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Paca

The paca is a genus of large, ground-dwelling rodents (family Cuniculidae) native to Central and South America, characterized by their robust, pig-like bodies, spotted brown fur, short tails, and nocturnal lifestyle.^[1] There are two extant species in the genus Cuniculus: the widespread lowland paca (C. paca), found from Mexico to northern Argentina, and the rarer mountain paca (C. taczanowskii), restricted to the Andean highlands of Colombia, Ecuador, Peru, and Venezuela.^[1] Both species measure 60–80 cm in length, weigh 6–12 kg (with males typically larger), and feature distinctive white spots or stripes on their sides that fade with age, aiding in camouflage within forested habitats.^[2] Pacas inhabit a range of tropical and subtropical environments, including lowland rainforests, cloud forests, and montane areas up to 3,000 meters elevation, often near rivers or streams where they construct extensive burrow systems for shelter and escape from predators.^[2] They are primarily herbivorous, with a diet dominated by fallen fruits (such as those from palms and laurels), seeds, roots, and occasional leaves or invertebrates, contributing significantly to forest regeneration through seed dispersal via their feces.^[2] Behaviorally, pacas are mostly solitary or live in monogamous pairs, exhibiting territorial aggression toward same-sex intruders and strong swimming abilities that allow them to cross water barriers; they are active at night, using their keen sense of smell to forage while remaining vigilant against predators like jaguars, ocelots, and harpy eagles.^[2] Reproduction occurs year-round in stable habitats, with females giving birth to 1–2 precocial young after a gestation of about 115 days, reaching sexual maturity at 8–12 months; wild lifespan averages 12–15 years, though hunting pressure reduces this in many regions.^[2] Culturally, pacas are valued as a bushmeat source across their range, leading to sustainable management efforts in some areas, while the lowland paca is listed as Least Concern by the IUCN due to its adaptability and broad distribution, in contrast to the mountain paca's Near Threatened status from habitat fragmentation.

Taxonomy

Classification

The paca belongs to the order Rodentia, the suborder Hystricomorpha, and the family Cuniculidae, which comprises large, ground-dwelling rodents native to Central and South America.^[3] This placement reflects its hystricognathous jaw articulation and other morphological adaptations typical of advanced rodents.^[1] As part of the Caviomorpha clade, pacas share evolutionary ties with other South American rodents such as agoutis, though they form a distinct lineage.^[4] The genus Cuniculus is the only genus within Cuniculidae and includes the recognized paca species. Historically, pacas were classified under the genus Agouti (as Agouti paca), but this was revised in 1998 by a ruling of the International Commission on Zoological Nomenclature, which prioritized Cuniculus based on priority and type species designation to avoid taxonomic confusion with the unrelated agoutis in family Dasyproctidae.^[2] This separation was further supported by differences in cranial and dental morphology that distinguish Cuniculus from Agouti.^[5] Classification of pacas relies on key diagnostic traits, including a dental formula of I \frac{1}{1}, C \frac{0}{0}, P \frac{1}{1}, M \frac{3}{3} = 20, characterized by high-crowned (hypsodont) cheek teeth with prismatic enamel folds that form isolated islands upon wear.^[4] Cranially, pacas exhibit a robust, heavily built skull with a narrow infraorbital foramen functioning as a mere canal, wide zygomatic arches for powerful jaw musculature, and enlarged cheek pouches indicated by swollen temporal regions.^[6] These features aid in distinguishing Cuniculidae from related families and underscore adaptations for herbivory and burrowing.^[2] The common name "paca" originates from the Tupi-Guarani indigenous languages of South America, specifically the Tupi term paka, which denotes the animal and also conveys meanings like "awake" or "alert," reflecting its vigilant nocturnal behavior.^[7] This etymology highlights the deep cultural significance of the paca among indigenous peoples long before European scientific naming.^[8]

Recognized Species

The genus Cuniculus comprises two recognized species of pacas, large rodents native to the Neotropics, distinguished primarily by their geographic ranges and subtle morphological adaptations to different habitats. The lowland paca (C. paca) is characterized by a light to dark brown coat with four distinct rows of white spots along each side, providing camouflage in forested environments. This species inhabits lowland tropical and subtropical forests from east-central Mexico southward through Central America to northern Argentina, preferring areas near water sources such as rivers and swamps. Its IUCN Red List status is Least Concern, reflecting its widespread distribution and relatively stable populations despite local hunting pressures.^[2] In contrast, the mountain paca (C. taczanowskii) exhibits a reddish-brown coat with four rows of white spots that are more pronounced than in the lowland species, along with softer and denser fur suited to cooler, higher-altitude conditions. It is endemic to montane forests in the Andes, ranging from northwestern Venezuela through Colombia, Ecuador, and Peru to central Bolivia, typically at elevations between 2,000 and 4,000 meters.^[9]^[5]^[10] This adaptation to montane environments includes a slightly smaller body size and differences in skull morphology, such as larger auditory bullae relative to cranial length. The mountain paca is classified as Near Threatened by the IUCN due to habitat loss from deforestation and agriculture, with populations declining in some areas.^[10] Historically, both species were classified under the genus Agouti—with the lowland paca as Agouti paca (originally Mus paca Linnaeus, 1766) and the mountain paca as Agouti taczanowskii (originally Coelogenys taczanowskii Stolzmann, 1885)—until taxonomic revisions in the late 20th century elevated Cuniculus to distinguish the family Cuniculidae from true agoutis. Debates on species validity have centered on whether C. taczanowskii represents a distinct species or a highland subspecies of C. paca, but molecular and morphological evidence supports their separation, though the validity of several subspecies within C. paca (such as C. p. nelsoni and C. p. paca) remains unresolved pending further genetic studies.^[5]^[11]^[12]

Evolutionary History

Origins and Fossil Record

The origins of pacas trace back to the broader radiation of caviomorph rodents in South America, which began with the arrival of hystricognath ancestors likely via transatlantic rafting from Africa during the Eocene, around 40 million years ago. The fossil record of early caviomorphs is first documented in the late Oligocene Deseadan South American Land Mammal Age (approximately 28–23 million years ago), with key sites such as the Salla Formation in Bolivia yielding primitive representatives of the superfamily Cavioidea, the clade encompassing modern pacas. These early fossils, including genera like Chubutomys and Asteromys, exhibit foundational traits such as ever-growing incisors and hypsodont molars adapted for herbivory, marking the initial diversification of terrestrial rodent lineages in isolation on the continent.^[13] The family Cuniculidae, to which pacas belong, has an exceedingly poor fossil record, with no definitive remains known from the Miocene or earlier periods, reflecting a "ghost lineage" inferred from phylogenetic analyses of related cavioids. The earliest confirmed cuniculid fossils appear in the Pleistocene, dating to approximately 1.8 million to 10,000 years ago, primarily from karst cave systems in eastern Brazil. Notable among these is the extinct species Cuniculus rugiceps, described from multiple sites and characterized by a larger body size (estimated at 12–15 kg) and more robust dentition than extant pacas, suggesting adaptations for processing tougher vegetation in late Quaternary environments.^[14] Key fossil localities for Pleistocene cuniculids include the Lagoa Santa karst complex in Minas Gerais, Brazil, where over 100 specimens of C. rugiceps have been recovered from sites like Cuvieri Cave, providing the most complete skeletal evidence for the genus. These remains, often found in association with other megafauna, date to around 30,000 years ago and reveal morphological features such as expanded zygomatic arches and strong mandibular rami, indicative of enhanced chewing efficiency derived from Miocene cavioid ancestors. Middle Miocene assemblages from the La Venta Formation in Colombia (13.5–11.8 million years ago) document diverse cavioids like Prodolichotis and Simplimus, illustrating the broader evolutionary context of hypsodonty and cranial reinforcement in the lineage leading to Cuniculidae, though no direct paca relatives are present.^[15]^[16] Evolutionary adaptations in ancestral caviomorphs foundational to pacas include the progressive development of burrowing-specialized postcranial elements, such as robust humeri and femora for digging, and herbivorous dental specializations like prismatic enamel for abrasive plant matter, evident in Oligo-Miocene fossils across South America. Molecular clock estimates place the divergence of Cuniculidae from other cavioids in the early Miocene, around 22–25 million years ago, aligning with the temporal framework of Cavioidea radiation during the Laventan Age.^[17]^[18] Post-Great American Biotic Interchange (approximately 3 million years ago), the paca lineage underwent limited diversification, remaining endemic to South America with fossil evidence showing morphological continuity into the Holocene; Pleistocene forms like C. rugiceps represent the primary extinct branch, while modern Cuniculus species exhibit stasis in size and skeletal proportions. Phylogenetic analyses position Cuniculidae as the sister group to Dasyproctidae within Cavioidea, underscoring their deep roots in Neotropical rodent evolution.^[19]

Phylogenetic Relationships

The family Cuniculidae, which includes the pacas, is placed within the superfamily Caviomorpha of the infraorder Hystricognathi based on cladistic analyses integrating molecular and morphological data. This positioning reflects the South American radiation of hystricognath rodents, where Cuniculidae belongs to the superfamily Cavioidea alongside other families adapted to diverse Neotropical habitats.^[20] Molecular phylogenies, particularly those using multi-locus datasets, identify the closest relatives of Cuniculidae as the Dasyproctidae (agoutis), with the two families forming a clade sister to the Caviidae (guinea pigs and capybaras).^[20] This relationship is supported by analyses of cytochrome b gene sequences, which highlight shared evolutionary history within Cavioidea. Chinchillidae, representing the superfamily Chinchilloidea, occupies a more distant position within Caviomorpha, diverging earlier from the Cavioidea lineage.^[20] Divergence estimates derived from relaxed molecular clock models indicate that the split between Cuniculidae and Dasyproctidae occurred approximately 20–25 million years ago during the early Miocene. These timelines align with the broader diversification of Cavioidea, following the initial radiation of Caviomorpha around 35 million years ago.^[20] Comparative morphology further corroborates these molecular findings, particularly through shared features of the hystricomorphous zygomasseteric system, characterized by an enlarged infraorbital foramen allowing passage of the medial masseter muscle, which distinguishes Hystricognathi from other rodents and supports the infraordinal placement of Cuniculidae.^[21]

Physical Description

Morphology

The lowland paca (Cuniculus paca) possesses a robust, hystricomorph rodent body plan featuring an elongated torso, a very short and nearly hairless tail, and sturdy limbs suited for burrowing and terrestrial locomotion. The forelimbs are equipped with four functional digits ending in thick, blunt, hoof-like claws, while the hindlimbs have five digits, with the first and fifth reduced in size, providing stability and propulsion during movement. This structure supports their primarily ground-dwelling habits, including the excavation of dens in forested environments.^[2]^[22] The head of the paca is large and blunt, with prominent features adapted for sensory perception and vocalization in low-light conditions. It includes large, dark eyes positioned for enhanced nocturnal vision, short rounded ears, and long, stiff whiskers (vibrissae) that aid in navigation through dense undergrowth. The skull is notably robust, with a broad, laterally expanded zygomatic arch and concavities in the maxillary bones forming a resonating chamber for producing distinctive rumbling calls; additionally, the presence of small cheek pouches facilitates vocal communication. The mouth houses ever-growing incisors typical of rodents, which are used for gnawing vegetation and can be clicked or snapped as a defensive display.^[2]^[22]^[23] The paca's coat consists of coarse, grizzled fur lacking a dense underfur, typically dark brown to blackish on the dorsal surface and yellowish-white on the ventral side, accented by four to five rows of white or yellowish spots along the flanks that provide camouflage in dappled forest light. These spotting patterns vary slightly among subspecies, with more pronounced or numerous spots in some populations, such as C. p. paca. The overall pelage is relatively thin and bristle-like. The mountain paca (C. taczanowskii) has longer and darker fur than the lowland paca.^[2]^[22]^[23] Skeletal adaptations in pacas emphasize durability and functionality for their ecological niche, including a heavily built cranium that supports powerful jaw musculature for processing tough plant material. The cheek teeth are high-crowned (hypsodont) and rooted, enabling efficient grinding of fibrous foods, while the dental formula is I 1/1, C 0/0, P 1/1, M 3/3, totaling 20 teeth. Limb bones, such as the humerus and femur, exhibit robust proportions that facilitate digging and evading predators through swimming or quick bursts on land.^[2]^[6]

Size and Variations

Adult lowland pacas exhibit a body length ranging from 60 to 80 cm, with males typically measuring 65 to 82 cm and females 60 to 70 cm.^[2] Their weight generally falls between 6 and 12 kg, though some individuals can reach up to 14 kg.^[2] These measurements reflect the robust, stocky build characteristic of the species, adapted for a terrestrial lifestyle in forested environments. The mountain paca has a similar size range. Sexual dimorphism in pacas is subtle, primarily manifested in body size, where males are slightly larger and heavier than females on average.^[2] This difference is estimated at about 15% in mass for males compared to females in some populations.^[24] Juveniles grow rapidly, attaining approximately 4 kg by three months and 6 kg by six months of age.^[2] They reach adult size within 1 to 2 years, coinciding closely with the onset of sexual maturity around 8 to 12 months.^[2]

Behavior

Activity Patterns

The lowland paca (Cuniculus paca) exhibits primarily nocturnal activity patterns, with the majority of its movements and behaviors occurring during nighttime hours to avoid predation and diurnal heat. Studies using camera traps have recorded approximately 79% of paca activity as nocturnal, with peaks typically between dusk and dawn.^[25] While predominantly active at night, pacas also display crepuscular tendencies, showing increased movement around twilight periods and occasionally at dawn, which may facilitate foraging while minimizing exposure to daylight predators. Pacas are adept burrowers, constructing extensive underground tunnel systems that serve as primary shelters during the day. These burrows often reach depths of up to 2 meters and feature multiple exit holes for escape routes, along with internal chambers for resting; individuals typically use several such cavities within their home range. Daytime is spent sleeping in these protected spaces, emerging only under cover of darkness to reduce vulnerability. Activity levels in pacas are influenced by seasonal variations, particularly rainfall and temperature, with patterns adjusting to environmental conditions across wet and dry periods. In dry seasons, pacas maintain their nocturnal rhythm but may exhibit slightly reduced overall activity, potentially as an adaptation to conserve water and energy amid limited resources. When faced with disturbances such as approaching predators or human activity, pacas respond with rapid flight, seeking refuge in their burrows or nearby water bodies, where their strong swimming abilities aid evasion. The lowland paca exhibits a predominantly solitary or paired social structure, typically living as monogamous pairs that share a home range while maintaining separate burrows during the day; the mountain paca (C. taczanowskii) is presumed to have similar behavior based on limited data.^[2] Adult pairs occupy territories ranging from 1.5 to 3 hectares, with males actively defending these areas against intruders of the same sex or other species, such as agoutis, through displays of aggression to maintain exclusivity.^[26] Unlike more gregarious rodents like agoutis, which may form small family groups, paca group sizes rarely exceed pairs, reflecting their territorial intolerance and limited social tolerance.^[27] Communication among pacas primarily occurs through vocalizations and chemical signals to convey territory boundaries and emotional states. They produce a repertoire of calls, including roars, groans, and cries, which serve functions such as contact maintenance during separation or threat signaling, with cry calls notably used by offspring to elicit maternal responses.^[28] Scent marking is achieved via urine, feces, and secretions from anal glands, allowing individuals to advertise occupancy and deter rivals within their home range.^[4] Social interactions are characterized by minimal aggression between mated pairs, which cooperate in territory defense, though intense confrontations arise during territorial disputes or intrusions by conspecifics.^[27] Post-birth, strong mother-offspring bonds form, with females providing care to highly mobile young in secure nests, fostering independence while using vocal cues for reunification after separations.^[29] Nocturnal activity patterns concentrate these encounters in the evening and night, when pairs forage together or defend shared spaces.^[2]

Diet and Feeding

Food Sources

Pacas (Cuniculus paca) maintain a primarily herbivorous diet, consisting mainly of fallen fruits, supplemented by seeds, leaves, and tubers. This frugivorous feeding strategy allows them to exploit a variety of native and introduced plant materials, with preferences for high-energy options such as mango (Mangifera indica), avocado (Persea americana), and papaya (Carica papaya).^[2]^[30] Dietary composition varies seasonally, with higher intake of fruits during wet seasons when availability peaks, and a shift toward tubers, seeds, and leaves during dry periods of fruit scarcity, often from November to March. This adaptability helps pacas rely on stored fat reserves during lean times.^[2]^[31]^[32] The nutritional profile of their diet is characterized by high fiber content from fibrous fruits, leaves, and tubers, alongside low protein levels typical of tropical fruits and seeds, which pacas supplement through cecotrophy to obtain microbial protein. Occasional consumption of fungi or invertebrates is reported but not central to their herbivorous habits.^[33]^[34] Key plant families in their diet include Arecaceae (palms), which provide important fruit sources, as well as contributions from Anacardiaceae, Lauraceae, and Moraceae through species like those mentioned above; pacas consume fruits from at least eleven families overall.^[12]^[2]

Foraging Behavior

Pacas primarily engage in ground foraging, searching for food on the forest floor in close proximity to their burrows and den sites, which limits their exposure to predators and allows rapid escape when necessary. This behavior is centered within small home ranges that shift according to seasonal fruit availability, typically expanding around late August when fruiting peaks.^[2] As largely nocturnal animals, pacas employ strategies to minimize predation risk during foraging, emerging only under cover of darkness and preferring the dimmest possible conditions, such as dense understory or sheltered spots. They possess adaptations for low-light activity, including a tapetum lucidum reflective layer in their eyes and specialized retinal ganglion cells that enhance night vision, enabling efficient navigation and food detection without relying on bright illumination. Additionally, pacas avoid open areas during nights with high moonlight intensity, further reducing visibility to visual predators like ocelots and harpy eagles.^[2]^[35] Pacas demonstrate selective feeding efficiency by prioritizing nutrient-dense, high-energy food items, such as ripe fruits from species like mango (Mangifera indica), papaya (Carica papaya), and avocado (Persea americana), while avoiding less nutritious options like certain flowering plants or palms. They consume these items with targeted precision, extracting the most valuable pulp and seeds to maximize nutritional intake relative to effort expended. Unlike related rodents such as agoutis, pacas do not cache or bury food for later use but instead rely on substantial fat reserves accumulated during periods of abundance to endure food scarcity. Their foraging targets primarily fallen fruits and seeds, aligning with their role as opportunistic frugivores.^[2]^[12]

Reproduction

Mating and Breeding

Pacas exhibit a mating system that may involve polygyny, with males maintaining larger home ranges that overlap extensively with those of multiple females, allowing them to court several partners, though they are also observed in monogamous pairs.^[36]^[2] This spatial arrangement facilitates male tolerance toward females and potential promiscuity, with observed interactions including close proximity and suggestive vocalizations during presumed mating events.^[36] Breeding in pacas occurs year-round across their tropical range, enabled by consistent food availability, but reproductive activity peaks during the rainy season when rainfall and fruiting events increase pregnancy rates.^[37] Environmental drivers such as elevated river levels and peak forest fruit production during wet periods correlate with higher lactation and weaning success, optimizing offspring survival.^[37] The estrous cycle in females averages 32.5 days, with courtship initiated by brief naso-nasal contacts between males and receptive females.^[38] During these rituals, males may display dominance through urination or spraying, while females respond with growls or aggressive biting if unreceptive; vocalizations, including grunts and whistles, accompany pair formation and mating attempts.^[38]^[36] Gestation lasts 114–119 days (approximately 115 days in the wild), after which females typically give birth to a single precocial young, though twins occur rarely; inter-birth interval is about 190 days, and females reach sexual maturity at 8–12 months.^[2] This reproductive strategy supports low but steady population growth in stable habitats.

Offspring Development

Paca offspring are typically born in litters of one, with twins occurring rarely.^[2] The gestation period lasts approximately 115 days in the wild (up to 149 days in captivity), resulting in precocial young that are born fully furred, with eyes open and capable of mobility within hours of birth.^[2] At birth, neonates weigh around 600–750 grams (average ~700 g), representing about 8–10% of adult body weight, and exhibit well-developed skeletal and external features that enable immediate independence from intensive parental supervision.^[2] Parental care is primarily provided by the female, who nurses the young for approximately three months, though the duration of direct care can range from eight weeks to over six months depending on environmental factors.^[2] Males offer minimal protection, as pairs maintain independent burrows and show limited involvement in rearing.^[40] The mother uses low rolling vocalizations to encourage the young to emerge from the birth burrow, which is constructed small enough to deter predators.^[41] Growth is rapid postnatally; young reach about 4 kg by three months and 6 kg by six months, with weaning occurring between six and twelve weeks of age.^[2]^[42] Independence follows weaning, typically between two and six months, though some juveniles may remain near the mother for up to twelve months before fully dispersing.^[2]^[41]^[24] Neonatal survival is relatively high due to the precocial strategy that reduces dependence on extended care and minimizes exposure to predators through early burrow use and mobility.^[2] Despite threats from predators such as felids and canids, the low production of young combined with these adaptations supports effective population maintenance in natural habitats.^[4]

Distribution and Habitat

Geographic Range

Pacus, belonging to the genus Cuniculus, are native to Central and South America, with their distribution spanning from eastern Mexico southward to northern Argentina.^[11] This range encompasses all countries of Central America, as well as northern and central portions of South America, including Colombia, Venezuela, the Guianas, Ecuador, Peru, Brazil, Bolivia, Paraguay, Uruguay, and Trinidad and Tobago.^[11] The genus is represented by two recognized species, each occupying primarily distinct elevational zones within this broad Neotropical expanse, with some overlap possible in mid-elevations.^[43] The lowland paca (Cuniculus paca) predominates in lowland tropical and subtropical regions, occurring from sea level to elevations of about 2,300 m.^[2] Its distribution covers the entirety of Central America and extends into the Amazon basin and adjacent areas of South America.^[11] In contrast, the mountain paca (C. taczanowskii) is restricted to higher-altitude Andean forests, ranging from northwestern Venezuela through Colombia, Ecuador, Peru, and into Bolivia, typically between 1,800 and 3,000 m.^[44] These species-specific ranges reflect adaptations to varying topographic and climatic conditions across the continent. Fossil records document the presence of C. paca in Mexico dating back to the late Pleistocene, indicating that the species' northern extent has been established for at least this period, with subsequent expansion southward facilitated by continuous land connections in Central America.^[5] Introduced populations of C. paca are rare outside the native range, with small, non-established groups reported in Cuba and Algeria, likely resulting from escapes or releases from captivity.^[2] These occurrences do not form viable wild populations and represent minimal expansion beyond the natural Neotropical boundaries.^[2]

Habitat Preferences

Pacas primarily inhabit tropical forest ecosystems, including rainforests and secondary growth areas, where they favor environments with dense vegetation and proximity to water bodies. These rodents are commonly found in lowland rainforests, such as those in the Amazon Basin and Central America, as well as in more seasonal tropical subdeciduous forests. Their preference for such habitats is driven by the availability of cover and escape routes, with studies indicating higher densities in mature forests compared to open areas.^[45]^[46] Microhabitat requirements emphasize locations near streams and rivers, often within 100 meters of water sources, which provide quick aquatic escape options from predators. Pacas seek out dense understory layers for concealment and foraging, avoiding open or flooded zones that limit mobility. This selection for riparian zones with thick vegetation supports their crepuscular lifestyle, enhancing survival in predator-rich environments. In the Lacandon Rainforest, for instance, cavity availability near water significantly influences local abundance.^[46]^[35] The altitudinal range of pacas extends from sea level up to approximately 3,000 meters in montane forests, allowing occupancy across diverse elevations within their Neotropical distribution. They occur in both lowland and mid-elevation forests, including cloud forests at higher altitudes, though densities decrease in extreme montane conditions. This broad elevational tolerance reflects adaptability to varying forest structures while maintaining core preferences for humid, forested settings.^[45]^[2] Pacas demonstrate tolerance for disturbed habitats, such as secondary growth and agricultural plantations adjacent to natural forests, where they can persist at lower densities. This adaptability enables them to utilize edge habitats and human-modified landscapes like croplands or agroforests, provided there is sufficient cover and water access. Research in Chiapas, Mexico, shows pacas using such areas as sink populations, relying on nearby source habitats for recruitment.^[46]^[2]

Human Interactions

Utilization by Humans

Pacus, primarily the lowland paca (Cuniculus paca), are extensively hunted for their meat, which serves as a vital protein source in the diets of indigenous and rural communities across Central and South America, particularly in the Amazon basin where they represent one of the most frequently targeted species. The meat is prized for its tender texture and rich flavor, contributing significantly to subsistence nutrition in areas with limited access to domesticated livestock, and is low-fat and high in protein.^[47]^[48]^[49] The mountain paca (C. taczanowskii) is also hunted for its meat in Andean highland communities, though less commonly due to its restricted range and lower population densities.^[9] In regions such as Mexico, where the animal is known as tepezcuintle, pacas hold notable cultural significance among Mayan and mestizo populations, appearing in traditional folklore and cuisine as a symbol of forest bounty and featured in communal feasts that reinforce social bonds. This cultural role extends to other parts of the range, where the meat is prepared in stews or roasted dishes, underscoring its integration into local culinary traditions beyond mere sustenance.^[50]^[51] The use of paca pelts is limited, primarily confined to small-scale local applications for simple crafts or hides in indigenous communities, with no evidence of widespread commercial exploitation or farming for fur products. Efforts toward domestication have focused on experimental breeding programs aimed at sustainable meat production, such as those conducted in Panama, where captive rearing has demonstrated potential for controlled yields while adapting the species to enclosure-based husbandry without commercializing other byproducts.^[52]^[53]

Conservation Status

The lowland paca (Cuniculus paca) is classified as Least Concern on the IUCN Red List due to its extensive distribution across tropical Central and South America and presumed large population sizes, which buffer against widespread extinction risks.^[45] However, local populations face vulnerability, with extirpations reported in fragmented southern ranges, particularly in parts of Central America where habitat conversion has isolated subpopulations.^[2] The mountain paca (C. taczanowskii) is classified as Near Threatened due to habitat fragmentation and loss in the Andean highlands, combined with hunting pressure, leading to population declines estimated at less than 30% over ten years.^[54] Primary threats to pacas include deforestation driven by agricultural expansion and logging, which reduces suitable forested habitats, and overhunting for bushmeat, with harvest rates in some Amazonian areas reaching up to 0.4 individuals per square kilometer annually. Roadkill exacerbates these pressures in fragmented landscapes, where infrastructure development increases mortality; studies in Brazilian Cerrado protected areas and Central American highways document pacas among frequently roadkilled species, contributing to localized declines.^[2]^[55]^[56] Conservation efforts emphasize protected areas, such as Amazonian reserves including Jaú National Park in Brazil and the Lacandon Rainforest in Mexico, where pacas maintain stable densities of 6–90 individuals per square kilometer due to reduced human access. Hunting regulations, including Brazil's 1967 federal law (Law No. 5.197) prohibiting commercial exploitation of wildlife while allowing limited subsistence hunting in extractive reserves, help sustain populations through community-based management plans that rotate hunting zones.^[2]^[57] Population trends remain stable in core Amazonian ranges, supported by occurrence in extensive protected networks, but show declines at range edges in Central America due to intensified fragmentation. Reforestation efforts in areas like the Atlantic Forest in Brazil have supported paca populations alongside habitat rehabilitation.^[58]

References

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Mammal Species of the World - Browse: paca
HOME --> CLASS MAMMALIA --> ORDER RODENTIA --> SUBORDER HYSTRICOMORPHA --> INFRAORDER HYSTRICOGNATHI --> FAMILY Cuniculidae --> GENUS Cuniculus SPECIES ...<|control11|><|separator|>
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OrderRodentiarodents. Rodentia: information (1) Rodentia: pictures (789) Rodentia: specimens (847) Rodentia: sounds (2). FamilyCuniculidaepacas. Cuniculidae ...
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Pacas are very large, up to around 12 kg in males. Females are somewhat smaller. They have chunky bodies, short, stout legs, hind limbs that are longer than the ...Physical Description · Reproduction · Predation
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Dec 10, 1992 · Agouti paca is nocturnal, although sometimes it is active in the early morning and late afternoon (Smythe, 1970). The paca walks along fixed ...<|control11|><|separator|>
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Paca, or PaCa, refers to a member of the family Cuniculidae, which includes large, semi-aquatic rodents native to Central and South America, known for their ...
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Word History ; Etymology. Portuguese, from Tupi páka ; First Known Use. 1657, in the meaning defined above ; Time Traveler. The first known use of paca was in 1657.
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Mountain pacas are listed as "low risk" by the IUCN. In some areas they are rare because of hunting pressures, in other areas populations are high, up to 90 per ...Missing: taxonomy | Show results with:taxonomy
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Fig. 4. Fossils of the extinct paca Cuniculus rugiceps (Lund, 1837)...
Here we provide a taxonomic review of extinct cuniculids, and discuss the taxonomic, biogeographic, taphonomic and chronologic aspects of new remains.
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[17]
(PDF) A brief history of caviomoph rodents as told by the fossil record
The first stages of the evolution of cavioids are more obscure because they are recognized through the relatively derived Deseadan species of Cavioidea s.s. ...
[18]
Reconciling Fossils, Ghost Lineages, and Relaxed Molecular Clocks
The fossil record of Cuniculidae is extremely poor and only starts in the Pleistocene [119], [120]. Cavioidea s.s., in contrast, has an extremely rich fossil ...
[19]
(PDF) Evolution of the caviomorph rodents: a complete phylogeny ...
Cuniculidae + Dasyproctidae are recovered as sister to Caviidae (including Hydrochoerus). Abrocomidae (including Cuscomys) is sister to the remaining ...
[20]
EOCENE RADIATION AND PHYLOGENY OF THE RODENTS
The criteria that have most gen- erally been used for superfamilial arrang- ing of the rodents are: the structure of the zygoma and infraorbital foramen and of ...
[21]
None
### Physical Description of the Lowland Paca (Cuniculus paca)
[22]
Lowland Paca | Mexican Terrestrial Life.org
They have large heads, swollen cheeks, short ears, large dark eyes, and long whiskers. Straight and bristlelike hairs lie flat in their coarse, shiny coat.
[23]
Cuniculus paca - Plazi TreatmentBank
May 30, 2022 · Taxonomy. Mus paca Linnaeus, 1766 ,. “Brasilia [= Brazil], Guiana ... species. Breeding. The Lowland Paca has a low reproductive rate ...<|control11|><|separator|>
[24]
Home range and habitat use by pacas in a montane tropical forest in ...
Paca home ranges average 2.26 ha (SD = 1.76) at our study site. Although our sample size is very small, our results suggest that females have slightly smaller ...ABSTRACT · RESUMEN · Text · ACKNOWLEDGEMENTS
[25]
Spatial and temporal interactions of free-ranging pacas (Cuniculus ...
Jan 19, 2018 · Results. Paca home range sizes appeared to achieve an asymptote at ~ 125 locations based on area accumulation curves (AACs) (Fig. 1).
[26]
Vocal complexity and sociality in spotted paca (Cuniculus paca)
Phylogenetic relationships, ecological correlates, and molecular evolution within the Cavioidea (Mammalia, Rodentia). Mol Biol Evol. 2002; 19: 263–277. pmid ...
[27]
Vocal complexity and sociality in spotted paca (Cuniculus paca) - PMC
Jan 24, 2018 · A behavioral response from a conspecific, immediately after the call was released, could lead to freezing and hiding in burrows.
[28]
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0190961
[29]
https://pmc.ncbi.nlm.nih.gov/articles/PMC5783385/
[30]
https://doi.org/10.1007/s00114-002-0391-5
[31]
Direct and indirect caecotrophy behaviour in paca (Cuniculus paca)
Jul 13, 2018 · As tropical fruits have low protein concentrations, caecotrophy could be an important microbial protein source in frugivorous rodents such as ...
[32]
Nutrition of Six Selected Neo-Tropical Mammals in Trinidad and ...
The paca was described as a strict vegetarian that consumed plants, herbs, nuts, fruits, seeds, tubers and roots, at night. In captivity, they ate corn ...
[33]
Ranging behavior and habitat selection of pacas (Cuniculus paca ...
Nov 10, 2016 · The few studies that have attempted to quantify home range sizes of pacas indicate small ranges within high-density populations in primary ...
[34]
https://pmc.ncbi.nlm.nih.gov/articles/PMC6024322/
[35]
https://academic.oup.com/jmammal/article/98/2/542/2454680
[36]
https://doi.org/10.1007/s13364-017-0350-0
[37]
[PDF] MAMMALIAN SPECIES so, . . . - Agouti paca.
Dec 10, 1992 · Cuniculus Hollister, 1913, is a junior homonym of Cuniculus Wagler, 1830:21 (a microtine rodent). Stictomys Thomas, 1924:238. Type species ...Missing: synonyms debates
[38]
[PDF] Embryonic and fetal morphology in the lowland paca (Cuniculus paca)
Aug 3, 2017 · low natural predation rate, with a low production of young and high neonatal survival rate in nature. Although the paca is possibly the most ...<|control11|><|separator|>
[39]
Lowland Paca - Los Angeles Zoo and Botanical Gardens
Pacas are related to guinea pigs, capybaras, and agoutis. The lowland paca (also known as the spotted paca) is found at lower elevations than their cousins, ...Missing: biology | Show results with:biology
[40]
Paca - Facts, Diet, Habitat & Pictures on Animalia.bio
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.
[41]
Lowland paca (Cuniculus paca) longevity, ageing, and life history
Classification (HAGRID: 02940). Taxonomy: Kingdom: Animalia Phylum: Chordata Class: Mammalia (Taxon entry) Order: Rodentia Family: Cuniculidae Genus: Cuniculus
[42]
Cuniculus taczanowskii • Mountain Paca
Una nueva especie de Cuniculus (Rodentia: Cuniculidae) de la cordillera Central de Colombia. Revista de la Asociación Colombiana de Ciencias Biológicas, 22, 122 ...
[43]
[PDF] Taxonomic, biogeographic, and taphonomic reassessment of a ...
Jun 21, 2016 · The taxonomy of extinct species of Cuniculus (Caviomorpha, Rodentia, Mammalia) is confusing and poorly studied. Here we provide a taxonomic ...<|control11|><|separator|>
[44]
The IUCN Red List of Threatened Species
### Summary of Habitat & Ecology for Cuniculus paca
[45]
(PDF) Abundance, density and habitat use of lowland paca ...
Aug 6, 2025 · Agouti paca. Mammalian Species 404:1–7. Potts, g., J. Coulson, And i. deAns. 1980. Population dynamics. and breeding success of the shag ...
[46]
Hunters and hunting across indigenous and colonist communities at ...
Aug 10, 2018 · Lowland pacas (Cuniculus paca) were the most frequently hunted prey, followed by red brocket deer (Mazama americana) and primates. While hunting ...
[47]
Subsistence hunting of Cuniculus pacain the middle of the Solimões ...
Pacas are one of the most hunted animals in the Amazon due to the renowned flavour of their meat (Deutsch and Puglia, 1990). In the Amanã Sustainable ...
[48]
Proximate composition of wild meats present in traditional food ...
The protein levels were considerable in all species analyzed, the average protein content found was 22.27, 23.47, and 22.31 g/100g of meat in mammals, birds, ...
[49]
Cultural significance of wild mammals in mayan and mestizo ...
May 7, 2015 · Five species are recognized by more than 50% of the population (tepezcuintle, puerco de monte, venado cola blanca, armadillo and jaguar –lowland ...
[50]
Abundance, density and habitat use of lowland paca (Cuniculus ...
In this study, the effect of relevant variables (availability of food and cavities, competition, predation, and hunting pressure) on the relative abundance and ...Missing: intraspecific | Show results with:intraspecific
[51]
The paca (Cuniculus paca) as a domestic source of protein for the ...
A brief description of what is known of the behaviour of wild pacas is given, and these characteristics are discussed in relationship to domesticability. Those ...
[52]
[PDF] Captive Breeding of wild species - Amazon AWS
Paca (Agouti = Cuniculus paca). Smythe (1991) was involved in a trial of meat production from. Paca farms in Panama over a period of at least seven years. The.
[53]
Assessing the population density of the spotted paca, Cuniculus ...
Nov 22, 2018 · The spotted paca, Cuniculus paca (Linnaeus, 1766), is a Neotropical, opportunistic, frugivorous caviomorph rodent, that inhabits primarily ...
[54]
mammal roadkills in the threaten lowland Atlantic Forest in ... - SciELO
The objective of this study was to evaluate the impact of roadkill on wild mammals on RJ-122, a highway that crosses the threaten lowland Atlantic Forest in ...
[55]
Turning the game around for conservation: using traditional hunting ...
Jan 1, 2016 · This study shows that the use of a hunting technique to capture paca is an efficient and safe procedure that may be applied at different sites ...
[56]
COP26: Brazil's REGUA as a model of ecosystem restoration
Nov 9, 2021 · Heavily hunted herbivores including Capybara (Hydrochoerus hydrochaeris) and Lowland Paca (Cuniculus paca) moved in, and carnivores such as ...
[57]
Mammal species biodiversity in a Costa Rican protected tropical ...
Apr 18, 2024 · This study considers changes in mammal species biodiversity over time in a protected and reforested tropical rainforest environment.