Cavies and maras

(Caviidae)

Class Mammalia

Order Rodentia

Suborder Hystricognathi

Family Caviidae

Thumbnail description
Range from short, stocky body form to rabbit-like with long slender legs and nails that are hoof-like; either clawed digits or nails; scampering or cursorial locomotion; pelage relatively short and gray to agouti dorsally and paler on ventral surface

Size
Head and body length 5.9–29.5 in (150–750 mm); tailless or tail length 0.9–1.3 in (24–35 mm); weight 7 oz to 35.2 lb (200 g to 16 kg)

Number of genera, species
6 genera; 16 species

Habitat
Low elevations up to elevations of 16,400 ft (5,000 m), semiarid thorn shrub, grassland and savanna, riparian forest and forest edge, rocky outcrops, steppe vegetation with sparse shrubs, and cultivated areas

Conservation status
No species listed by the IUCN

Distribution
Broadly distributed throughout South America

Evolution and systematics

The family Caviidae first appears in the fossil record during the middle Miocene of South America. The family is a member of the monophyletic Cavioidea, a superfamily containing three additional families, Agoutidae, Dasyproctidae, and Hydrochaeridae. Traditionally, the Caviidae has been subdivided into two subfamilies, with Galea, Cavia, Microcavia, and Kerodon placed in the subfamily Caviinae and Dolichotis and Pediolagus in the subfamily Dolichotinae. Based on morphological studies, capybaras of the family Hydrochaeridae are considered to be the closest relative to the Caviidae. A molecular phylogenetic study by Rowe and Honeycutt in 2002 suggests considerable modification of the current phylogenetic arrangements of both genera in the Caviidae and relationships among families in the superfamily Cavioidea. Cavids appear most closely related to the family Agoutidae, and rather than being a separate family, these molecular data suggest that the Hydrochaeridae is related to Kerodon, and these two lineages are most closely aligned with Dolichotis and Pediolagus, members of the subfamily Dolichotinae. Therefore, the Caviinae is confined to three genera, Cavia, Microcavia, and Galea, with the first two genera being more closely related. Assuming that Kerodon was a member of the Caviinae, Lacher in 1981 suggested that similarities in the social system seen in Kerodon and members of the Dolichotinae provided evidence of convergence in response to similar habitat constraints and the distribution of resources. The molecular phylogenetic arrangement has implications for understanding the evolution of life history traits, especially those related to mating systems and resource availability. The placement of the rock cavy, Kerodon and Hydrochaeris, as members of the Dolichotinae suggests that shared ancestry, rather than similarities in ecological constraints, best explains the evolution of social behavior in these rodents. In this regard, both the rock cavy and the capybara have a harem-based polygynous breeding system and are habitat specialists. If the molecular data are correct, then the ancestor to capybaras, rock cavies, maras, and salt-desert cavies may have been highly social. This complex social system may very well be associated with patchily distributed resources.

The genus Cavia is the most diverse in terms of species and overall geographic distribution. Although as many as eight species have been recognized, Wilson and Reeder in 1993 listed five species. The other Caviinae genera, Microcavia and Galea, each contain three species, whereas Kerodon

is represented by one species with a restricted distribution. Although Pediolagus salinicola was considered a species within the genus Dolichotis, recent treatments based on morphology and nucleotide sequences suggest that it represents a genus separate from the currently recognized Dolichotis patagonum.

Physical characteristics

Members of the family are stout bodied with large heads and short pelage. Like many mammals that feed on plant materials, cavids have high-crowned jaw teeth that are continuously growing. Dorsal coloration varies from yellow, gray, olive, and agouti, with ventral pelage color being white or lighter than upper parts. Size and basic body plan ranges from small, tailless, short-legged cavies (Cavia, Microcavia, and Galea) with body lengths 5.9–15.7 in (150–400 mm) and weights of 7.0–21.1 oz (200–600 g) to large-bodied, rabbit-like salt-desert cavies and maras (Dolichotis and Pediolagus) with short tails 0.9–1.3 in (24–35 mm) and long, slender limbs, and larger body sizes 17.7–29.5 in (450–750 mm) and weights of 2.2–35.2 lb (1–16 kg). Dolichotis is considerably larger than Pediolagus. Unlike the small, scampering cavies, salt-desert cavies and maras are highly specialized for cursorial or fast-running locomotion displaying digit reduction and hoof-like nails. Cavies have clawed digits with less reduction in number (four on front and three on rear). The rock cavy, Kerodon rupestris, is the ecological-equivalent of rock hyraxes in Africa. Its padded feet and nail-like digits make it highly adapted for climbing rocks and trees.

Distribution

Cavia is the most broadly distributed genus, occurring throughout most of South America from Colombia to Argentina, whereas rock cavies are confined to rocky outcrops in restricted areas of Brazil. Other genera and species are common in parts of southern Peru, Bolivia, Paraguay, Chile, and Argentina.

Habitat

Habitat utilization varies with species that are generalists occurring in areas containing an even distribution of resources and more specialized species adapted to arid conditions and sparsely distributed resources. Maras and salt-desert cavies are more common in temperate steppe habitats characterized by

scattered shrubs and grasslands. Habitat preferences of cavies are more varied, represented by thorn bush, forested areas near water, grasslands, and cultivated lands. Compared to guinea pigs, the cuis lives in more arid habitats, and the rock cavy is specialized for patchily distributed rocky outcrops. Most species prefer lower elevations and none occur above 16,400 ft (5,000 m).

Behavior

The cuis, mountain cavy, and mara excavate burrows. All species have diverse repertoires of vocalizations related to

alarm calls, aggressive interactions (especially among males), courtship, and play. Most species exhibit scent-marking behaviors, especially rubbing of the ano-genital region. Males may urinate on females during courtship (enurination). All species are diurnal, with highest activity peaks in mornings and afternoons. Species within the family are colonial and vary in mating system. According to Rood's classic study in 1972, which detailed the behavior of cavies, species within these three genera are colonial, and males have a linear dominance hierarchy that maintained by aggressive interactions. In 1995 Kunkele and Hoeck observed communal suckling in the cuis,

Galea musteloides. During courtship, cuis males perform hops, and individuals within a colony socially groom. Vocalizations are varied squeaks, "churrs," screeches, whistles, and chattering of teeth. Male cavies have very distinctive courtship, with a "rhumba" display, best described for guinea pigs. The mating system of guinea pigs (genus Cavia) and mountain cavies (genus Microcavia) is polygynous with a dominant male breeding several females. The cui is promiscuous, and there is evidence of multiple paternities for single litters of the cuis. Sachser and others in 1999 indicated that these contrasting mating systems in the cuis and guinea pig are related to testes size in males, with male cuis having larger testes sizes than male guinea pigs.

Rock cavies display resource defense polygyny, whereby males protect rock piles and attract groups of females. Both males and females have linear dominance hierarchies. Maras have a male-dominant hierarchy and display monogamy. The studies of Taber and Macdonald revealed the formation of pair bonds lasting several breeding seasons with the female representing a mobile "territory" defended by the male. During the breeding season, the offspring of multiple pairs occupy a communal den, unlike the cuis, whose mothers nurse only their offspring.

Feeding ecology and diet

Many species like the rock cavy are generalist herbivores, feeding on a variety of leaves, seeds, fruits, and flowers. Others feed more on grasses, leaves, and cacti. Some species, like rock cavies and mountain cavies, climb while foraging. Most non-climbers feed more on grasses and low growing vegetation.

Reproductive biology

Cavids display a range of mating systems including hierarchical promiscuity, polygyny, and monogamy. Young are born precocial and mature sexually at an early age. Smaller cavies, including the rock cavy, range in gestation period from 50–70 days, are polyestrous (producing multiple litters per year), and are capable of postpartum estrus. Litter size can be as high as seven, but in most small species litter size is one to three. Maras and salt-desert cavies are more seasonal in breeding patterns and produce small litters of one to two offspring, which are extremely precocial, due to convergence with small antelopes. In general, the smaller species have larger reproductive outputs.

Conservation status

No species are currently listed by IUCN.

Significance to humans

The guinea pig has been domesticated since 1000 b.c. and, in some areas of Ecuador, Peru, and Bolivia, is raised for food. Ancient Incas apparently used the guinea pig in religious sacrifices. Smaller cavies are considered agricultural pests in some regions, and other species can impact grazing areas. Larger cavies are hunted for food and skins.

Species accounts

List of Species

Mountain cavy

Microcavia australis

subfamily

Caviinae

taxonomy

Microcavia australis (I. Geoffroy and d'Orbigny, 1833), Patagonia, near lower part of Rio Negro, Argentina.

other common names

English: Desert cavy; Spanish: Cuis chico.

physical characteristics

Head and body length averages 8.2 in (210 mm), weight 12.3 oz (350 g). Males are somewhat larger than females. Dorsal pelage is agouti mixed with yellow and brown, and ventral side paler. Hair around the eye appears as a ring. Individuals are tailless, have clawed digits.

distribution

Occurs primarily in Argentina and portions of southern Chile.

habitat

Occurs at lower elevations than related species in arid and semiarid habitats; a desert specialist. In portions of its range, it occurs in more mesic, forested habitats. Groups live in burrow systems.

behavior

Diurnal, live in burrows, and form colonies. Colonies sizes of up to 38 individuals in one burrow system have been observed. Social structure is based on a linear male dominance hierarchy, with aggressive interactions among males. Colony stability is habitat dependent. Three types of vocalizations include a low pitched "tsit" for alarm, series of squeaks during mating and social grooming, and a high-pitched shriek emitted when afraid. During breeding and play, hops and other body postures are observed.

feeding ecology and diet

Varied herbivorous diet consisting of leaves, seeds, grass, and other types of vegetation; browse and climb.

reproductive biology

Males are promiscuous and breed with multiple females. Multiple litters averaging three offspring per litter are produced each year, and the average gestation period is 54 days. Young are precocial.

conservation status

Common, and not threatened or endangered throughout its range.

significance to humans

Adapts well to humans and is considered an agricultural pest in some areas. Sometimes used as food by humans.

Guinea pig

Cavia aperea

subfamily

Caviinae

taxonomy

Cavia aperea Erxleben, 1777, Pernambuco, Brazil.

other common names

English: Cavy; Spanish: Quiso, cui, cori, cobaye.

physical characteristics

Head and body length average 13.7 oz (350 mm), tailless, and weight 17.6–52.9 oz (500–1,500 g). Legs are short, large head, digits clawed and slightly reduced (three on hind foot and four on front). Color of dorsal pelage is olive brown with paler coloration underneath. The domestic species, Cavia porcellus, is larger, more robust, and varied in color. Some have short hair, while others have long, straight, or curly hair. Considerable research on genetics of coat color and characteristics of the fur has been performed on domestic varieties of guinea pigs.

distribution

Occurs broadly in South America from Colombia through Brazil and Argentina. Most widely distributed genus in South America.

habitat

Takes shelter in brush and piles of rocks. Habitat varied, consisting of savanna in both subtropical and tropical regions, grasslands, and edges of forests. Have a preference for grassy habitat.

behavior

Displays both diurnal and nocturnal activity. Guinea pigs form colonies with a linear dominance hierarchy for both males and females. Males are less tolerant of each other in the wild species relative to the domestic species. The species is highly vocal and has calls for warning, courtship, and aggressive interactions; these calls range from "clucks" to "whets."

feeding ecology and diet

Generally feed throughout the day on grasses, and have been observed feeding in groups. Feeding areas normally close to cover.

reproductive biology

The mating system is polygynous and involves males mating with more than one female. Gestation averages 62 days for wild species and is shorter in the domestic guinea pig. Guinea pigs breed continuously and experience postpartum estrus. Minimum age for first reproduction in females is 30 days. Young are precocial and weaned at an early age. Offspring have been observed eating solid food two to three days after birth. The social organization of guinea pig populations changes with increases in number of individuals. There is a stronger linear dominance hierarchy when populations are low, and when populations are larger, individuals form subgroups of a few males and females. In the small subgroups dominant males appear to be highly successful at monopolizing breeding of females in estrus.

conservation status

Common, not threatened.

significance to humans

Still used for food today; presumably, the Incas used guinea pigs for food and in religious ceremonies. The domestic species has been used as an animal model for studying human diseases and toxins harmful to man. Other medical uses have involved the development of serums and vaccines as well as psychological experiments. Early studies of animal population genetics focused on variation of the guinea pig's coat color. Guinea pigs are kept as pets and become very interactive.

Cui

Galea musteloides

subfamily

Caviinae

taxonomy

Galea musteloides Meyen, 1832, Paso de Tacna, Peru.

other common names

English: Yellow-toothed cavy.

physical characteristics

Short legs and large head. Head and body length average 6.8 in (175 mm), tailless, and weighs 10.5–21 oz (300–600 g). Females tend to be heavier than males. Upper parts are agouti and ventral surface is a pale white. Digits show little reduction and are clawed.

distribution

Found in southern Peru, Bolivia, Argentina, and the northern portion of Chile.

habitat

Habitat is varied and includes savanna and thorn shrubs, grasslands, and scrub forests. Populations can be found at several elevations up to 16,404 ft (5,000 m).

behavior

The cui is diurnal, colonial, and forms a male linear dominance hierarchy that is established and maintained by aggression in the form of threats and attacks; the level of aggression is dependent upon both age and sex, and females are generally dominant over males of the same age. In captivity, females have been observed to communally nurse young. Display a variety of vocalizations associated with sexual encounters, aggression, and warning.

feeding ecology and diet

Herbivorous and feeds on grasses, forbs, and other vegetation. Individuals observed feeding throughout the day.

reproductive biology

Breeding is promiscuous, and females may breed with more than one male. Evidence of multiple paternity has been confirmed. Presumably, low success of single male mating is the result of promiscuity on the part of the female. Breeding appears to be continuous with females capable of producing up to seven litters per year. Apparently, males can induce ovulation in females by copulation. Gestation is 53–54 days. In comparison to other cavids, testes size of males is large.

conservation status

Common, not threatened.

significance to humans

Potential agricultural pest.

Rock cavy

Kerodon rupestris

subfamily

Caviinae

taxonomy

Kerodon rupestris (Wied-Neuwied, 1820), Rio Belmonte, Bahia, Brazil.

other common names

Spanish: Moco.

physical characteristics

Little information exists on measurements of head and body lengths for either males or females. Individuals weigh 31.7–35.2 oz (900–1,000 g). Dorsal coloration is gray with some black, ventral surface is brown with yellow, and the throat is white. Relative to other small cavies, the overall body is longer, and the face has a muzzle similar to that of a dog. Rather than clawed, the digits have nails, except for one grooming claw, and the feet are padded for movement on rocky surfaces. Rock cavies have long, slender legs.

distribution

Occurs only in eastern Brazil from the state of Piaui to the northern part of Minas Gerais.

habitat

The species is considered a habitat specialist, preferring arid areas with rocky outcrops.

behavior

Excellent rock climbers. Individuals are active later in the day, colonial with males defending optimal piles of rocks. Alarm calls consist of a whistle, and during estrus, males and females perform elaborate courtship behavior. They frequently exhibit scent marking, and social grooming is common.

feeding ecology and diet

Herbivorous and prefers leaves of plants. Spend considerable time foraging in trees and have been observed sitting upright during feeding.

reproductive biology

A harem-based mating system; both males and females form linear dominance hierarchies. Females undergo postpartum estrus, gestation averages 75 days, and several litters are produced each year, with the size between one to two young per litter. Young are born precocial and capable of foraging for solid food.

conservation status

Although not listed by IUCN, habitat specialization and limited distribution make this species potentially vulnerable. Two reserves have been established in Brazil.

significance to humans

Sometimes used for food.

Mara

Dolichotis patagonum

subfamily

Dolichotinae

taxonomy

Dolichotis patagonum (Zimmermann, 1780), Puerto Deseado, Santa Cruz Province, Argentina.

other common names

English: Patagonian hare, Patagonian cavy.

physical characteristics

Largest of the cavids with head and body length average 28.3 in (720 mm), tail short averaging 1.4 in (35 mm), and weight averages 26.4 lb (12 kg). Males tend to be larger than females. Highly adapted for fast running, appearing rabbit-like. Large body and head, hind legs are long and claws appear hoof-like; the foot posture is digitigrade. The muzzle is broad and rostrum short. Dorsal pelage is agouti in color, the rump black, and the under parts are cream colored. Rump area with a distinctive patch and chin appears orange colored.

distribution

Resides in central and southern Argentina, and is subdivided into two subspecies, one occurring in the more northern provinces of Catamarca, La Rioja, and Cordoba, and the other found in the provinces of Buenos Aires, southern Cordoba, San Luis, and Mendoza.

habitat

Preference for temperate steppe habitats in more arid area characterized by coarser grasses and sparsely distributed shrubs, flats containing creosote bush of the genus Larrea; also occurs in forested gullies and more open grassland and steppe regions of Patagonia.

behavior

Diurnal, active throughout most of the day, and lives in burrows. Monogamous and establish pair bonds that span several breeding seasons. The mated pair stays in close proximity, and the male tends the female, keeping his guard against other males and predators. Males enurinate over females. Contact between the male and female is maintained by vocalizations consisting of "grumbles." Form colonial groups consisting of communal den sites that house offspring from several different pairs; however, mara mothers attend to only their offspring and visit the den one pair at a time.

feeding ecology and diet

Herbivorous and eats a variety of vegetation including Acacia seeds, cactus, fruits, grasses, herbs, and leaves. Captive animals in zoos subsist on hay, green vegetation, vegetables, and crushed oats. A considerable amount of required water is obtained directly from their diet without the need for drinking standing water.

reproductive biology

Monogamous over several breeding seasons. Gestation is generally 93–100 days, and females tend to reproduce for the first time around eight months of age. Multiple litters are produced, and the litter size is one to two offspring. Females have postpartum estrus. Reproduction in Patagonia tends to be more seasonal.

conservation status

In portions of its range, the mara appears to be declining. While some consider the mara to be vulnerable, the species is not officially listed. Habitat destruction and over-hunting are threatening populations in some areas, especially in the Buenos Aires Province.

significance to humans

Humans have hunted maras for their skins.

Salt-desert cavy

Pediolagus salinicola

subfamily

Dolichotinae

taxonomy

Pediolagus salinicola (Burmeister, 1876), southwest Catamarca Province, Argentina.

other common names

Spanish: Mara chico.

physical characteristics

Head and body length averages 17.1–17.7 in (435–450 mm), tail averages 0.9 in (24 mm), and the weight is 4.6–5.9 lb (2.1–2.7 kg). Basic body form is similar to the mara. The pelage is thick, with the dorsal region being agouti, sides lighter, and the under parts white. Has a distinct band of either white or yellow extending around the flank region to the stomach. Sides of the face are tan colored, and white patches appear behind the eyes. Highly adapted for cursorial locomotion.

distribution

Overlaps with the larger mara, occurring in the southern portion of Bolivia, northern Argentina, and the Chaco of Paraguay.

habitat

Prefers low, arid or semiarid flats characterized by thorn scrub and woody vegetation. Also occurs in temperate steppe regions.

behavior

Diurnal and digs burrows. Forms social groups consisting of an adult pair and young. Animals scent mark and reveal play activity characterized by frisky hops and rolling in sand where scent marking has occurred. Females tend to nurse their young while sitting in open areas, and males tend to show little evidence of extended parental care. Vocalizations are warning calls consisting of a whine. Relationship among individuals is a linear male dominance hierarchy, and alpha males dominate subordinates with aggressive encounters. Females are less aggressive toward each other.

feeding ecology and diet

Herbivorous, with dietary preferences that vary seasonally. In the Chaco region, the diet consists of over 28 species of forbs, 26 species of shrubs, and eight species of grasses. The most popular food items were plant species not preferred by livestock. Grasses preferred during the rainy season, and succulent vegetation during the dry season. Generally forage on lower leaves of bushes, but also stand upright and feed on higher vegetation by grasping with front paws. They have been observed to climb during foraging.

reproductive biology

Gestation period averages 77 days in the wild and approximately 75 days in captive populations. Two offspring are born per litter, and young are weaned around four weeks of age.

conservation status

Not listed by the IUCN.

significance to humans

None known.

Resources

Books

Eisenberg, J. F. "The Function and Motivational Basis of Hystricomorph Vocalizations." In The Biology of Hystricomorph Rodents, edited by I. W. Rowlands and Barbara J. Weir. London: Academic Press, 1974.

Kleiman, D. G. "Patterns of Behaviour in Hystricomorph Rodents." In The Biology of Hystricomorph Rodents, edited by I. W. Rowlands and Barbara J. Weir. London: Academic Press, 1974.

Lacher, T. E. "The Comparative Social Behavior of Kerodon rupestris and Galea spixii and the Evolution of Behavior in the Caviidae." In Bulletin of the Carnegie Museum of Natural History, Number 17, edited by Hugh H. Genoways, Duane A. Schlitter, and Stephen L. Williams. Pittsburgh: Trustees of Carnegie Institute, 1981.

Macdonald, D. The New Encyclopedia of Mammals. Oxford: Oxford University Press, 2001.

Nowak, R. M. Walker's Mammals of the World. Vol. 2. Baltimore: Johns Hopkins University Press, 1991.

Olrog, C. C., and M. Lucero. Guia de Los Mamiferos Argentinos. Tucuman, Argentina: Fundacion Miguel Lillo, 1981.

Redford, K. H., and J. F. Eisenberg. Mammals of the Neotropics: The Southern Cone. Vol. 2. Chicago: University of Chicago Press, 1992.

Wilson, D. E., and D. M. Reeder. Mammal Species of The World. Washington, DC: Smithsonian Institution Press, 1993.

Woods, C. A. "Hystricognath Rodents." In Orders and Families of Mammals of the World, edited by J. Knox Jones and Sydney Anderson. New York: John Wiley and Sons, 1984.

Periodicals

Campos, C. M., M. F. Tognelli, and R. A. Ojeda. "Dolichotis patagonum." Mammalian Species 652 (2001): 1–5

Galante, M. L., and M. H. Cassini. "Seasonal Variation of a Cavy Population in the Pampa Region, East-Central Argentina." Mammalia 58 (1994): 549–556.

Ganslosser, U., and S. Wehnelt. "Juvenile Development as Part of Extraordinary Social System of the Mara Dolichotis patagonum (Rodentia: Caviidae)." Mammalia 61 (1997): 3–15.

Keil, A., J. T. Epplen, and Norbert Sachser. "Reproductive Success of Males in the Promiscuous-mating Yellow-toothed Cavy (Galea musteloides)." Journal of Mammalogy 80 (1999): 1257–1263.

Kunkele, J., and H. N. Hoeck. "Communal Suckling in the Cavy Galea musteloides." Behavioral Ecology and Sociobiology 37 (1995): 385–391.

Rood, J. P. "Ecological and Behavioural Comparisons of Three Genera of Argentine Cavies." Animal Behaviour Monographs, 5 (1972): 1–83.

Rosati, V. R., and E. H. Bucher. "Seasonal Diet of the Chacoan Cavy (Pediolagus salinicola) in the Western Chaco, Argentina." Mammalia 56 (1992): 567–574.

Rowe, D. L., and R. L. Honeycutt. "Phylogenetic Relationships, Ecological Correlates, and Molecular Evolution Within the Cavioidea (Mammalia, Rodentia)." Molecular Biology and Evolution 19 (2002): 263–277.

Sachser, N. "Of Domestic and Wild Guinea Pigs: Studies in Sociophysiology, Domestication, and Social Evolution." Naturwissenschaften 85 (1998): 307–317.

Sachser, N., E. Schwarz–Weig, A. Keil., and J. T. Epplen. "Behavioural Strategies, Testis Size, and Reproductive Success in Two Caviomorph Rodents with Different Mating Systems." Behaviour 136 (1999): 1203–1217.

Tognelli, M. F., C. M. Campos, and R. A. Ojeda. "Microcavia australis." Mammalian Species 648 (2001): 1–4.

Tognelli, M. F., C. M. Campos, R. A. Ojeda, and V. G. Roig. "Is Microcavia australis (Rodentia: Caviidae) Associated with a Particular Plant Structure in the Monte Desert of Argentina?" Mammalia 59 (1995): 327–333.

Taber, A. B., and D. W. Macdonald. "Communal Breeding in the Mara, Dolichotis patagonum." Journal of Zoology 203 (1984): 439–452.

——. "Spatial Organization and Monogamy in the Mara Dolichotis patagonum." Journal of Zoology 227 (1992): 417–438.

Rodney L. Honeycutt, PhD