TAXONOMY & NOMENCLATURE

(McKenna & Bell 1997) (Mead et al 2007)(Rowe & Honeycutt 2002) (Wilson & Reeder 2005) (Wyss. et al 1993) (Kurtén & Anderson 1980)

Describer (Date): Linnaeus, 1766. Systema Naturae, 12th ed., 1:103 for Hydrochoerus hydrochaeris
                           Goldman, 1912. Smithsonian Miscellaneous Collection, 60(2):11 for H. isthmius
Kingdom: Animalia
    Phylum: Chordata
        Class: Mammalia
             Order: Rodentia
                    Family: Hydrochoeridae
                           Genus: Hydrochaeris - Brunnich 1772
                                 Species: Hydrochaeris hydrochaeris
                               Species: H. isthmius

Taxonomic History and Nomenclature

Common Name

Scientific Name

Phylogeny

DISTRIBUTION & HABITAT

(Herrera & Macdonald 1989) (Mones & Ojasti 1986) (Verdade &. Ferraz 2006)

Distribution

Habitat

PHYSICAL CHARACTERISTICS

(Herrera 1992) (MacDonald 1984) (Mones & Ojasti 1986) (Pereira et al 1980) (Nowak 1999)



Body Weight: Average adult 48.9 kg (108 lb); 35 to 65.5 kg (77 lb to 144 lb) in Venezula's Llano region; a record 91 kg (200 lb) in southern Brazil
Head/Body Length: 106 to 134 cm (42 to 53 in);
Shoulder Height: 60.9 cm (2 ft.)
Tail Length: Tail vestigal

General

Pelage and Skin

Sexual Dimorphism

Other Physical Characteristics

BEHAVIOR & ECOLOGY

(Lord-Rexford 1994) (Herrera & Macdonald 1989, 1993)
(Macdonald 1981a, b) (Nowak 1999) (Ojasti 1991) (Rowe and Honeycutt 2002)(Tomazzoni et al 2005)

Activity Cycle

Territory Size

Social Groups

General

Hierarchy

Territorial Behavior

Aggression

  • Grooming lessens tension between individuals and removes parasites
  • Male aggression more frequent with increasing numbers of males in group
  • Harassment and chasing: main form of male/male aggression
      • Subordinate males rarely retaliate
      • Retaliation involves facing opponent, both animals rushing towards each other, rearing on hind legs, grappling, loser fleeing
      • Subordinate males often suffer serious bites to rump as they flee
      • Most commonly, dominant male walks, nudges, or "escorts" subordinate male to edge of group
Play
  • Young in groups play in water, imitate males
  • Like other cavy-like social rodents, individuals chase each other, play-wrestle, gallop

Communication

Visual Signs

  • Greatly enlarged scent glands on top of snout in male signals status & may attract females
  • Size of male's morrillo a sign of rank
  • Amount of scent-marking correlates with dominance rank    

    Vocalization

    • Infants and young constantly emit a guttural purr, perhaps to stay in touch with group; losers in aggressive matches also make this sound in appeasement
    • Low clicking sounds of contentment
    • Sharp prolonged whistles, squeals, short grunts
    • Alarm bark or cough
    • Most warning calls come from subordinate males in a group; companions react by standing alert or plunging into nearest water
    • Females emit a whistle when in estrus
    • Males tooth-chatter as sign of aggression
    • Many other closely related species also highly vocal, especially guinea pigs and cavies

    Olfaction/Scent Marking
    • Both sexes scent mark with anal gland; females less frequently
    • Group members may recognize each other by their unique mix of scent chemicals

    Locomotion
    • Excellent swimmer; good diver, can stay underwater for up to 5 minutes
    • Move from place to place in short bursts of travel not more than 200 m. (.12 mi.) with long rests between
    • Walks, grazing, in typical day about 700 m (.43 mi)
    • Star-shaped footprints
    • Rather sedentary habits allow ranchers to manage capybara without fences
    • Several juveniles may ride on female's back as she swims

    Interspecies Interaction
    • Puma & jaguar prey on capybara
    • When attacked by wild dogs, capybara group forms defensive huddle with young in center, adults facing outwards
    • Juveniles preyed upon by foxes, ocelots, cayman, raptors, occasional possums (attacking infants), anaconda
    • Co-exist with domestic cattle
    • At least nine species of birds increase their feeding rate by associating with capybara
      • Especially jacana, scarlet ibis, sharp-tailed Ibis, white Ibis, buff-necked ibis, swifts
      • Egrets hunt from moving and stationary capybara's backs
      • Swifts hunt low overhead or from capybara's head
      • Researcher observed capybara soliciting tick-eating (Amblyomma spp.) by yellow-headed caracara
    • Five bird species associated with capybara in order to find food. (Tomazzoni et al 2005)
      • Southern caracara, rufous hornero, cattle tyrant, yellow-headed caracara, shiny cowbird
      • Strategies of the birds included using the capybara as a perch, walking with the capybara to catch flushed prey, foraging in capybara skin

    DIET & FEEDING

    (Barreto and Herrera 1998) (Borges & Colares) (Nowak 1999) (Quintana et al 1998)

    Anatomy and Physiology

  • Digestive system similar to rabbit's
    • Simple stomach
    • Large intestinal pouch (caecum) with microorganisms for fermenting cellulose
    • Excrete two kinds of feces
      • Olive colored oval balls
      • Also colorless, protein rich "paste" which is re-ingested for maximum digestion of nutrients (= coprophagy)
    • Regurgitate and re-chew food while resting
  • Front incisors crop native grasses too short for cattle

Feeding Strategies and Food Items

  • Are selective grazers; eat approximately 3 kg/day fresh forage, mainly grasses
    • Tend to be more selective when more plant species available
    • 80% of diet is only 5 species of grasses (Poaceae)
    • Most common plant species in areas typically the ones eaten most often, especially in winter when fewer species available
    • Various estimates for amount of aquatic plants in diet from .6 % to 87 %
      • As wet season advances, more reeds and water hyacinths consumed
  • Capybaras raid cultivated fields for grains, melons, squashes, bananas, sweet potatoes, manioc leaves and corn

REPRODUCTION & DEVELOPMENT

(Macdonald and Herrera 2001) (Nogueira et al 1999) (Ojasti. 1968) (Paula et al 1999) (Rowlands and Weir 1974) (Weigl 2005)

Courtship

  • Female estrus cycle: every 7.5 days; remain receptive only 8 hours
  • In mating season, dominant males conspicuously guard females
  • When female in estrus, dominant male sniffs her frequently
  • Female whistles when in estrus to attract males
  • Mating season year round with peak at beginning of wet season

Reproduction

  • One litter/yr; two litters possible under good conditions
  • Harem-based polygynous breeding (one dominant male, several females)
  • Female pursued by male enters water and swims back and forth
    • Pair mates in water; female often submerged for brief copulation
    • Females not wanting to mate may dive deep enough to dislodge male
  • Mating pair often interrupted by a second male
  • Life span of male's sperm longer than that in most rodents; capybara mating system promotes sperm competition
  • Group association essential for raising young; groups smaller than four adults fail to rear any young

Gestation

  •  150 days

Life Stages    

Birth

  • 4 to 5 pups most common; a breeding group may have 15 pups or more at one time
  • At birth young weigh about 1,500 grams (3.3 lb)
  • At birth all cheek teeth already erupted, with signs of wear (Kramarz 2002)
  • Young can follow mother and eat grass shortly after being born (are precocial)
  • Young nurse about 16 weeks

Infant (< 1 year old)

  • Young may suckle indiscriminately from several females;
  • Small groups of young move about herd, nudging females until one stands to allow nursing
  • Very young ride on females' backs'
  • Very young avoid water where caimen and anaconda lurk
  • Females spend a lot of time caring for young of different ages

Juvenile

  •  Yearlings disperse from parents' group

Subadult

  •  By 18 mos. weigh about 40 kg (88 lb.)

Adult

  • Females sexually mature age 7 to 12 mos.
  • Males between 15 and 24 mos.

Longevity

  •  Average life span 7-10 years;
  • In captivity in the Adelaide Zoo in Australia, 15 years
  • One H. isthmius at the San Diego Zoo: 9 years, 6 mos.

Mortality

  • Preyed upon by foxes, bush dogs, feral dogs, ocelots, cayman, jaguars, eagles, caracaras, black vultures and human hunters
  • Wild capybara, especially in Venezuela, are poached and illegally hunted more intensely in the weeks before Easter, when they are a sanctioned by the Catholic Church as a substitute for fish (because of their semi-aquatic habits).
  • Jaguars prey most often on young males at the periphery of the group (and furthest from the water)
  • Infanticide in captive populations, but not in wild

DISEASES AND PATHOLOGY

(Labruna et al 2004, 2007) (Lord & Flores 1983)(Mones & Ojasti 1986) (Meireles et al 2007) (Saraiva 2004)

Diseases & pathogens in wild capybara

  • Parasites include species of intestinal protozoa (Ciliata), spore-producing parasitic protozoa (Apicomplexa), parasitic worms or flukes (Trematoda), tapeworms (Cestoda), roundworms (Nematoda), insects and fungi.
  • Rare case of natural infection with avian eye trematode Philophthalmus lachrymosus;
    • This parasite also infects humans
  • Carry Cryptosporidium, a protozoa causing gastro intestinal infections in humans;
    • Safety of human water supplies near capybara populations is a concern
  • Bites and massive lesions from Amblyomma (Ixodidae) ticks carrying Rickettsia rickettsii bacteria
    • This pathogen responsible for Brazilian Spotted Fever in humans
    • In southeastern Brazil incidence this disease may be rising due to capybara populations moving into urban areas (and vice versa)
  • Blood studies show capybara may host two species of a Brucella bacteria, B. suis and B. abortus
    • Infect pigs and cattle
    • Symptoms of this disease in capybara not known
  • Carry a parasitic protosoa, Trypanosoma evansi
    • Some capybara with the parasite appear in perfect health; others show signs of weight loss, apathy, lack of coordination of hindlimbs, hair loss, eye infections, enlarged spleen, death
    • T. evansi reported in capybara populations in Argentina, Brazil, Panama, Paraguay
    • T. evansi causes disease of horses and wildlife ("mal de caderas" in Argentina)
      • Most common in first half of wet season when prolonged flooding reduces available habitat
      • Anecdotal reports that trypanosomiasis is milder for horses living in areas where capybara are common

Diseases In Captivity

  • Mange or scabies from mites (Sarcoptes scabiei), a common skin problem in animals without water access
  • Wounds from male-male aggression a problem
  • Scurvy in animals without source of Vitamin C
    • Symptoms included bleeding gums and noses, tooth loss, fragile bones, disruption of reproduction in males and females, death
  • Can be experimentally infected with foot-and mouth disease, but natural infection not known

MANAGED CARE

(Chapman 1991) (Nogueira et al 1999)

Captive Breeding

  • Zoo-raised capybara have higher survival rate than those in wild
  • Females in captivity reach sexual maturity later than in wild (26 vs. 18 months)
  • Capybaras bred in many zoos and also commercially for meat and skins in South America
  • Some populations managed in natural areas
  • Problems with enclosed or penned individuals
      • Male/male aggression when overcrowded
      • Hierarchical group social structure disrupted when new individuals introduced
      • Infanticide by female pen mates
        • Females' lack of experience not a factor 
        • No infanticide when females have been raised together (are familiar with each other)
        • No aggression by females except at birth of pen mate's young

POPULATION AND CONSERVATION STATUS

(Moreira & Macdonald,1996) (Ojasti 1991) (Verdade & Ferraz 2006)

Population Density

  • 195 individuals/sq. km. ( 0.4 sq. mi) in southeastern Brazil wetlands
  • Between 10 and 200 individuals/ sq. km.(0.4 sq mi) in Venezuelan llanos
  • Status in all areas depends on management practices
    • Some areas allow controlled harvest and tolerate subsistence hunting
    • Elsewhere all hunting prohibited but poaching may be common
    • Protections enforced in other areas
    • Management for cattle may improve habitat for capybara
    • Populations considered a potential nuisance in east central Sao Paulo Brazil where they often live near humans
      • Blamed for crop damage
      • Associated with Brazilian Spotted Fever

Conservation

1953: Hunting regulated in Venezuela
1967: Hunting prohibited in Brazil (Federal Law No. 5.197) but harvesting being considered to reduce population densities and impact on agriculture in some areas
1968: Venezuela develops management plan using studies of capybara biology and ecology
1980: Hunting prohibited in Columbia
2000: Central Suriname Nature Reserve established on North Atlantic coast of South America; 1.592 million hectares ( 6,146 sq mi.)

  • IUCN Status 2006: Lower Risk; Conservation Dependent (1C).
    • Locally common; farmed for meat and skin in some areas
  • CITES Status: Not listed

Threats to survival

  •   Status not threatened at present, but habitat loss and hunting/farming need controls and monitoring
    • Predators' declines due to habitat loss may offer short-term benefit to capybara populations
    • Hunting often removes larger and older individuals from population (large males, pregnant females) and reduces group size
      • Long-term effect: decrease in body size of hunted population
      • Smaller groups mean fewer young survive per female
      • Hunting drives normally savanah-dwelling animals to forested habitats where resources are not optimal
    • Encroachment of human development
    • Clear-cutting/burning, farming
    • Human perception of their role in competing with cattle for food, as pests of sugarcane and rice mono cultures, or as carriers of diseases

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