Myoprocta acouchyred acouchi

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Geographic Range

Myoprocta acouchy, also known as the red acouchy, can be found in Guyana, Suriname, French Guiana, and Brazil, north of the Amazon and east of the Rio Branco. Isolated populations may be found in Colombia and the upper Rio Vaupes. (Emmons, 1990)

Habitat

The habitat of M. acouchy is dense undergrowth in lowland forests. Red acouchis are usually found around fallen trees that are used as runways. Males prefer open forest while females prefer a closed habitat. At night the red acouchis rest in nests of leaves, usually inside a hollow log. Rarely they can be found using burrows made by other species. When using these burrows, M. acouchy will plug up any entrances not in use with leaves. (Dubost, 1988; Emmons, 1990)

Physical Description

Red acouchis range in total length from 386 mm to 468 mm. With masses between 1.05 kg to 1.45 kg. Red acouchis are dark chestnut-red or orange on the sides and legs. Their mid-back and rump are black or a very dark shade of red. Areas around the mouth and eyes, as well as behind the ears, are almost naked. The whiskers are well developed and are black in color. They have long limbs, the forefeet have four toes and a vestigial thumb with a claw, and the hind feet have three large elongated toes. These toes have hoof-like claws. They have black soles of the bottom of their feet. The mid-back and rump are covered in glossy black or dark red hairs. Some may have an olivaceous appearance. Rump hairs are not banded, which distinguishes them from their close relative Myoprocta pratti, commonly known as green acouchis. Rump hairs are long and straight, hanging over the tail region. Red acouchis have a slender, short tail, which is white underneath as well as at the tip. The tail is often held up, exposing the white underside. (Emmons, 1990)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    1.000 to 4.000 kg
    2.20 to 8.81 lb
  • Range length
    386 to 468 mm
    15.20 to 18.43 in
  • Average basal metabolic rate
    2.8040 cm3.O2/g/hr
  • Average basal metabolic rate
    2.804 W
    AnAge

Reproduction

Red acouchi courtship may be highly ritualized, simular to their close relatives in the genera Dasyprocta and Agouti. What is known about the courtship of red acouchis is that males will mark the ground with anal glands when pursuing females. This is done by dragging the hind quaters across the ground. They will also follow females around with the front legs trembling and emitting a high pitched sound. When aroused, the hair on the back and flanks will stand up and go back down suddenly. Ocassionally males will also splash females with urine. (Eisenberg and Redford, 1999; Eisenberg, 1989)

The actual breeding season of the red acouchis in the wild is not well studied. In captivity the species has been observed breeding year-round. When this occurs, there usually is a peak in births during the summer months. Males are fertile year round, while females go into anestrus during the summer. The estrous cycle for red acouchis averages about 42 days. The gestation period averages 99 days. The number of offspring produced in a single litter is from 1 to 3 young with a average of 2. The young will nurse for 2 to 3 months before becoming fully weaned. Young of both sexes will become sexually mature at approximately 304 days. Post-partum estrus can occur but females will usually mate after the young are fully weaned. (Nowak, 1999)

  • Breeding interval
    Red acouchis can breed multiple times during a year.
  • Breeding season
    In captivity breeding occurs year round. They tend to have a birth peak in the summer months.
  • Range number of offspring
    1.000 to 2
  • Average number of offspring
    2
    AnAge
  • Range gestation period
    94 to 115 days
  • Average gestation period
    99 days
  • Range weaning age
    42.000 to 56.000 days
  • Average age at sexual or reproductive maturity (female)
    304 days
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    304 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    304 days
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    304 days
    AnAge

Young red acouchis are precocial. Even so, they will remain sheltered inside a burrow until they are several weeks old. The mother returns to the nest burrow to nurse the young. Male red acouchis do not help with raising young. (Eisenberg, 1989)

  • Parental Investment
  • precocial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female

Lifespan/Longevity

There is little documentation of the longevity of M.acouchy, the longest living captive animal lived over 10 years. (Grzimek, 1990)

Behavior

There is conflicting information on whether these animals are solitary or social. Emmons states that these animals are solitary, whereas Nowak mentions that these animals will live in social groups usually consisting of one adult male, one adult female, and juveniles. Nowak also states that even though the animals live in groups as big as seven individuals, they seem to use separate home ranges. They are diurnal and move about on the forest floor in a characteristic crouched run. (Emmons, 1990; Nowak, 1999)

  • Range territory size
    6,500 to 12,000 m^2

Home Range

During the wet season the home range of red acouchis ranges between 9,600 sq. meters to 12,000 sq. meters. Home range size is smaller during the dry season, from 6,500 sq. meters to 7,300 sq. meters. (Dubost, 1988; Nowak, 1999)

Communication and Perception

When alarmed, red acouchis stomp their hind feet and emit a whistle. They also emit a series of high pitched sounds, including a screech like squawk. Red acouchis can be detected by listening for the gnawing sounds they make while eating seeds and nuts. (Emmons, 1990)

Food Habits

Red acouchis are herbivorous, eating mainly fruits, nuts, seeds, and the cotyledons of seedlings. They are known for burying seeds in the forest floor for use during the dry season, when food is scarce. (Emmons, 1990)

  • Plant Foods
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit

Predation

Red acouchis are prey to many medium-sized tropical, lowland predators, such as snakes and cats. When threatened by a predator, they emit an alarm call. When they flee, it is usually only for a few yards, where they will then hide motionless in a thicket or behind a fallen log. They have been known to circle silently and approach a motionless observer from behind after originally fleeing in alarm. (Emmons, 1990; Macdonald, 1999)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

The red acouchi behavior of burying seeds helps in the dispersal of seeds of many tree species. Red acouchis are also common prey for many tropical lowland predators. (Macdonald, 1999)

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Red acouchis help with forest regeneration when they bury the seeds of plants species in different places for the use during the dry season. They are also hunted by locals as a valuable meat source. (Nowak, 1999)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

There are no known adverse effects of M. acouchy on humans.

Conservation Status

Red acouchi populations seem stable, they are considered lower risk/least concern by the IUCN.

Other Comments

The scientific name for M. acouchy was formerly Myoprocta exilis. Some of the local common names of M. acouchy are cutiara, acoechi, and maboela. (Emmons, 1990; Woods and Kilpatrick, 2006)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Marisha Jaimes (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

vibrations

movements of a hard surface that are produced by animals as signals to others

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

young precocial

young are relatively well-developed when born

References

Dubost, G. 1988. Ecology and social life of the red acouchy, Myoprocta exilis ; comparison with the orange-rumped agouti, Dasyprocta leporina .. Journal of Zoology, 214: 107-123. Accessed November 01, 2006 at http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=1898352&q=myoprocta+acouchy+dubost&uid=789620774&setcookie=yes.

Eisenberg, J. 1989. Mammals of the Neotropics The Northern Neotropics Danama, Colombia, Venezuela, Guyana, Suriname, French Guiana. Chicago, Illinois: University of Chicago Press.

Eisenberg, J., K. Redford. 1999. Mammals of the Neotropics The Central Neotropics Ecuador, Peru,Bolivia, Brazil. Chicago, Illinois: The University Chicago Press.

Emmons, L. 1990. Neotropical Rainforest Mammals a Field Guide. Chicago, Illinois: The University of Chicago Press.

Grzimek, B. 1990. Grzimek's Encyclopedia Mammals. South Orange, New Jersey: McGraw-Hill Publishing company.

Macdonald, D. 1999. The Encyclepedia of Mammals. New York, New York: Fact of File Inc..

Nowak, R. 1999. Rodentia; Dasyproctidae; Genus Myoprocta acouchis. Pp. 1676 in Walker's Mammals of the World, Vol. 11, 6 Edition. Baltimore and London: The Johns Hopkins University Press.

Woods, C., C. Kilpatrick. 2006. A Taxonomic and Geopgraphic Reference. Pp. 1558 in D Wilson, D Reeder, eds. Mammal Species of the World, Vol. 2, 3 Edition. Baltimore, Maryland: Johns Hopkins University Press.