The
capybara (
Hydrochoerus hydrochaeris) is a large
rodent of the genus
Hydrochoerus of which the only other extant member is the
lesser capybara (
Hydrochoerus isthmius). The capybara is the largest rodent in the world. Close relatives are
guinea pigs and
rock cavies, and it is more distantly related to the
agouti,
chinchillas, and the
coypu. Native to
South America, the capybara inhabits
savannas
and dense forests and lives near bodies of water. It is a highly social
species and can be found in groups as large as 100 individuals, but
usually lives in groups of 10–20 individuals. The capybara is not a
threatened species and is hunted for its meat and
hide and also for a grease from its thick fatty
skin which is used in the pharmaceutical trade.
[2]
Etymology
Its
common name is derived from
Tupi ka'apiûara, a complex agglutination of
kaá (leaf) +
píi (slender) +
ú (eat) +
ara (a suffix for agent nouns), meaning "one who eats slender leaves", or "grass-eater".
[3] The
scientific name, both
hydrochoerus and
hydrochaeris, comes from
Greek ὕδωρ (
hydor = water) + χοίρος (
choiros = pig, hog).
[4][5]
Classification and phylogeny
The capybara and the
lesser capybara belong to the subfamily
Hydrochoerinae along with the
rock cavies. The living capybaras and their
extinct relatives were previously classified in their own family Hydrochoeridae.
[6] Since 2002, molecular phylogenetic studies have recognized a close relationship between
Hydrochoerus and
Kerodon[7] supporting placement of both genera in a subfamily of
Caviidae.
[4]
Paleontological classifications have yet to incorporate this new
taxonomy and continue to use Hydrochoeridae for all capybaras, while
using Hydrochoerinae for the living genus and its closest fossil
relatives, such as
Neochoerus.
[8][9]
The taxonomy of fossil hydrochoerines is also in a state of flux. In
recent years, the diversity of fossil hydrochoerines has been
substantially reduced.
[8][9] This is largely due to the recognition that capybara
molar teeth show strong variation in shape over the life of an individual.
[8]
In one instance, material once referred to four genera and seven
species on the basis of differences in molar shape is now thought to
represent differently aged individuals of a single species,
Cardiatherium paranense.
[8]
Description
Taxidermy specimen of a Capybara.
The capybara has a heavy,
barrel-shaped
body and short head, with reddish-brown fur on the upper part of its
body that turns yellowish-brown underneath. Its sweat glands can be
found in the surface of the hairy portions of its skin, an unusual trait
among rodents.
[6]
The animal lacks under hair, and guard hair differs little from over
hair. Adult capybaras grow to 106 to 134 cm (3.48 to 4.40 ft) in length,
stand 50 to 62 cm (20 to 24 in) tall at the
withers, and typically weigh 35 to 66 kg (77 to 146 lb), with an average in the Venezuelan
llanos of 48.9 kg (108 lb).
[10][11][12] The top recorded weights are 91 kg (201 lb) for a wild female from Brazil and 73.5 kg (162 lb) for a wild male from Uruguay.
[6][13] The
dental formula is
1.0.1.31.0.1.3.
[6] Capybaras have slightly
webbed feet and
vestigial tails.
[6]
Their hind legs are slightly longer than their forelegs; they have
three toes on their rear feet and four toes on their front feet.
[14]
Their muzzles are blunt, with nostrils, and the eyes and ears are near
the top of their heads. Females are slightly heavier than males.
Its
karyotype has
2n = 66 and
FN = 102.
[4]
Ecology
Capybaras are
semiaquatic mammals
[12] found throughout almost all countries of South America except
Chile.
[15] They live in densely
forested areas near bodies of water, such as lakes, rivers,
swamps, ponds, and
marshes,
[11] as well as flooded
savannah and along rivers in
tropical forest. Capybara have flourished in cattle ranches.
[6] They roam in home
ranges averaging 10 hectares (25 acres) in high-density populations.
[6]
Many escapees from captivity can also be found in similar watery habitats around the world. Sightings are fairly common in
Florida, although a breeding population has not yet been confirmed.
[16] In 2011, one was spotted in the
Central Coast of California.
[17]
Diet and predation
Capybaras are
herbivores, grazing mainly on grasses and
aquatic plants,
[11][18] as well as
fruit and tree bark.
[12] They are very selective feeders
[19]
and feed on the leaves of one species and disregard other species
surrounding it. They eat a greater variety of plants during the dry
season, as fewer plants are available. While they eat grass during the
wet season, they have to switch to more abundant reeds during the dry
season.
[20] Plants that capybaras eat during the summer lose their nutritional value in the winter, so are not consumed at that time.
[19] The capybara's jaw hinge is not perpendicular, so they chew food by grinding back-and-forth rather than side-to-side.
[21] Capybaras are auto
coprophagous, meaning they eat their own
feces as a source of bacterial
gut flora, to help
digest the
cellulose
in the grass that forms their normal diet, and to extract the maximum
protein and vitamins from their food. They may also regurgitate food to
masticate again, similar to cud-chewing by
cattle.
[22]
As is the case with other rodents, the front teeth of capybaras grow
continually to compensate for the constant wear from eating grasses;
[15] their cheek teeth also grow continuously.
[21]
Like its relative the guinea pig, the capybara does not have the capacity to synthesize
vitamin C, and capybaras not supplemented with vitamin C in captivity have been reported to develop gum disease as a sign of
scurvy.
[23]
They can have a
lifespan of 8–10 years,
[24] but live less than four years in the wild, as they are "a favourite food of
jaguar,
puma,
ocelot,
eagle, and
caiman".
[15] The capybara is also the preferred
prey of the
anaconda.
[25]
Social organization
Capybaras have a scent gland on their noses, called a morillo.
Capybaras are
gregarious.
While they sometimes live solitarily, they are more commonly found in
groups around 10–20 individuals, with two to four adult males, four to
seven adult females, and the remainder juveniles.
[26] Capybara groups can consist of as many as 50 or 100 individuals during the dry season
[22][27] when the animals gather around available water sources. Males establish social bonds, dominance, or general group census.
[27] They can make dog-like barks
[22] when threatened or when females are herding young.
[28]
Capybaras have two types of scent glands; a morillo, located on the snout, and anal glands.
[29]
Both sexes have these glands, but males have much larger morillos and
use their anal glands more frequently. The anal glands of males are also
lined with detachable hairs. A crystalline form of scent secretion is
coated on these hairs and is released when in contact with objects such
as plants. These hairs have a longer-lasting scent mark and are tasted
by other capybaras. Capybaras scent-mark by rubbing their morillos on
objects, or by walking over scrub and marking it with their anal glands.
Capybaras can spread their scent further by urinating; however, females
usually mark without urinating and scent-mark less frequently than
males overall. Females mark more often during the wet season when they
are in
estrus. In addition to objects, males also scent-mark females.
[29]
Reproduction
Mother with typical litter of four pups
When in estrus, the female's scent changes subtly and nearby males begin pursuit.
[30] In addition, a female alerts males she is in estrus by whistling though her nose.
[22]
During mating, the female has the advantage and mating choice.
Capybaras mate only in water, and if a female does not want to mate with
a certain male, she either submerges or leaves the water.
[22][27] Dominant males are highly protective of the females, but they usually cannot prevent some of the subordinates from copulating.
[30]
The larger the group, the harder it is for the male to watch all the
females. Dominant males secure significantly more matings than each
subordinate, but subordinate males, as a class, are responsible for more
matings than each dominant male.
[30] The lifespan of the capybara's sperm is longer than that of other rodents.
[31]
Capybara
gestation is 130–150 days, and produces a
litter of four capybara young on average, but may produce between one and eight in a single litter.
[6]
Birth is on land and the female rejoins the group within a few hours of
delivering the newborn capybaras, which join the group as soon as they
are mobile. Within a week, the young can eat grass, but continue to
suckle—from any female in the group—until weaned around 16 weeks. The
young form a group within the main group.
[15] Alloparenting has been observed in this species.
[27] Breeding peaks between April and May in Venezuela and between October and November in
Mato Grosso, Brazil.
[6]
Activities
Though quite agile on land (capable of running as fast as a
horse),
[32]
capybaras are equally at home in the water. They are excellent
swimmers, and can remain completely submerged up to five minutes,
[11] an ability they use to evade
predators. Capybaras can sleep in water, keeping only their noses out of the water. As temperatures increase during the day, they
wallow in water and then graze during the late afternoon and early evening.
[6] They also spend time wallowing in mud.
[14] They rest around midnight and then continue to graze before dawn.
Conservation and human interaction
Video of captive capybaras resting at
Ueno Zoo in Japan
Capybaras are not considered a
threatened species;
[1] their
population is stable throughout most of their South American range, though in some areas hunting has reduced their numbers.
[11][15]
Capybaras are hunted for their meat and
pelts in some areas,
[33] and otherwise killed by humans who see their grazing as competition for
livestock. In some areas, they are
farmed, which has the effect of ensuring the
wetland habitats are protected. Their survival is aided by their ability to breed rapidly.
[15]
Capybaras have adapted well to the urbanization in South America. They can be found in many areas in
zoos and
parks,
[21] and may live for 12 years in
captivity.
[15]
Capybaras are gentle and usually allow humans to pet and hand-feed
them, but physical contact is normally discouraged, as their ticks can
be vectors to
Rocky Mountain spotted fever.
[34]
The
European Association of Zoos and Aquaria asked
Drusillas Park in
Alfriston,
Sussex, to keep the
studbook
for capybaras, to monitor captive populations in Europe. The studbook
includes information about all births, deaths and movements of
capybaras, as well as how they are related.
[35]
Capybaras are farmed for meat and skins in South America.
[36] The meat is considered unsuitable to eat in some areas, while in other areas it is considered an important source of protein.
[6] In parts of South America, especially in Venezuela, capybara meat is popular during
Lent and
Holy Week as the
Catholic Church previously gave a special dispensation that allows for its consumption while
other meats are generally forbidden.
[37]
Although it is illegal in some
states,
[38] capybaras are occasionally kept as pets in the United States.
[39]
