A paca is a member of the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''Cuniculus'' of ground-dwelling, herbivorous
rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
s in
South
South is one of the cardinal directions or Points of the compass, compass points. The direction is the opposite of north and is perpendicular to both east and west.
Etymology
The word ''south'' comes from Old English ''sūþ'', from earlier Pro ...
and
Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...
. It is the only genus in the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Cuniculidae. Pacas are large rodents with dots and stripes on their sides, short ears, and barely visible tails. Pacas are eaten by people in Belize, where they are known as "gibnut" and, having been served to
Queen Elizabeth II
Elizabeth II (Elizabeth Alexandra Mary; 21 April 1926 – 8 September 2022) was Queen of the United Kingdom and other Commonwealth realms from 6 February 1952 until Death and state funeral of Elizabeth II, her death in 2022. She was queen ...
, "the royal rat". In the Amazon basin they are known as "majás".
The
Smithsonian Tropical Research Institute
The Smithsonian Tropical Research Institute (STRI, es, Instituto Smithsonian de Investigaciones Tropicales) is located in Panama and is the only bureau of the Smithsonian Institution based outside of the United States. It is dedicated to understa ...
in Panama has studied the possibilities of developing the paca as a viable high-priced food supply for the tropics.
Evolutionary background
Pacas originated in South America and are one of the few mammal species that successfully emigrated to North America after the
Great American Interchange
The Great American Biotic Interchange (commonly abbreviated as GABI), also known as the Great American Interchange and the Great American Faunal Interchange, was an important late Cenozoic paleozoogeographic biotic interchange event in which lan ...
. They were formerly grouped with the
agoutis
The agouti (, ) or common agouti is any of several rodent species of the genus ''Dasyprocta''. They are native to Middle America, northern and central South America, and the southern Lesser Antilles. Some species have also been introduced else ...
in the family
Dasyproctidae
Dasyproctidae is a family of large South American rodents, comprising the agoutis and acouchis. Their fur is a reddish or dark colour above, with a paler underside. They are herbivore, herbivorous, often feeding on ripe fruit that falls from tree ...
, subfamily
Agoutinae
Dasyproctidae is a family of large South American rodents, comprising the agoutis and acouchis. Their fur is a reddish or dark colour above, with a paler underside. They are herbivore, herbivorous, often feeding on ripe fruit that falls from tree ...
, but were given full family status because they differ in the number of toes, the shape of the skull, and coat patterning.
Description
left, Paca
Pacas are in length, excluding the short tail, weigh , and are the sixth-largest rodents in the world. Similar to
guinea pig
The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy (), is a species of rodent belonging to the genus ''Cavia'' in the family Caviidae. Breeders tend to use the word ''cavy'' to describe the ani ...
s, they have square heads, small ears, sides patterned with spots and stripes, and virtually invisible tails.
With large hind limbs, small fore limbs, and cone-shaped bodies, pacas are similar in appearance to the deer-like, ungulate
chevrotain
Chevrotains, or mouse-deer, are small even-toed ungulates that make up the family Tragulidae, the only extant members of the infraorder Tragulina. The 10 extant species are placed in three genera, but several species also are known only ...
s, and like them have four to seven horizontal lines of blotches and stripes along their flanks. They have a heavy and robust appearance, though their legs are long and relatively tiny. Their small ears are set high on their heads. They have four toes on their fore feet and five on their hind feet (of which two are short and hardly touch the ground) and they have stout nails that resemble small hooves. In young pacas, the skin is covered with horny scales about in diameter; perhaps these scales have a protective function against smaller predators. There is virtually no difference between sexes. They can live up to 13 years in the wild.
Behavior
Pacas inhabit
rainforest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...
s,
cloud forest
A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud c ...
s, and sometimes more open habitats. They are great swimmers and prefer to be near water. They dive when threatened and can stay submerged up to 15 minutes. They can also jump up to and freeze for up to 45 minutes. They normally move along well-established paths and will create new paths when old ones are disturbed.
They are normally passive in daytime and forage in the morning and afternoon, but can be strictly nocturnal in areas with many predators. They live in burrows up to deep, normally with two entrances covered with leaves to hide the burrow and to serve as an early warning system. Burrows are often near water, but always above the seasonal flood line. Predators except humans include
jaguar
The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus '' Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the th ...
,
puma
Puma or PUMA may refer to:
Animals
* ''Puma'' (genus), a genus in the family Felidae
** Puma (species) or cougar, a large cat
Businesses and organisations
* Puma (brand), a multinational shoe and sportswear company
* Puma Energy, a mid- and d ...
,
ocelot
The ocelot (''Leopardus pardalis'') is a medium-sized spotted wild cat that reaches at the shoulders and weighs between on average. It was first described by Carl Linnaeus in 1758. Two subspecies are recognized. It is native to the southwes ...
,
margay
The margay (''Leopardus wiedii'') is a small wild cat native to Central and South America. A solitary and nocturnal cat, it lives mainly in primary evergreen and deciduous forest.
Until the 1990s, margays were hunted illegally for the wildlife ...
,
jaguarundi
The jaguarundi (''Herpailurus yagouaroundi'') is a wild cat native to the Americas. Its range extends from central Argentina in the south to northern Mexico, through Central and South America east of the Andes. The jaguarundi is a medium-sized ...
,
bush dog
The bush dog (''Speothos venaticus'') is a canine found in Central and South America. In spite of its extensive range, it is very rare in most areas except in Suriname, Guyana and Peru; it was first identified by Peter Wilhelm Lund from fossils ...
,
boa constrictor
The boa constrictor (scientific name also ''Boa constrictor''), also called the red-tailed boa, is a species of large, non-venomous, heavy-bodied snake that is frequently kept and bred in captivity. The boa constrictor is a member of the family B ...
, and
caiman
A caiman (also cayman as a variant spelling) is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family, the other being alligators. Caimans inhabit Mexico, Central and South America fro ...
.
Pacas have resonating chambers in their cheeks and their growling noise, at about 1 kHz, is surprisingly loud for their size. Aside from making noises, territories are marked with urine. Population density can reach up to 70 adults per , and pacas often constitute some 20% of the biomass of terrestrial mammals.
Feeding
![HumedoTepezc 02](https://upload.wikimedia.org/wikipedia/commons/0/03/HumedoTepezc_02.jpg)
In the wild, pacas eat fruits from
understory
In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abov ...
trees and fallen fruits from taller trees, but may also eat leaves, buds, flowers, fungi, and insects. They play a vital role in seed dispersal, and, with seasonal adaptations, their home ranges are often centered on a group of fruit trees. Pacas normally do not use their fore-paws to manipulate fruits (as do agoutis), instead using their powerful jaw muscles to break open hard-shelled fruits. Unlike agoutis, pacas can store fat, and so are less dependent on the caching of seeds. Competition from agoutis is avoided by a slight variation in activity cycles and food preferences. Like rabbits, pacas are
coprophagous
Coprophagia () or coprophagy () is the consumption of feces. The word is derived from the grc, κόπρος , "feces" and , "to eat". Coprophagy refers to many kinds of feces-eating, including eating feces of other species (heterospecifics), of ...
and absorb protein and carbohydrates from specially produced moist fecal pellets. Before allowing their young to suckle, mothers lick them to stimulate them to defecate and urinate, and then lick the resulting product, both to feed herself and to prevent the odour from attracting predators.
Reproduction
Gestation lasts between 114 and 119 days with about 190 days between births. Pacas are
precocial
In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...
, the young are born with fur and open eyes. Normally, mothers give birth to one young, but she can give birth up to three times per year if conditions allow. More than one birth per year results in lactation periods overlapping pregnancies.
Weaning
Weaning is the process of gradually introducing an infant human or another mammal to what will be its adult diet while withdrawing the supply of its mother's milk.
The process takes place only in mammals, as only mammals produce milk. The infan ...
begins after six weeks, but the young start to follow their mothers early and can do so for up to a year.
Sexual maturity is reached after 6–12 months, when females weigh about and males . Pacas usually mate in water. As the male approaches the female, she starts to hop enthusiastically, more so if he sprays her with urine. Pacas have altered the common rodent strategy — safety in numbers — and mind their offspring carefully. At at birth, the young are born in holes too small for both predators and the mother to enter, which are then covered with leaves and twigs. To invite the young out of the hole, the mother uses a low rolling vocalization. Suckling usually lasts for 90 days, after which the young weighs .
Distribution and habitat
The lowland paca is found from southern Mexico to northern Argentina. They primarily live in rainforests near streams, but can also be found in a wide variety of habitats, including mangrove swamps,
gallery forest
A gallery forest is one formed as a corridor along rivers or wetlands, projecting into landscapes that are otherwise only sparsely treed such as savannas, grasslands, or deserts. The gallery forest maintains a more temperate microclimate above th ...
s near water currents, and even in public parks. They have been observed up to above sea level.
The smaller mountain paca lives in the northern
Andes
The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...
and the
Páramo
Páramo () can refer to a variety of alpine tundra ecosystems located in the Andes Mountain Range, South America. Some ecologists describe the páramo broadly as "all high, tropical, montane vegetation above the continuous timberline". A narrower ...
grasslands, with a peak occurrence between above sea level.
Species
The mountain paca has longer and darker fur than the lowland paca. Observations indicate mountain pacas are found between above sea level.
*
Lowland paca
The lowland paca (''Cuniculus paca''), also known as the spotted paca, is a large rodent found in tropical and sub-tropical America, from east-central Mexico to northern Argentina, and has been introduced to Cuba and Algeria.
The animal is cal ...
, ''Cuniculus paca'' (
Agouti paca
The lowland paca (''Cuniculus paca''), also known as the spotted paca, is a large rodent found in tropical and sub-tropical America, from east-central Mexico to northern Argentina, and has been introduced to Cuba and Algeria.
The animal is calle ...
)
*
Mountain paca
The mountain paca (''Cuniculus taczanowskii'') is a small burrow-dwelling rodent whose habitats are high altitude South American forests. Pacas are nocturnal, sedentary, and solitary animals with territorial tendencies. It eats mostly fruits and ...
, ''Cuniculus taczanowskii''
* ''
Cuniculus hernandezi
The mountain paca (''Cuniculus taczanowskii'') is a small burrow-dwelling rodent whose habitats are high altitude South American forests. Pacas are nocturnal, sedentary, and solitary animals with territorial tendencies. It eats mostly fruits and ...
'' (a recent and disputed ''
nomen nudum
In taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published with an adequate descr ...
'')
Citations
General sources
*
*
*
*
*
*
External links
Gibnutsat Crooked Tree Wildlife Sanctuary
{{Taxonbar, from=Q202697
Hystricognath rodents
Mammals of Guyana
Coprophagous animals
Rodents of Central America
Taxa named by Mathurin Jacques Brisson