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Here’s a selection of the skulls that researchers find on Barro Colorado. First, take a look at each skull. Can you guess what the animal eats from the shape of its head and from its teeth? Scientists who have spent lots of time looking at skulls carefully can often tell the age of the animal, its state of health and sometimes its cause of death. For example, a bullet hole would mean that a poacher (it’s illegal to hunt in the Nature Monument) shot the animal. Tooth marks may mean that the animal was eaten by a predator. Fractures may lead one to believe that the animal fell from a tree.

Claudio Carrasco collects skulls to study animals on BCI


White tailed deer, “Venado Cola blanca”

Common names: White tailed deer. Venado Cola Blanca.

Scientific name: Odocoileus virginianus.

Size: Length (head and body): 113-226cm.

Length of tail: 13-14 cm.

Length of ears: 11-13 cm.

Weight: Males, approximately 50 kg, Females, approximately 30 kg.

Natural History: Active both during the day (diurnal) and during the night (nocturnal). White tailed deer are not common in mature tropical forest, preferring more open habitat. There is some dispute about whether or not they occur on Barro Colorado Island, although they are certainly present on the mainland within the Nature Monument.

Diet: Plants, flowers and fruit.

Distribution: North, Central and South America. From Southern Canada to Southern Peru.

Conservation: Common. Hunted for meat and sport. Some local populations are threatened due to extensive hunting.



Agouti paca, Paca

Common names: Agouti paca, Paca

Scientific name: Agouti paca

Size: Length (head and body): 61.6-77.5 cm

Length of tail: 1.2-3.2 cm

Length of ears: 4.3-5.6 cm

Weight: 5-13 kg.

Natural History: Active at night, generally solitary. May share a territory but forage (look for food) alone.
Diet: Fruit, especially hard fruit such as palm nuts, tender plants and roots.

Distribution: Central and South America, South West Mexico to Southern Brazil and Northern Paraguay.

Conservation: One of the most hunted animals in the forest, its meat is considered to be a delicacy. Hunted to extinction in some areas.


Three toed sloth, Perezoso de 3 garras

Common names: Three toed sloth, Perezoso de 3 garras

Scientific name: Bradypus variagatus

Size: Length (head and body): 40-75 cm

Length of tail: 3.8-9.0 cm

Length of ears: 0.8-2.2cm

Weight: 2.3-5.5 kg.

Natural History: Very slow moving. Lives in trees and vines.
Diet: Leaves.

Distribution: Central and South America. Honduras to Northern Argentina.

Conservation: Widely distributed species, common. Hunted for meat, but difficult to see, therefore not as affected by hunting as other game animals.


Coati Mundi, Gato solo, White nosed Coati

Common names: Coati Mundi, Gato Solo, White nosed Coati

Scientific name: Nasua narica

Size: Length (head and body): 46.3-69.0 cm

Length of tail: 49.0-62.0 cm

Length of ears: 3.4-4.2 cm

Weight: 4.5 kg

Natural History: Primarily active during the day (diurnal). Coatis often move in groups of 10 to 30 individuals.

These groups are formed by the females and the juveniles. The males are usually solitary and territorial, joining the group during the breeding season.

Diet: Omnivorous, they eat almost anything that they find in the forest: fruit, flowers, small animals (insects, snakes, worms). They often climb trees to reach fruit there.

Distribution: North, Central and South America. From Southern Texas and Arizona, throughout Central America, to the East Coast of Colombia, Ecuador and Peru.

Conservation: Not an endangered species. Scarce in some areas, but one of the species that is most frequently seen (often as a road kill) in areas near cities.


Collared Peccary, Zaino, Puerco de Monte

Common names: Collared Peccary, Zaino, Puerco de Monte

Scientific name: Tayassu tajacu

Size: Length (head and body): 80-98cm

Length of tail: 2.5-4.5 cm

Length of ears: 7.0-9.0 cm

Weight: 17-30 kg

Natural History: Mainly active during the day (diurnal). Peccaries travel in groups of 1-20 individuals, usually 6-9. Males may be solitary.

Peccaries move in lines along trails that they mark by digging up the soil at the base of trees, and by defecating and rubbing their scent glands on the bark of trees. They are very shy, which makes it difficult to get close to them. They may stampede when they detect the presence of people. In some areas, they are raised as pets. This is the only species of wild pig on Barro Colorado Island.

Diet: They are omnivorous, eating fruit, seeds, insects, larvae and small animals such as toads, rodents…etc.

Distribution: North, Central and South America. South Western United States to Northern Argentina.

Conservation: Intensively hunted for meat and for sport. Rare near human settlements, but locally common in protected areas.