Geographic Range
Ethiopian dwarf mongooses (
Helogale hirtula
) are sparsely distributed in the horn of Africa. Their range includes southern and
southeastern Ethiopia, southern Somalia and northern Kenya. They may also be found
into northeastern Tanzania, based on an uncertain sighting in Mkomazi, Tanzania.
Habitat
Ethiopian dwarf mongooses are found in savannahs, woodlands, brush country and mountain
scrub, from sea level to elevations of about 1,800 meters. In Ethiopia, this species
is restricted to a zone of scrubby deciduous woodland made up of acacias and various
other trees. Like
common dwarf mongooses
, Ethiopian dwarf mongooses like areas with rocky outcrops or termite mounds and often
den in such areas. Ethiopian dwarf mongooses can also live in agricultural areas near
people and occur in villages where they can be quite tame.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- savanna or grassland
- scrub forest
- Other Habitat Features
- agricultural
Physical Description
Ethiopian dwarf mongooses have a head and body length of 18 to 26 cm and a tail length
of 12 to 20 cm. Compared to
common dwarf mongooses
, their fur is shaggier. Their fur color varies; generally it is finely grizzled and
grayish with yellowish-red under parts. Ethiopian dwarf mongooses typically weigh
about 200 to 350 g. The main characteristic used to differentiate Ethiopian dwarf
mongooses from
common dwarf mongooses
is the length of their upper premolars, which exceed 4.5 mm.
- Other Physical Features
- endothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
A pack of Ethiopian dwarf mongooses may contain up to 40 members, including an alpha
pair, which are typically the only members allowed to mate and raise offspring. When
alpha females start their estrous cycle, they copulate repeatedly with alpha males,
who chase off or attack interested subordinate males. These animals are considered
monogamous, but they also have polygynandrous traits. Alpha males will mate with subordinate
females and high ranking males will mate with alpha females. Ethiopian dwarf mongooses
are cooperative breeders. In fact, alpha females only suckle their own young; most
of the offspring are reared by subordinate females.
- Mating System
- monogamous
- polygynandrous (promiscuous)
- cooperative breeder
Alpha females can give birth at regular intervals, although births usually occur 3
times a year. However, if their young die, females may mate again and have the potential
to produce up to 5 litters in a year. These animals generally mate from October to
May and produce litters of 1 to 7 young after a 49 to 56 day gestation period. Other
females come into estrous around the same time, although subordinates are not allowed
to raise young of their own and alpha females usually suppress breeding among the
other females. Ethiopian dwarf mongooses often wean their young within about 45 days,
but they are typically not independent before 6 months.
- Key Reproductive Features
- seasonal breeding
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
Alpha females and males play little role in rearing the young, instead subordinates
do most of the rearing. Alpha females only allow young to suckle until they are weaned,
whereas subordinates hunt and bring food for the young until they are old enough to
hunt for themselves. Subordinate females may also suckle the young.
- Parental Investment
- female parental care
Lifespan/Longevity
Behavior
Ethiopian dwarf mongooses are extremely social and live in groups of up to 40 individuals.
Each group is thought to occupy a home range of approximately 0.3 km2 (75 acres).
According to Kingdon (1988), they occupy a certain section of their home range for
a 2 to 3 month period, then move to another part of their territory and let their
food resources replenish. Each pack defends their territory rigorously, sometimes
violently. Outsiders can be accepted but they start at the bottom of the hierarchy
and are bullied by the others. These animals are diurnal and seek shelter at night
inside termite mounds, dens or rock crevices.
- Key Behaviors
- diurnal
- motile
- territorial
- social
- colonial
- dominance hierarchies
Home Range
Packs of Ethiopian mongooses typically have home ranges of 0.3 km2 (75 acres), usually
encompassing multiple termite mounds or rocky crevices.
Communication and Perception
Vocalizations are very important for these highly social mongooses. When playing,
they use calls in the form of 'peeps', to stimulate play. A series of chirps indicate
excitement. When a predator, like a large snake or bird of prey is sighted, they make
a series of alarm calls in the form of 'tchee' and 'tchrr', this alerts the group
of danger. Ethiopian dwarf mongooses also use various other vocalizations; most activities
have a unique call associated with them. Like other mongooses, chemical cues and body
language are also important mechanisms for communication. Mongooses have well-developed
anal and facial scent glands. When marking, they often stand on their forelimbs and
apply secretions to conspecifics and landmarks throughout their territory. Social
grooming is also important; these animals groom inaccessible areas for each other,
such as the neck. Areas that are accessible, such as limbs and underparts, are groomed
by the individual. Mongooses soliciting grooming spread their legs and drag their
belly on the ground.
- Other Communication Modes
- scent marks
Food Habits
Ethiopian dwarf mongooses hunt both cooperatively and individually. These mongooses
have a very generalized carnivorous diet that includes
insects
and their larvae,
scorpions
,
myriapods
,
spiders
,
worms
,
slugs and snails
,
frogs
,
rodents
,
birds
, eggs, small
lizards
and
snakes
. When foraging for larvae and insects, they tear open decayed wood and earth by repetitive
scratching, using olfaction and hearing to determine the prey's position. Prey that
try to escape are quickly caught and killed, with efficient bites to the head. Slower
animals, like
millipedes
,
slugs and snails
are eaten alive. When consuming invertebrates, these mongooses eat all but the hardest
parts of the prey. Small birds and mammals usually are partially skinned or plucked
before consumption. Most mongoose species break eggs on hard surfaces by grasping
it with their forepaws and throwing it at a hard surface, usually a rock or tree stump.
However, Ethiopian dwarf mongooses usually exert the force with their back legs; these
animals grab the egg with their hind legs and jump up, landing on their forepaws,
throwing the egg. These small mongooses are also experts at capturing flying insects.
When Ethiopian dwarf mongooses come across flying insects; they jump into the air
and snag the insect with their forepaws or their mouth. When attacking a large food
source, such as a rat or snake, these mongooses hunt as a team to overpower the animal.
Large animals such as rats are shared by all members of the pack. According to Kingdon
(1988), these mongooses virtually wipe out rat populations around villages and farmlands
by finding rat nests and consuming the young and adults. The result was increased
crop yield and more revenue for farmers and villagers. However, these mongooses were
also keen on stealing poultry eggs.
- Primary Diet
-
carnivore
- eats terrestrial vertebrates
- eats eggs
- insectivore
- eats non-insect arthropods
- Animal Foods
- birds
- mammals
- amphibians
- reptiles
- eggs
- insects
- terrestrial non-insect arthropods
- terrestrial worms
- Plant Foods
- fruit
Predation
These small mongooses are hunted by large snakes and birds of prey. In order to avoid
predation, each individual takes a turn keeping watch over the group. The sentinel
is stationed either on a rock or tree and scouts the area while the group forages.
When a predator, such as a hawk, is spotted, an alarm call is sounded and the whole
group runs for cover.
Ecosystem Roles
Ground hornbills
have a mutualistic relationship with Ethiopian dwarf mongooses. Mongooses stir up
insects while they forage and hornbills pounce on the insects that escape. In return,
ground hornbills
alert mongooses of danger by sounding an alarm call. Ethiopian dwarf mongooses also
play a role in controlling insect and small vertebrate populations.
- Ground Hornbills ( Bucorvus )
Economic Importance for Humans: Positive
This species is economically important due to their control of pest populations. Around
farms and villages rat populations get suppressed where a large pack of mongooses
reside. They actively raid nests, killing the adults and young. Humans also eat these
small mongooses in parts of their range.
- Positive Impacts
- food
- controls pest population
Economic Importance for Humans: Negative
Ethiopian dwarf mongooses raid poultry eggs, causing farmers to lose money.
Conservation Status
Ethiopian dwarf mongooses are currently listed as a species of least concern according
to the IUCN Red List of Threatened Species.
Additional Links
Contributors
Mitchell Dybas (author), Northern Michigan University, John Bruggink (editor), Northern Michigan University.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- 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.
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- agricultural
-
living in landscapes dominated by human agriculture.
- monogamous
-
Having one mate at a time.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- cooperative breeder
-
helpers provide assistance in raising young that are not their own
- seasonal breeding
-
breeding is confined to a particular season
- 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.
- female parental care
-
parental care is carried out by females
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- territorial
-
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- social
-
associates with others of its species; forms social groups.
- colonial
-
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
- dominance hierarchies
-
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- 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
- food
-
A substance that provides both nutrients and energy to a living thing.
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- 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.
References
African Wildlife Foundation, 2013. "Dwarf Mongoose" (On-line). African Wildlife Foundation. Accessed February 20, 2013 at http://www.awf.org/wildlife-conservation/dwarf-mongoose .
Kingdon, J., J. VanRompaey, M. Hoffman. 2008. " Helogale hirtula " (On-line). IUCN Red List of Threatened Species. Accessed January 29, 2013 at http://www.iucnredlist.org/details/41608/0 .
Kingdon, J. 1988. East African Mammals: An Atlas of Evolution in Africa, Volume 3, Part A: Carnivores . Chicago: University of Chicago Press.
Nowak, R. 2004. Walkers Carnivores of the World . Baltimore: JHU Press.
Oregon Zoo, 2013. "Dwarf Mongoose" (On-line). Accessed January 31, 2013 at http://oregonzoo.org/discover/animals/dwarf-mongoose .
Rood, J. 1987. Mating relationships and Sexual Suppression of Dwarf Mongoose. Advances in the Study of Behavior , 28/1: 143-150.
Rosenblatt, J. 1987. Advances In the Study of Behavior . Waltham Massachusetts: Academic Press.
Schreiber, A., M. Riffel, H. Rompaey, R. Wirth. 1989. Weasels, Civets, Mongooses and their Relatives. An Action Plan for the Conservation of Mustelids and Viverrids , volume 3/ Issue 26: 1-106.
Veron, G., M. Colyn, A. Dunham, P. Taylor, P. Gaubert. 1980. Molecular systematics and origin of sociality in mongooses ( Herpestidae , Carnivora ). Molecular Phylogenetics and Evolution , Volume 30/ issue 3: 582-598.