doesn’t escape quickly–making it dinner. Yum!
Name: White-faced (or White-throated) Capuchin Monkey (Cebus capucinus)
Range: Capuchins are common up to 3,000m on both the Pacific and Caribbean slopes, and are found all over Costa Rica, including in the Children’s Eternal Rainforest.
Fun Facts: While it was long thought that only Old World primates (orangutans, chimpanzees, and other apes–like us) used tools, researchers have discovered that Capuchins do as well–using sticks as clubs (to beat off snakes, for example) and making tools to get at food. Their brain is proportionally larger with respect to their body, which may play a role in the development that allows for this advanced functionality. Many other monkeys, such as the Squirrel (with its little Squirrel monkey brain) do not have this advantage and, possibly, as a result, cannot make and use tools.
Capuchins are on the small side (16″ long and about 6.5 lbs) and their prey tends to include beetle larvae, caterpillars, and other insects, but they’re plucky and have been known to tackle birds, mammals, lizards, frogs, and shellfish. Other naughtiness includes raiding coati nests so effectively that in parts of Guanacaste coatis have been almost entirely prevented from raising any young.
Name: Central American (or Black-handed) Spider monkey (Ateles geoffroyi)
Range: Living in loose communities of up to 40 individuals, these delicately boned, long-limbed monkeys with prehensile tails are relatively uncommon but can be found throughout Costa Rica, including in the Children’s Eternal Rainforest.
Fun Facts: Spiders primarily eat fruit (they are frugivores) and spend most of their day foraging in the upper canopy. Their communities are divided into several bands, which roam and sometimes sleep separately. Newborn monkeys ride on their mother’s chest for the first two months, and then on her back until they are able to move independently (usually about another month later). When a young monkey reaches a gap in the canopy too wide for it to cross, an adult will stretch itself across the void so that the younger monkey can travel across its back.
Sadly, Spider monkeys are what you might think of when you think of an “organ grinder” monkey; and indeed these monkeys have been heavily poached for the wildlife trade. They also are large and good tasting, so they are prone to being hunted. They are now on the endangered species list (CITES) and this has helped reduce pressure on the populations, but great care must be taken to protect them because their reproductive rates are slow and repopulation takes a great deal of time.