Dwarf Mongoose Facts: A Small and Very Social Carnivore
A Small and Very Social Animal
The little animal known as the dwarf mongoose is the smallest carnivore in Africa. Its body is only seven to eleven inches long, not including the tail, and it weighs between seven and thirteen ounces. The animal is very social and lives in a group led by the dominant female. Its days are filled with social activities, hunting for food, and avoiding predators.
Around thirty species with the word "mongoose" in their name exist. In the wild, they live in Africa, Asia, and the Iberian Peninsula of Europe. They have been introduced to other areas. The dwarf mongoose is the smallest species. It lives only in Africa and has the scientific name Helogale parvula.
Mongoose terminology is sometimes confusing. The plural of mongoose is generally said to be mongooses, but occasionally the word mongeese is used instead. A group of mongooses may be called a mongaggle.
Physical Features, Range, and Habitat
The common dwarf mongoose (as it's sometimes called) has a pointed face, small eyes, small and rounded ears, and a domed forehead. Its body is long and has short legs and a long tail. The animal's fur is thick and varies in colour. The coat is generally brown or grey-brown and often has a grizzled appearance. Some individuals have red-brown areas on their body.
Dwarf mongooses have a wide range. They live in east Africa and the southern part of central Africa. The animals are found on grassland and in areas with scattered bushes or trees. They avoid dense forests, deserts, and elevations higher than about 2000 metres.
Mongooses are not rodents, as is sometimes thought. They belong to the class Mammalia, the order Carnivora, and the family Herpestidae, which also includes civets and meerkats.
The Social Group
Dwarf mongoose groups range in size from as few as two to as many as thirty individuals. The most common group size is twelve to fifteen animals. Most of the animals in a group are related, although sometimes outsiders are able to join them. Females tend to stay with their birth group. Males may try to join new groups once they are two or three years old. The dominant female is the only animal that reproduces.
The mongooses inhabit grassland, bush land, and open forest, where they maintain a territory. This is at least seventy-five acres in size and may be much larger. Some groups have established territories next to human settlements and have become quite confident around people.
Dwarf Mongoose Territory
During the day, the mongooses feed and socialize in their territory. At night, they usually sleep in a termite mound. Even though they are territorial, the animals lead a nomadic life within the territory. They move from one termite mound to another, generally spending only a few days in each one. There may be as many as twenty mounds in the territory. Sometimes the group spends the night in a rock that has lots of crevices or in a hollow tree instead of in a termite mound.
The animals mark their territory with scent secretions from their anal glands. Individuals may sometimes do handstands in order to mark areas that are hard to reach from ground level. They set up latrines where they deposit their urine and feces. The creation of the latrines is another way to indicate ownership of the territory.
The day begins with sunbathing and social activity, including play and mutual grooming. Mongooses nibble each other's fur with their incisors as they groom. They also mark each other with scent secretions, a procedure known as allomarking. These behaviours serve to reinforce the social bonds between individuals. Eventually, the animals are ready to begin their search for food.
Hunting for Food
Dwarf mongooses eat a variety of insects, including termites, beetles, locusts, and grubs. They also catch spiders, small rodents, birds, and reptiles. Although their diet consists mainly of other animals and they are classified as carnivores, the mongooses do eat some fruit. As they hunt and forage, they emit a chirruping call to keep in touch with other members of the group.
Since the animals are small and hunt in the daylight, they are at risk of being caught by birds of prey flying overhead and by large snakes on the ground. The mongooses take turns acting as a sentinel, perching on a rock or tree to watch for predators while the rest of the group searches for food. The sentinel gives an alarm call if he or she detects danger so that the group can hide.
A Reward for Sentinel Duty
Biologists at the University of Bristol in the UK have made some interesting discoveries about the social life of Helogale parvula. The scientists have studied a group of dwarf mongooses in South Africa since 2011. The group consists of multiple colonies. The animals in the colonies live a natural life but have become habituated to the presence of the researchers. They are free-living and are classified as wild animals. They have been trained to get on a scale so that they can be weighed and they allow researchers to approach them within a few feet, however.
The scientists have found that the group rewards those animals that have helped the community in some way. Animals that have performed a lot of sentinel duty receive extra grooming from the group members. The increased grooming doesn't necessarily happen immediately after sentinel duty has finished but usually takes place at the end of the day when the animals have returned to their sleeping area.
The researchers demonstrated that their discovery was true by playing a recording of a subordinate member's surveillance calls to a colony. The calls indicate that an animal has surveyed the surroundings. The scientist found that on days when an animal was believed to have performed more guard duties, it was given more attention at the end of the day.
What the new research shows is that mongooses have sufficient cognitive ability to quantify earlier acts of cooperation and to provide suitable levels of delayed rewards.— University of Bristol (with respect to the dwarf mongoose)
Immigration in Dwarf Mongoose Colonies
The University of Bristol researchers have also studied the fate of immigrants entering a colony. At first, an immigrant rarely serves as a sentinel, so it apparently isn't perceived as an important member of the colony. Even when it does perform an action that may help other animals, it's ignored. Within five months, however, immigrants have become completely integrated into the community and seem to be valued members of the group.
One of the researchers says that the lack of cooperation in recent immigrants is probably due in part to their weakened state. Life outside a colony is hard for a dwarf mongoose. Another factor that may delay full integration into the colony is that the mongooses don't appear to trust a newcomer's surveillance calls.
Recent immigrants are typically exhausted and run down, as evidenced by a loss of weight. Even if they tried, they couldn't contribute fully at first because other members don't yet know them.— Julie Kern, University of Bristol
In biology, a relationship between two species that is beneficial for both of them is known as mutualism. Dwarf mongooses and hornbills both benefit from their relationship.
Mongooses and Hornbills
In some parts of their range, dwarf mongooses have an interesting and mutually beneficial relationship with several species of hornbill. As the mongooses search for food, they disturb insects in the ground, which the hornbills eat. The hornbills make noisy calls when birds of prey approach, acting as an additional warning system for the mongooses so that they can run for cover.
The relationship between the mammal and the bird is finely tuned. The hornbills wait in the trees near the termite mound where the mongooses are sleeping so that the two species can hunt together. If the hornbills are absent for some reason, the mongooses delay their hunting expedition until the birds arrive.
Even though the females in a dwarf mongoose colony may all come into estrus (a state in which they are receptive to a male) at the same time, only the dominant female produces babies. She is the head of the colony. Her mate occupies the second highest rank in the group. The phenomenon in which only the dominant female in a community reproduces is known as reproductive suppression.
The subordinate females may mate, but they rarely give birth. It's not certain why a subordinate female is unable to reproduce. Suggestions have included the inability of the egg and sperm to join inside the female's body or the death of the embryos at an early stage of development. If subordinate females do give birth, the babies soon disappear. This may be because the babies are too weak to survive or because they are killed by the dominant female.
Caring for the Pups
A dominant female gives birth to three or four litters a year after a gestation period of around fifty-three days. A litter contains two to four pups. The entire dwarf mongoose group is interested in the pups.
The mother suckles the young but seems to have little else to do with them. The other females and the males in the group take turns babysitting the pups, grooming and cleaning them, protecting them from danger, carrying them around, playing with them, and bringing them food. Occasionally, a subordinate female will nurse the youngsters. Dwarf mongooses live for about eight years.
Unlike some of the animals that I write about, the dwarf mongoose isn't endangered. As is the case with other animal populations, however, it's important to watch for any problems. Many animal species around the world are in trouble, often due to human activity.
Population Status of Dwarf Mongooses
The IUCN (International Union for Conservation of Nature) has placed the dwarf mongoose in the "Least Concern" category of its Red List. This list classifies animals according to their nearness to extinction. At the moment, the mongoose population is doing well.
Despite their Red List classification, I don't think we should become complacent about the status of the animal. They are eaten by humans in some parts of Africa. In areas near human habitation, the mongoose is sometimes killed because of its interest in chicken eggs.
Zoos in the Association of Zoos and Aquariums (AZA) follow the dwarf mongoose survival plan® and cooperate in their efforts to save the species. AZA is a nonprofit organization whose goals are to promote wildlife conservation, the welfare of animals in captivity, and education of the public.
Observing the Animals
Dwarf mongooses are entertaining animals to watch as they scamper around and interact with their companions. They are lively and inquisitive creatures that are present in several zoos. This makes it easier for the general public to see them, since most people are unable to make a trip to Africa to see the animals in their natural habitat.
Zoos are often controversial institutions. The bad ones shouldn't exist. The better ones try to provide a good environment and life for their charges. These zoos can be educational for the public and helpful in the effort to breed endangered animals. Life in the wild instead of in captivity is best for dwarf mongooses and enables them to perform natural behaviours. Zoo observations can be very enjoyable for visitors and a great learning experience, however. The animals are interesting to observe.
- Dwarf mongoose from Smithsonian's National Zoo and Conservation Biology Institute
- Information about dwarf mongooses from the San Diego Zoo
- Facts about Helogale parvula from the Oregon Zoo
- Dwarf mongooses remember and reward helpful friends from the University of Bristol
- Immigrants become part of the group from phys.org news service
- The Helogale parvula entry on the IUCN Red List
Questions & Answers
© 2012 Linda Crampton