Geographic Range
Atelocynus microtis
is native to the northern part of South America and has been found in the Amazon
basin regions of Brazil, Peru, Ecuador and Colombia. It has also been sighted in the
upper Rio Orinoco basin in Colombia and Venezuela and the upper Rio Parana basin in
Mato Grosso, Brazil.
- Biogeographic Regions
- neotropical
Habitat
Atelocynus microtis
prefers undisturbed lowland rainforests in the Amazon region. Within these lowland
forests, there are records of
A. microtis
occupying terra firme forest, swamp forest, stands of bamboo and areas of primary
succession along rivers, and there have been several reports of small-eared dogs swimming
in rivers along with a prevalence of tracks along riverbanks and creeks. Whether or
not they are able to use other habitats is still unknown, but there has been one sighting
of an individual in a lowland forest that bordered savanna. There are very few records
of
A. microtis
in areas with significant human activity or impact.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
- rainforest
- Wetlands
- swamp
- Other Habitat Features
- riparian
Physical Description
Atelocynus microtis
is a mid-sized
canid
with a large, fox-like head, short ears that are rounded at the tips, relatively
short legs, and a long, bushy tail. Small-eared dogs have thick, sleek, dark pelage
that may be in shades of brown, black, or gray and gradually fades into a dull reddish-brown
on the underside. Markings include a narrow black collar, a dark band that extends
along the top of the back and tail, and a patch of light-colored hairs around the
pubic region and underside of the base of the tail. Individuals may exhibit different
color patterns, but it remains unclear if these variations reflect age, distribution,
molt, or other factors.
Possibly because of their propensity to use water sources, small-eared dogs have a
partial interdigital membrane. A pair of captive individuals were also described as
having a notably visible
tapetum lucidum
, which caused the eyes to reflect brightly in conditions of low light. Compared to
related species of
South American foxes
, small-eared dogs are fairly large. They have relatively short limbs and small ears
compared to similar species and females are slightly larger than males.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
Reproduction
Little information is known about the mating system of
A. microtis
and no information has been published on this topic. Females have been found with
pups on rare occasions but no information is available regarding how mates are attracted
or how their mating system works.
General reproductive behavior has not been formally studied in
A. microtis
, so little is known. Based on the finding of a juvenile carcass, it is believed that
small-eared dogs give birth in May or June. Pups have also been found in the months
of April, September, November, and December, suggesting that parturition occurs during
the dry season. However, when breeding occurs and the length of gestation is unknown.
Adults have been found with 2 or 3 pups in dens in hollow logs or
paca
burrows. Information on weaning or when pups reach sexual maturity is not known.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
Because studies of parental investment have not been formally conducted in
A. microtis
, little is known about the extent of the investment made at various stages of development.
However, like all mammals, females invest substantially in gestation and lactation
and young have been observed with females, suggesting some period of dependency.
- Parental Investment
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
provisioning
Lifespan/Longevity
Nothing is known of the expected lifespan of
A. microtis
in the wild. In captivity, most short-eared dogs do not survive a full year. However,
two captive animals have lived for 9 and 11 years, respectively.
Behavior
Much of what is known about A. microtis comes from observations of a few captive specimens. In observations of a captive pair at the Brookfield Zoo in Chicago, IL, it was noted that the male was dominant over the female despite his smaller size. The male also produced secretions from his anal glands when startled or threatened, producing a strong, musky odor. This odor did not seem to be present in the female. When one of the individuals was startled or felt threatened it would growl, bare its teeth, and attempt to bite. A report from a small group of hunters with domestic dogs in Brazil of a mother with pups showing aggression in defending her young and attacking one of the domestic dogs seems to support these observations. Atelocynus microtis has also been observed erecting the hairs on the tip of its tail when it becomes excited, suggesting the common name given to these dogs by the natives of the Rio Tapojoz region of Brazil: “flag-tailed wild dogs."
Multiple sightings of small-eared dogs in and around rivers, coupled with their partial
interdigital membrane, have led to the belief that they are at least partially aquatic.
There is limited data pertaining to the social structure of small-eared dogs. Aside
from a few sightings of pairs of small-eared dogs, the data seems to point toward
A. microtis
being a largely solitary animal. They are considered diurnal because 95% of the observations
of
A. microtis
during field research were made during the day. However, it is suspected that this
is due at least in part to when observers were present, since they have been photographed
walking and swimming at night. Small-eared dogs may be active at any time of the day
or night.
- Key Behaviors
- terricolous
- diurnal
- nocturnal
- crepuscular
- motile
- solitary
Home Range
No information is available on home range size.
Communication and Perception
There is very little data on communication in small-eared dogs. Given their strong
odor, the anal gland secretions are likely used as a device for communication. Also,
the displays of aggression such as bared teeth and growling are almost certainly used
as a warning to ward off potential threats.
- Other Communication Modes
- pheromones
- scent marks
Food Habits
An ongoing study at the Cocha Cashu Biological Station using scat samples to better
understand the diet of
A. microtis
has provided a significant amount of information. Small-eared dogs are generalist
carnivores, but also appear to eat some fruits as well. The most prevalent item in
their diet appears to be fish, which has been supported by the findings of Defler
and Santacruz, who discovered the parasite
Diphyllobothrium latum
, which requires fish as an intermediary host, in the intestine of a museum specimen.
Scat samples also contained
insects
and the remains of mammals such as
agoutis
,
marsupials
, and
small rodents
. About 10% of the samples contained the remains of fruits such as
Borismenia japurensis
,
Strychnos asperula
,
Unonopsis floribunda
,
Pouteria procera
,
Sciadotenia precatoria
,
Trattinnickia
species, and various
Cucurbitaceae
and
Maraceae
. In a couple of scat samples,
Euterpe precatoria
fruit was germinating. While they do not appear to be a major component of the small-eared
dog’s diet, remnants of
frogs
,
crabs
,
reptiles
, and vegetable fiber were also found in some samples. There have also been some reports
of
A. microtis
eating fallen
Brosimum
fruits and bananas as well as killing and eating poultry. Captive individuals in
Bogota, Colombia were fed raw meat, kikuyu grass shoots, and foods that humans would
typically eat.
- Animal Foods
- birds
- mammals
- amphibians
- reptiles
- fish
- insects
- aquatic crustaceans
- Plant Foods
- leaves
- fruit
Predation
There are no unequivocal data on what animals (if any) prey on
A. microtis
, but the presence of
ocelot
tracks around the remains of a juvenile in Cocha Cashu suggest that it may be a predator.
Jaguars
and
pumas
may also be predators due to their size and presence in the same habitats as
A. microtis
.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Little information is known about the general ecology of
A. microtis
as it is such an elusive species. Because
A. microtis
has a sleek, thick coat, it is suggested that it inhabits areas near water or with
heavy rainfall and its short limbs allow for it to move about easily within dense
forests. Small-eared dogs are generalist carnivores, preying on
fish
,
insects
,
small mammals
,
amphibians
,
birds
, and
reptiles
. They are also thought to be seed dispersers, as germinating fruit seeds have been
found in their scat. They may be prey to
ocelots
,
jaguars
, and
pumas
.
Small-eared dogs are hosts to various viruses. Common canine distemper virus and canine
parvovirus affect this species and are transmitted through
domestic and feral dogs
. They are hosts to the cestode
Diphyllobothrium latum
, which requires a fish intermediate host.
- Ecosystem Impact
- disperses seeds
- cestodes ( Diphyllobothrium latum )
Economic Importance for Humans: Positive
Because small-eared dogs are so elusive, there have been only a few reports of them
having positive economic importance for humans. Short-eared dogs are occasionally
hunted for meat, although not for fur. They have been captured in some cases for pets
and for sale to local people and zoos. These instances, however, are rare.
Economic Importance for Humans: Negative
Atelocynus microtis
has no negative economic impact on humans directly, although it can carry the diseases
canine distemper virus and canine parvovirus, both of which can occur in
domestic and feral dogs
. It is probably commoner, however, for domestic and feral dogs to transmit diseases
to the short-eared dog.
- Negative Impacts
- causes or carries domestic animal disease
Conservation Status
With a population estimated at only 15,000 individuals, short-eared dogs are one of
the rarest species of carnivores in South America. They are listed as near threatened
according to IUCN’s Red List of Threatened Species. The major threats to this species
are habitat loss and transmission of diseases from
domestic dogs
. These diseases include canine distemper virus and canine parvovirus. There are few
reports of short-eared dogs being hunted for meat and no reports of hunting for fur.
Short-eared dogs are not listed on any CITES appendix, but they are listed as an endangered
species and protected by law in Brazil, and are currently on a preliminary list of
endangered species in Colombia. In Peru, the species was recently taken off the list
of protected species. Although there are efforts to protect short-eared dogs in some
South American countries, no conservation efforts have been made to increase population
numbers. Furthermore, at present no known short-eared dogs are being held in captivity,
although there have been individuals held in zoos in the past.
There is ongoing research being conducted on short-eared dogs in Peru. Efforts are
being made to provide vaccinations for domestic dogs in the range of short-eared dogs
in order to prevent disease transmission and there are efforts in place to expand
studies of their ecology and conservation outside of Peru.
Other Comments
The generic name Atelocynus comes from the Greek words "ateles" (imperfect) and "cyon" (dog) while microtis is formed from the Greek words "micros" (small) and "ot" (ear).
Atelocynus microtis
is referred to as "huiwa toto" by the Amarakaeri people of Peru. The term means "solitary
devil", and was given to the species due to the belief that it attacks men by biting
their testicles.
Additional Links
Contributors
Emily Fieweger (author), University of Michigan-Ann Arbor, Sam Giraud (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor, Tanya Dewey (editor), Animal Diversity Web.
- 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.
- swamp
-
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
- 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).
- seasonal breeding
-
breeding is confined to a particular season
- 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.
- diurnal
-
- active during the day, 2. lasting for one day.
- nocturnal
-
active during the night
- crepuscular
-
active at dawn and dusk
- motile
-
having the capacity to move from one place to another.
- solitary
-
lives alone
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- pheromones
-
chemicals released into air or water that are detected by and responded to by other animals of the same species
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- 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.
- pet trade
-
the business of buying and selling animals for people to keep in their homes as pets.
- food
-
A substance that provides both nutrients and energy to a living thing.
- causes or carries domestic animal disease
-
either directly causes, or indirectly transmits, a disease to a domestic animal
- carnivore
-
an animal that mainly eats meat
- piscivore
-
an animal that mainly eats fish
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
References
Berta, A. 1986. Atelocynus microtis. Mammalian Species , 256: 1-3.
Leite, M., R. Williams. 2008. "2008 IUCN Red List of Threatened Species" (On-line). Atelocynus microtis. Accessed April 18, 2009 at http://www.iucnredlist.org/details/6924 .
Leite Pitman, M., R. Williams. 2004. Ecology and Conservation of the Short Eared Dog (Atelocynus microtis) at Cocha Cashu Biological Station, Peru. Pp. 26-31 in Canids: Foxes, Wolves, Jackals, and Dogs - Species Status and Conservation Action Plan, 2nd Edition . Cambridge, UK: IUCN/SSC Canids Specialist Group. Accessed April 18, 2009 at http://web.duke.edu/~manu/Projects/atelocynus.htm .
Macdonald, D. 2006. Foxes. Pp. 40, 55, 61 in The Encyclopedia of Mammals , Vol. 1, 3 Edition. Oxford, UK: Oxford Press.