Dark Four-eyed Opossum - Philander melanurus

The Dark Four-eyed Opossum is one of our most commonly encountered mammals on the tour. They are called Four-eyed Opossums because of the conspicuous white spots which are positioned above each eye.

These small marsupials frequent creeks, rivers and swamps where they feed on frogs and freshwater shrimp.

Other food items preferred by Four-eyed Opossums may include lizards, bird eggs, fruit, nuts and nectar. 

Female Dark Four-eyed Opossums have a well developed pouch where they carry their young for about two and a half months.

Litters may number between two and seven larvae. After the young opossums emerge from the pouch, they will remain in a nest created by their mother and continue nursing for another two weeks. 

Four-eyed Opossums reach sexual maturity at seven months of age and usually only live for about two years. Their range extends from southern Mexico to Paraguay and northern Argentina.

 White-nosed Coati - Nasua narica

Coatis are some of Costa Rica's most frequently observed mammals. Large groups, of up to 40 individuals, may  be observed making their way through the forest. Although they are active during the day, we often  see lone males at fruiting Malay Apple, Mango, and Breadfruit trees during The Night Tour.A

Packs are made up of females and immature individuals. Male Coatis are solitary and are only allowed near the pack during their breeding season. At this time, the male is accepted by the females and will mate with each member of the group.

Soon afterwards he will be expelled from the group, possibly because males are known to kill the newborns.

Pregnant females will break away from the pack about three to four weeks before giving birth. They usually make a leafy nest in a palm tree or a tree crevice.

Females give birth to two to six young and they will remain in the nest until they are about four weeks old. Once they reach about six weeks of age, the pups and their mother will rejoin the pack.

We encountered the pregnant female pictured above several nights on the Night Tour as she prepared her nest in a tree.

Coatis are omnivores and have a varied diet consisting of insects, frogs, lizards, small vertebrates, crabs, and fruit.

Their range spans from the southern United States, through Mexico, Central America and into western Colombia and Ecuador. Life expectancy for Coatis is about 14 years.

Crab-eating Raccoon - Procyon cancrivorus

There are two species of Raccoon in Costa Rica, but only the Crab-eating Raccoon makes its home in Drake Bay.

Both Raccoon species look very similar and are difficult to distinguish from a distance. The Crab-eating Raccoon is larger than the Northern Raccoon.

Crab-eating Raccoons differ from Northern Raccoons because the fur on their necks points towards the head, instead of towards the tail like the fur on rest of the animal's back.

Also, the bands on their tails tend to be orange instead of white, their feet are dark, and they tend not to have under fur.

The word Raccoon is derived from the North American indigenous word "arakun" meaning scratching hands.

They are very good climbers, but often forage on the ground. They feed on crabs, mollusks, fish, frogs, small vertebrates, insects, fruit and other food they may scavenge.

Raccoons are mainly solitary and nocturnal, but they are sometimes active during the day.  

Little is known about the natural history of Crab-eating Raccoons. We often observe this species on the tour and we have also captured their behavior on our camera traps. Crab-eating Raccoons often visit fruiting trees. They are typically solitary, but females can be seen with their kits from December to February and from April to June.

Raccoons use their incredibly sensitive hands to detect crustaceans underwater and under rocks. We have often capture them on our camera trap as they forage in our creek. You can observe this unique behavior in the videos below!

Western Andean Long-nosed Armadillo - Dasypus fenestratus

There are two species of armadillo in Drake Bay: the Northern Naked-tailed Armadillo (Cabassous centralis) and the Western Andean Long-nosed Armadillo (Dasypus fenestratus).  The latter is pictured here. The Mexican Long-nosed Armadillo (Dasypus mexicanus) is also present in northern Costa Rica.

Western Andean long-nosed Armadillos can be encountered in Drake Bay, although they are elusive.  They can be active at night or during the day and usually forage slowly, with their snout pressed right to the ground.  Their keen sense of smell aids them in detecting prey items living in the leaf litter or underground.  In the tropics, Armadillos feed mostly on ants and termites, as well as fallen fruit.

These animals have very poor eyesight and it is not uncommon for them to walk right into a bewildered hiker’s feet. When startled,  Western Andean Long-nosed Armadillos will often jump straight up into the air and rush to safety.

The reproductive cycle of  Western Andean Long-nosed Armadillos is nothing short of amazing.  After mating, females are able to control the start of pregnancy by delaying the implantation of the fertilized egg on the uterus wall.

Although this animal's gestation period only lasts about 2 months, female Armadillos have stunned researchers by giving birth up to 32 months after mating! When they do give birth, it is exclusively to same sex identical quadruplets.

Hoffmann's Two-toed Sloth - Choloepus hoffmanni

In Costa Rica's lowland rainforests Hoffmann's Two-toed Sloths, Choloepus hoffmanni, are not so common to see. These animals are mainly nocturnal and they forage high in the canopy. They are active about 8 hours per day.

Although they are active for shorter periods than Three-toed Sloths, Two-toed Sloths are more mobile. They change trees frequently and are rarely found in the same tree on consecutive days.

Two-toed Sloths feed mainly on leaves but they supplement their leafy diet with fruit, buds, flowers, insects, and even bird eggs and small vertebrates.

Two-toed Sloths have an incredibly long gestation period, about 11.5 months. Baby sloths cling to their mother during the first 6 months of their lives, never leaving her side.

Even after they are weaned, young sloths may remain close to their mother for up to two years.  They have been known to live up to 32 years in captivity.

A close inspection of the Two-toed Sloths in the two photographs featured here will reveal a distinctive green tint on the fur. Sloths have slits on each one of their hairs that serve as compartments where algae grows.

It has long been thought that the green tint afforded by the algae helps sloths better blend into their canopy habitat. This theory makes sense; after all having a green tint should help canopy dwelling sloths conceal themselves in the treetops.

Recently, though, researchers have proposed that perhaps the algae is providing sloths with an added benefit.

Scientists the sloths are feeding on the algae, which provides sloths with easily accessible and easily digestible energy. 

The moths, which can be observed on the photo on the left, play a role in this as well. It appears that the amount of algae growing on the fur is directly correlated to the number of moths living on the sloth. The algae thrives on the feces and decaying remains of the moths, so the bigger the moth population, the more the algae grows.

This leads researchers to think that the Sloth's peculiar habit of coming down to the ground to urinate and defecate could be linked to this chain.

When the sloth defecates on the ground, moths and beetles living on the sloth crawl down and lay their eggs on the feces. The larvae develop there and eventually fly back into the treetops as adults in search for another Sloth host.

The Sloths put themselves at considerable risk by travelling all the way down to the ground to defecate, but in doing so they provide these insects with a suitable place to lay their eggs and a great place for their larvae to develop.

The insects insure the propagation of the algae on the Sloth's fur and the algae provides the Sloth with an important nutritional supplement. The complicated relationship between these completely different creatures is so intertwined that Sloth Moths have evolved to live exclusively in the fur of Sloths and do not exist anywhere else in nature.

The Mexican Hairy Porcupine is one of the most elusive mammals in Drake Bay. So much so, that it is not listed as being on the Osa Peninsula in many of the guide books. It took us many years before we saw our first one and they are always a rare find around here.

They tend to be nocturnal and solitary and very little is known about their natural history.

Technically Porcupines are rodents and they are the only rodents in Costa Rica to have a prehensile tail. Porcupine's tails are different from any other new world mammal in that the gripping pad is located on top of the tail, rather than on the bottom.

When they grip with their tail it curls upward, as can be observed in the photograph featured here.

The Porcupine's quills are this animals most prominent and distinguishing feature.

Although Porcupines cannot throw their quills, the quills do provide Porcupines with protection from predators by breaking off very easily and lodging into a would  be predator's skin.

Each quill has a very sharp point and is covered with tiny backward pointing scales. This makes them very difficult to remove once they are lodged in the skin.

It is thought that the yellow quills also serve as aposematic coloration, warning colors, to deter predators. Also, when Porcupines are startled the quills stand vertically making them look much larger than they actually are.

Despite their spiny armor, felines feed on porcupines by flipping them onto their back where they lack quills.

Mexican Hairy Porcupines feed mainly on seeds, fruit, leaves, flowers and flower buds. They enjoy Ficus spp., Cecropia spp., and we often encounter them feeding on the fruit of Cojoba arborea.

Below is a video that we recorded during a Night Tour of a Mexican Hairy Porcupine feeding on Guava fruit.

Watson's Climbing Rat - Tylomys watsoni

Watson's Climbing Rat is a very large arboreal rat which is endemic to Costa Rica and Panama. It is known to live throughout Costa Rica, except in the dry northwestern part of the country, up to 3000 meters above sea level.

Although Watson's Climbing Rats have a widespread range, they are rare to see in Drake Bay. They are known to sometimes inhabit buidings in areas surrounded by forest.

Not much is know about this rodent's natural history, but they are known to feed on just about anything including plant material, lichen and bark. Apparently they have a strong preference for chocolate and soap!

Due to their arboreal habits and white-tipped tail, Watson's Climbing Rats are sometimes mistaken for opossums.

Tomes’ Spiny Rat - Proechimys semispinosus 

Tomes' Spiny Rats are nocturnal and are most often observed on dark nights. Studies have found that Tomes' Spiny Rats are just as active on moonlit nights, but they avoid open areas to evade predators.

They occupy an important place in the food chain, so they do indeed have a wide range of predators to worry about. A study carried out in Corcovado National Park revealed that one quarter of all puma scat and half of all ocelot scat examined contained the remains of Tomes' spiny rats. Another study from La Selva Biological Station revealed that Tomes' spiny rats are a favorite prey item of bushmasters (Lachesis stenophrys). Bushmasters are the world's longest pit vipers and are highly endangered throughout their range.

When confronted by a predator, Tomes' Spiny Rats have a built-in escape mechanism. Their long tail is designed with a weak point along the fifth vertebra which easily breaks when gripped by a predator. The tail does not grow back and as many as 25% of adult rats have no tail. I have known several people who have befriended large, tailless Tome's spiny rats with bananas, having confused them with baby agoutis!

During the day, Tomes' spiny rats sleep in underground burrows. They do not dig their own burrows, so they rely on natural cavities or burrows dug out by other animals. They may sleep on their own or with several other rats. On two separate occasions, I observed a Tomes' spiny rat crawl into a burrow already occupied by a smoky jungle frog (Leptodactylus savagei). With a maximum length of more than 14 centimeters, the smoky jungle frog is Costa Rica's largest frog species. They also spend their days in burrows, but they seem like unlikely roommates for a rat!

Tomes' spiny rats feed on fruit, seeds, fungi, and other vegetable matter. They are considered important seed dispersers. While foraging, Tome's spiny rats often collect food in their mouth then carry it to a safe place to eat.  

Central American Silky Anteater - Cyclopes dorsalis

With an average weight of 300 to 500 grams, silky anteaters are the smallest of all anteaters. They belong to the family Cyclopedidae which is made up entirely of silky anteaters. The silky anteater has long been considered a single species ranging from southern Mexico to Ecuador, Peru and Brazil in South America. A recent study published in 2018, however, suggests this species should be divided into 7 distinct species.

These tiny creatures move silently through the treetops in the darkness of the night. Silky anteaters feed almost exclusively on ants, using their enlarged front claws to tear into the nests. Like tamanduas, they ingest fleeing ants using their extraordinarily long tongue. The silky anteater's small size, however, prevents them from ripping into hard termite mounds. During the day, silky anteaters curl up into a tight ball and enter a deep sleep. Curling up tight helps them conserve energy by preventing heat dissipation. They also lower their metabolic rate and enter a state of torpor.

Much mythology surrounds these secretive and mystical creatures. Legends echo in the forests that silky anteaters supernaturally exist in multiple dimensions. Natives of Costa Rica's Talamanca region believe they only descend from the heavens to announce an impending death. Another widespread myth is that if captured, silky anteaters inexplicably disappear before daybreak. Silky anteaters are also sacred in the traditions of the Bri Bri tribe of southeastern Costa Rica. It is said these delicate creatures guide the souls of the dead into heaven.

Baird's Tapir - Tapirus bairdii

Baird's tapir is Costa Rica's largest land mammal. While they are not very tall, standing just under 120 centimeters, they are quite rotund. Baird’s tapir can weigh in at a hefty 150 to 400 kilograms. Their range extends from southeastern Mexico to northern Colombia and Ecuador. They are highly endangered throughout their range and it is estimated that only 5,500 individuals remain in the wild.

These gentle giants feed mostly on leaves, stems, fruit, and tree bark. Tapirs are shy, mostly solitary animals. They can be active day or night. They do not easily dissipate heat so they spend the hottest hours of the day in their preferred mud wallows. These are the best sites to see tapirs during dry season in Corcovado National Park. We have a mud wallow on our property which has been frequented by a breeding pair for several years.

Although studies on their natural history are scarce, male and female tapirs are thought to form lasting bonds and breed year-round. Their gestation is one of the longest of any mammal, lasting up to 400 days. Tapir calves have a spotted coat at birth, which enhances their camouflage. The streaked coloration disappears between 4 and 8 months after birth. Both parents play a role in raising their calf and young tapirs become independent in 1 to 2 years. They may live up to 25 years in the wild and up to 35 in captivity.

In recent years, we have seen an increase in Drake Bay's Baird's Tapir population. Here are a few videos of some of our Tapir encounters!

Enjoy our individual mammal pages by following the links located at top of the page on the right hand side!