Geographic Range
Myoprocta exilis
, 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.
- Biogeographic Regions
- neotropical
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.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
- rainforest
- Other Habitat Features
- riparian
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.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
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.
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.
- Key Reproductive Features
- iteroparous
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
- post-partum estrous
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.
- Parental Investment
- precocial
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
provisioning
Lifespan/Longevity
There is little documentation of the longevity of
M.acouchy
, the longest living captive animal lived over 10 years.
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.
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.
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.
- Other Communication Modes
- vibrations
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.
- Plant Foods
- wood, bark, or stems
- seeds, grains, and nuts
- fruit
- Foraging Behavior
- stores or caches food
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.
- 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.
- 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.
- 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.
Additional Links
Contributors
Tanya Dewey (editor), Animal Diversity Web.
Marisha Jaimes (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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).
- 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.
- 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.
- 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).
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- young precocial
-
young are relatively well-developed when born
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- vibrations
-
movements of a hard surface that are produced by animals as signals to others
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- stores or caches food
-
places a food item in a special place to be eaten later. Also called "hoarding"
- 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.
- food
-
A substance that provides both nutrients and energy to a living thing.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
- granivore
-
an animal that mainly eats seeds
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., K. Redford. 1999. Mammals of the Neotropics The Central Neotropics Ecuador, Peru,Bolivia, Brazil . Chicago, Illinois: The University Chicago Press.
Eisenberg, J. 1989. Mammals of the Neotropics The Northern Neotropics Danama, Colombia, Venezuela, Guyana, Suriname, French Guiana . Chicago, Illinois: University of 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 Mammal Species of the World , Vol. 2, 3 Edition. Baltimore, Maryland: Johns Hopkins University Press.