The color of pacas is reddish-brown to darker brown on their backs, with several rows of spots down each side of a whitish color, and an underside that is a lighter brown. They don’t really have a tail, their legs are short and they have a large, blunt head. They are slow on land but are quite good swimmers. There are four digits on their front feet and 5 on their back feet. Their toes have claws that look like hooves. Their cheeks are enlarged and have resonating chambers that amplify sounds.
Pacas live in the neotropical parts of the Americas, from northeastern Mexico to Paraguay and northern Argentina, as far as southeastern Brazil. They live in a range of habitats, the typical one being tropical evergreen and subdeciduous forests. Pacas are found in disturbed habitats, and will often build their burrows near water, despite such sites being prone to flooding.
Pacas are mostly nocturnal. They can be quite aggressive within their home range towards other pacas of the same sex or towards other animals, such as agoutis. Pacas spend most of the day asleep in a hollow log or burrow. They occasionally travel in a small group that consists of a mated pair with their young. They either construct their own burrows, usually close by a water way, or they occupy burrows built by other animals. Burrows usually feature a couple of entrances for general use, several more for emergencies, and an internal area for sleeping. Pacas become frightened by unfamiliar stimuli. They are good swimmers and may enter the water if they feel threatened. Pacas will even mate in water.
Pacas feed mainly on fallen fruits, and will eat a wide range of plant material, such as seeds, leaves and tubers, either native or foreign species. They prefer foods high in energy, such as avocados or mangos, and may eat the fruit in its entirety, including the seeds, or discard certain parts.
Lowland pacas are monogamous, and a pair will mate for life. They usually produce only one or two young each year, with breeding taking place at any time of the year. They are sexually mature between 8 to 12 months. The gestation period lasts from 114 to 119 days and usually just one baby is produced. The young have fur when they are born and their eyes are open. They are born in a hole covered with twigs and leaves that is too small for predators and even the mother to enter. The mother invites her babies out with a low rolling vocalization. Mothers care for their young sometimes for only as long as 8 weeks, but sometimes for more than 6 months, with weaning taking place at about 3 months. The young follow their mother to learn or “imprint” on her behavior.
The predators of the paca include the cougar and the jaguar. Threats to the population include loss of habitat, fragmentation of the forest, hunting and domestic animal species. Hunting by farmers is on the increase because of the tendency of pacas to damage crops. They are hunted for their meat, considered as a delicacy.
According to The IUCN Red List Lowland Paca is widespread and locally common in the northern part of its range and scarce in the south of its distribution. But there are no estimates of population numbers for Lowland Paca. Currently this species is classifed as Least Concern (LC) on the IUCN Red List and its numbers today remain stable.
Pacas have an important effect on plant communities, the distribution and species variety of many plants being due to the actions of these animals, and for some fruiting species, pacas are essential for their regeneration. Indeed, the loss of pacas may mean the loss of certain tree species. Pacas eat the pods of a great number of tree species and thus effectively disperse those seeds throughout the forest, an important contribution to old-growth neotropical forests. These animals could also be regarded as ecosystem engineers, as they dig burrows that species other than themselves will use.