Rodents of South America: The Agouti and the Paca
Agoutis and pacas are interesting, rabbit-sized rodents that live in the rainforests of Central and South America and forage on the forest floor. Agoutis weigh up to nine pounds. They're famous for being the only mammal that can open the hard fruit of the Brazil nut tree without a tool. They are sometimes kept as exotic pets. Pacas are stockier animals than agoutis and may weigh as much as twenty-six pounds.
At one time agoutis and pacas were thought to be closely related. The two animals do have a somewhat similar appearance. They each have a long head with small ears, a rump that is higher than the front part of their body, back legs that are longer than the front legs and a tiny, almost invisible tail. Today biologists know that there are important anatomical differences between the two animals and that they are not as closely related as was once thought.
There are eleven species of agouti, all belonging to the genus Dasyprocta. They have a widespread distribution in Central and South America. Their coat has a range of colors and may be black, brown, red-brown or orange-brown. The coat sometimes has a speckled or grizzled appearance due to the presence of multicolored hairs. The tail is short and hairless.
The agouti's hair is coarse and is longest at the back of the body over the rump. The hairs are covered with an oily substance that helps to waterproof the animal. This oil often gives the coat a glossy appearance. The animals are good swimmers and sometimes enter water to escape from danger.
An agouti has long legs. It moves on its toes rather than its whole feet and walks, trots, gallops and jumps. The animal can move very fast when necessary. It's also agile and can jump as high as six feet from a standing position.
When it feeds, an agouti often sits on its hind legs and holds its food with its front paws, as shown in the photo at the start of this article. Agoutis have five toes on each of their front feet and three on each of their back ones.
Agoutis spend the night in a hidden area such as a burrow or a tree hollow. During the day they search for food on the floor of the rainforest. They are often solitary animals, but some forage in small groups consisting of a mated pair and their offspring.
Agoutis sometimes venture on to the savanna to eat. Unfortunately, they may also enter agricultural fields and feed on crops meant for human use.
An agouti's diet consists chiefly of fruits, nuts, seeds, leaves, stems, roots and tubers. They sometimes follows monkeys around, waiting for them to drop fruit from the tree canopy. Agoutis have occasionally been observed eating insects, shellfish and eggs, making them omnivorous instead of strictly herbivorous.
"Brazil nuts" are actually the seeds of a fruit. Each seed has a hard coat, which is removed to extract the softer kernel inside. The kernel is the part that is eaten.
Agoutis and Brazil Nuts
Agoutis play an important role in the life of the Brazil nut tree (Bertholletia excelsa). The tree grows in rainforests and may reach a height of a hundred and sixty feet. It drops its ripe fruits on to the forest floor. Each fruit weighs as much as five pounds and is about the size of a grapefruit.
The agouti is the only mammal known to be able to break open the hard shell of the fruit. The rodents have strong, sharp teeth that can quickly crack the shell, allowing them to reach the seeds inside. The seeds are commonly known as "Brazil nuts" when they're harvested and sold to the public.
The agouti often extracts more nuts than it can eat. It buries these for future use but doesn't always find them again. Some of the nuts that the animal misses grow into new trees. The agouti therefore helps the Brazil nut tree to reproduce. It plays a similar role in the lives of some other plants of the rainforest.
An Adult Agouti in an Animal Sanctuary
Agoutis maintain a territory. They mark this territory by releasing a smelly secretion from their anal glands and by depositing smelly urine and feces in strategic places. Agoutis actively defend their territories. A common vocalization made during defense is a barking sound. The animal's rump hair may become erect during territorial disputes, which makes it look bigger and more threatening than it really is. It also stamps its hind feet when it's tense.
Agoutis are monogamous. A male and a female bond permanently and share a territory. They generally sleep and forage separately, however. In at least some species, the male sprays the female with urine during courtship. The urine excites the female and causes her to perform a "frenzy dance". After being sprayed one or more times she is usually ready to mate.
One to four babies are born after a gestation period of about three months. The babies are able to walk and run within an hour after their birth. Agoutis are long-lived animals and have survived for fifteen to twenty years in captivity.
A Baby Agouti in a Zoo
Agoutis as Pets
Agoutis are sometimes kept as exotic pets. They are usually shy and nervous in the wild but may be outgoing and friendly when bred in captivity. They are interesting animals to observe and are often considered to be cute. There is at least one drawback to having an agouti as a pet, though - he or she may produce an unpleasant smell. The agouti's anal glands release a smelly secretion that is used to communicate with other agoutis. The urine and feces may also be smelly, for the same reason.
A pet agouti should be bred in captivity and bought from a licensed breeder. This is important for two reasons. An animal born in captivity and used to humans from birth may be friendlier and more confident than one caught in the wild. In addition, breeding agoutis for the pet trade protects the wild populations. A prospective owner must find out if it's legal to own an agouti in their part of the world.
A Young Pet Agouti Playing
A New Pet in the Family
Before bringing a pet agouti into a family, a person should investigate the diet, housing and exercise requirements of the animal as well as any potential health problems. The recommended type and size of enclosure, the best location for the enclosure and essential items to put inside it should be explored. Like other rodents, agoutis are chewers, which should be kept in mind when building or buying an enclosure.
The owner needs to decide which areas the agouti is allowed to explore when it's outside its enclosure. This decision will likely be based on the animal's urination and defecation habits and on the extent to which it can be house trained. Potential dangers for the animal when it's out of its enclosure must also be considered. Harness training is essential for trips outside the home, since an agouti can move very fast and jump very high.
Alice the Agouti Enjoys a Meal
It should always be remembered that exotic pets aren't domesticated animals, even when they're bred in captivity. True domestication requires many generations of selective breeding. Agoutis need regular attention from their humans in order to maintain their confidence and friendliness around people and other animals. They are generally docile animals, but they do have strong teeth and jaws and could bite if frightened.
Another consideration is that it's unfair to purchase an agouti and then keep it alone in a small enclosure all the time. Like other pets, it needs interesting things to do. In captivity agoutis often have a long lifespan, so they are a long-term commitment.
A breeder or fellow agouti owners who are willing to offer advice after a pet is bought could be very helpful. It's important that the pet owner finds a vet with experience in treating agoutis.
There are two paca species: the lowland paca, or Cuniculus paca, and the mountain paca, or Cuniculus taczanowskii. As its name suggests, the mountain paca lives at higher elevations than the lowland species. The animals are generally more sedentary and slow-moving than agoutis. Pacas generally aren't kept as exotic pets, but the lowland species is present in some zoo collections. Wild pacas are caught for their meat, which is often considered to be a delicacy.
The lowland or spotted paca is widely distributed in Central and South America. It has a stockier body than the daintier agouti. The paca has a red brown to dark brown coat with several rows of white spots or stripes along its sides. Its undersurface is pale yellow. The head has a blunt snout and relatively large eyes. As in the agouti, the tail is barely visible. The legs are short. There are four toes on each of the front feet and five on each of the back ones.
The mountain paca is smaller than the lowland one. Its coat tends to be darker and its undercoat is denser. Its fur is dark brown to black and is spotted like that of its lowland relative. The animal is found from Venezuela to Bolivia. The lowland paca is not in trouble, but the mountain paca is classified as near threatened.
Pacas at the San Diego Zoo Safari Park
The cheek bones of a paca are enlarged. This feature helps to create resonating chambers that make the animal's sounds louder.
The Life of a Paca
Like agoutis, pacas are usually solitary animals, but they may occasionally travel in small groups made of a mated pair and their youngsters. They are often nocturnal but are sometimes seen in the early morning and late evening.
Pacas build their burrow near a river or stream. They sometimes occupy and modify a burrow made by another animal instead of making a new one, however. The paca's burrow has multiple entrances/exits. Emergency exits are usually disguised by a covering of leaves while the others are left open. Pacas are good swimmers and may enter the water when they feel threatened. Some pacas actually mate in water.
The paca is mainly herbivorous, eating fruit, seeds, leaves, shoots and roots, but it eats some insects as well. It generally doesn't hold its food in its front paws as an agouti does. A paca maintains a territory for feeding and breeding and defends this territory. When it's annoyed or threatened, the animal often produces a loud growl, which is amplified by its cheek chambers.
A Nocturnal Paca in the Wild
Lowland pacas are known to be monogamous. As in the agouti, the male paca urinates on the female to reinforce the bond between the two animals and to stimulate the female to mate.
The gestation period in the paca is around a hundred and eighteen days. Pacas generally have one baby per litter. The babies are born with fur and open eyes and can eat solid food by the end of their first day. The paca's lifespan seems to be about thirteen years in the wild.
A Lowland Paca in a Zoo
Categorizing Animal Species in Trouble
The IUCN, or International Union for Conservation of Nature, has established a "Red List of Threatened Species". This is a list of nine categories representing the population status of organisms.
Listed below are the Red List categories from the least serious condition to the most serious one. The seriousness of the first two categories can't be evaluated, however, since insufficient data is available.
- Not Evaluated (NE)
- Data Deficient (DD)
- Least Concern (LC)
- Near Threatened (NT)
- Vulnerable (VU)
- Endangered (EN)
- Critically Endangered (CR)
- Extinct in the Wild (EW)
- Extinct (EX)
The Brazilian Agouti
The State of Agouti and Paca Populations
The eleven agouti and two paca species are classified in the Least Concern or Data Deficient categories in the IUCN Red List, with the exception of these five species.
- Orinoco agouti: Near Threatened
- Coiban agouti: Vulnerable
- Ruatan Island agouti: Endangered
- Mexican agouti: Critically Endangered
- Mountain paca: Near Threatened
Major agouti and paca predators include ocelots, jaguars and snakes, especially boa constrictors. Like many other species in trouble, however, some agouti and paca populations are experiencing problems due to human activities.
Loss of habitat and hunting can put severe pressure on a species, as in the case of the agouti and paca species listed above. Habitat loss as humans clear land for their own purpose is a serious problem for wildlife. Like pacas, agoutis are caught for their meat, and both animals are sometimes killed as agricultural pests. Careful planning and action are needed to protect agoutis and pacas and to ensure that all the species survive.
© 2013 Linda Crampton