Helogale hirtuladesert dwarf mongoose

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. (Kingdon, et al., 2008)

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. (Kingdon, et al., 2008; Kingdon, 1988; Nowak, 2004)

  • Range elevation
    0 to 1,800 m
    0.00 to ft

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. (Kingdon, 1988; Nowak, 2004; Oregon Zoo, 2013)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    200 to 350 g
    7.05 to 12.33 oz
  • Range length
    18 to 26 cm
    7.09 to 10.24 in

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. (Kingdon, 1988; Nowak, 2004)

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. (Nowak, 2004; Rosenblatt, 1987)

  • Breeding interval
    Ethiopian dwarf mongooses generally produce 3 litters per year, however, they may have up to 5 litters in a year.
  • Breeding season
    Ethiopian dwarf mongooses typically breed from October to May.
  • Range number of offspring
    1 to 7
  • Range gestation period
    49 to 56 days
  • Average weaning age
    45 days
  • Range time to independence
    6 (low) months
  • Average age at sexual or reproductive maturity (female)
    2 to 3 years
  • Average age at sexual or reproductive maturity (male)
    3 years

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. (Nowak, 2004)

Lifespan/Longevity

These animals have an average lifespan of about 8 years. (African Wildlife Foundation, 2013; Oregon Zoo, 2013)

  • Average lifespan
    Status: wild
    8 years

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. (Kingdon, 1988)

  • Average territory size
    0.3 km^2

Home Range

Packs of Ethiopian mongooses typically have home ranges of 0.3 km2 (75 acres), usually encompassing multiple termite mounds or rocky crevices. (Kingdon, 1988; Nowak, 2004)

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. (Kingdon, 1988)

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. (Kingdon, 1988)

  • 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. (African Wildlife Foundation, 2013)

  • Known Predators
    • birds of prey
    • large snakes

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. (Kingdon, 1988; Oregon Zoo, 2013; Schreiber, et al., 1989)

Mutualist Species

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. (Kingdon, 1988)

  • Positive Impacts
  • food
  • controls pest population

Economic Importance for Humans: Negative

Ethiopian dwarf mongooses raid poultry eggs, causing farmers to lose money. (Kingdon, 1988)

Conservation Status

Ethiopian dwarf mongooses are currently listed as a species of least concern according to the IUCN Red List of Threatened Species. (Kingdon, et al., 2008)

Contributors

Mitchell Dybas (author), Northern Michigan University, John Bruggink (editor), Northern Michigan University.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

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.

cooperative breeder

helpers provide assistance in raising young that are not their own

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

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

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.

female parental care

parental care is carried out by females

food

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

insectivore

An animal that eats mainly insects or spiders.

monogamous

Having one mate at a time.

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.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

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

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

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

tropical

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

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.

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

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.