Elephant Shrews or Sengis: Mammals With Long and Mobile Noses
A Curious Animal
An elephant shrew is a small mammal with a long, protruding nose that is constantly moving and sensing the environment. The animal is known as an "elephant" shrew because its flexible and mobile nose reminded earlier scientists of an elephant’s trunk. The projection is technically known as a proboscis. The animal has a hunchbacked posture, long, slender legs, and a scaly, mouse-like tail, giving it a curious appearance.
Elephant shrews live in Africa. They aren’t shrews, despite their name, and they aren't rodents either, despite the appearance of their tail. They are related to tenrecs, aardvarks, manatees, hyraxes, and elephants. Like these animals, they belong to a group known as the Afrotheria. Some people prefer to call elephant shrews sengis, a word that comes from the Bantu language, in order to avoid any connection to shrews.
Sengis and shrews belong to the class Mammalia, as we do. Sengis belong to the order Macroscelidea and the family Macroscelididae. Shrews belong to the order Eulipotyphla and the family Soricidae.
Types of Elephant Shrews or Sengis
According to the latest classification scheme, twenty species of elephant shrews are recognized. The number of species may change as new discoveries are made and as more genetic analyses are performed. The status of the animals may also change as a result of additional surveys and new estimates of population size.
The animals are divided into two groups. The giant elephant shrews may reach twelve inches in length, not including the tail. They often have vivid colors and weigh about a pound each. The animals in the second group are known as soft-furred elephant shrews and are much smaller. They weigh up to around seven ounces and have less colorful grey or brown coats.
Giant Elephant Shrew Species
Black and rufous
The data in the table above comes from the IUCN, or the International Union for Conservation of Nature (except for the information related to the third species, which has only recently been recognized). According to the organization, the population of the first two species and the fourth one in the table is decreasing. The population trend for the fifth species is unknown.
A New Species of Rhynchocyon
In 2017, a group of scientists from multiple institutions decided that a subspecies of the checkered elephant shrew (Rhynchocyon cirnei stuhlmanni) should be elevated to full species status (Rhynchocyon stuhlmanni). The decision brought the total number of giant elephant shrew species up to five and the total number of all elephant shrews up to twenty.
The animal of interest has a distinctive white tail and smaller nose bones than the other members of the R. cirnei species. It also has important genetic differences from the other animals. According to the first source in the "References" section below, the animal has been assigned the common name of "white-tailed sengi". Its population status is unknown at the moment.
Fifteen species of soft-furred elephant shrews are recognized at the moment. One belongs to the genus Petrodromus, three to the genus Macroscelides, and eleven to the genus Elephantulus. Some researchers believe that Elephantulus rozeti should be reclassified as Petrosaltator rozeti. Currently, the population status of most of the soft-furred elephant shrews is not a concern.
Hunting and Foraging
Sengis live in many parts of Africa in a variety of habitats. They are found in forests, scrubland, savanna, or semi-desert areas, depending on the species. Giant sengis are generally found in forests and dense woodland and are diurnal, or active during the day. The smaller animals are usually found in grassland and drier areas. They are often crepuscular, which means that they tend to be active in the early morning and late evening. Some are nocturnal, or active only at night.
Sengis have a good sense of smell and also see and hear well. They are omnivorous creatures but feed mainly on other animals. They eat a lot of insects as well as some spiders, centipedes, and millipedes. They occasionally include earthworms in their diet. Small sengis eat a significant quantity of fruit, seeds, and leaves.
A sengi roots out its prey with its long, probing proboscis. The smaller species have a shorter proboscis than the giant ones. Once food is found, the animal extends its long tongue to pick up the prey. The tongue typically flicks the food into the mouth.
The Etendeka round-eared elephant shrew (Microscelides micus) was discovered in 2006 and named in 2014. The animal has been found only near the Etendeka volcanic formation in the northwestern part of Namibia.
Some elephant shrews create trails in the leaf litter or grass. They patrol these trails regularly as they look for prey. The paths also provide a very important escape route during times of danger, as the video below shows.
The animals have powerful back legs and are capable of moving fast and jumping high relative to their size. They often move by a combined running and hopping motion, especially when they are trying to avoid a predator. They've also been observed slapping their tail against the ground or drumming their feet in times of stress.
The elephant shrews that have been studied are monogamous, which means that the same male and female pair up each time mating takes place. The pair share the same territory or occupy neighboring territories, but they have little to do with each other except during mating.
The male and female sleep in a different nest, as their shelter is called. They often create the nest by digging a hole in the ground or by using a hole created by another creature. They may also build it in a rock crevice or another protected area. The nests are generally lined by leaves.
Elephant shrews mark their territory with secretions from glands that are located in several places on their bodies, including around the anus, on the feet, under the tail, and on the chest. They detect the presence of another animal's secretions with their sense of smell. Males will drive other males away from the area and females will protect the area from other females. Encounters with invaders are often violent. Vocalizations are said to be uncommon in the animals, however.
Macroscelides proboscideus is sometimes referred to as the Karoo round-eared elephant shrew to distinguish it from other members of its genus. The Karoo is a semi-desert region in South Africa.
Elephant shrew gestation lasts for 45 to 60 days. The litters are small and consist of just one to three offspring. Giant sengis are said to have only one offspring at a time, although some researchers dispute this claim. Several litters may be born in a year. In at least some species, the babies are born in a separate nest from the mother's regular sleeping one.
The babies have mature features at birth. Their hair has formed and their eyes are open. They can move around after only a few hours. They remain hidden in the nest for about the first three weeks of their life, however. The youngsters then emerge and follow their mother around for one or two weeks. At the end of this time, they are weaned. The length of each stage in a youngster's development depends on the species.
After weaning, the youngsters stay in their mother's territory for about six more weeks before they leave to establish a territory of their own. Elephant shrews generally live for two to five years, depending on the species.
Although the elephant shrew's highly mobile proboscis is reminiscent of an elephant's trunk, it's hard to imagine that this little animal and the giant elephant are related. Researchers say that the DNA evidence supports this relationship, however.
Scientists have created a classification group called the Afrotheria. The group includes elephant shrews, elephants, and other animals. The scientists say that all of the present members of the group evolved from a common ancestor in Africa.
The Afrotheria group includes the following animals. The numbers in brackets refer to the pictures shown in the collage below.
- aardvarks (1)
- dugongs (2)
- elephant shrews or sengis (3)
- manatees or sea cows (4)
- golden moles (which are different from "true" moles) (5)
- hyraxes (6)
- elephants (7)
- tenrecs (8)
Red List Abbreviations
LC - Least Concern
NT - Near Threatened
VU - Vulnerable
EN - Endangered
CR - Critically Endangered
EW - Extinct in the Wild
EX - Extinct
A Data Deficient or DD category and a Not Evaluated or NE category are sometimes added to the Red List categories.
Population Status of Sengis
The IUCN maintains a Red List of organisms. This list contains animals and plants categorized according to their risk of becoming extinct. Most of the soft-furred elephant shrew populations are classified in the Least Concern category, but a few are categorized as Data Deficient. The latter term indicates that we don't have a good estimate for the number of animals that exist so we can't make a decision about their population status. The giant elephant shrews are classified in the Least Concern, Vulnerable, or Endangered category.
Threats to the Population
Sengis are eaten by predators such as birds of prey, snakes, and lizards. In some areas, humans kill the animals for food. The chief problem faced by giant sengis is the loss and fragmentation of their habitat, however. As trees are logged to clear land for agriculture or buildings, the amount of land available for the animals decreases.
Loss of its forest habitat seems to be the major problem for the golden-rumped sengi, which is the most endangered member of the order. The IUCN's last population estimate for the species was performed in 2013. As the quote below indicates, the organization is not convinced that the situation is improving for the animal.
Habitat loss and fragmentation are growing problems for wildlife in many parts of the world today as humans become increasingly dominant in the landscape. The term "fragmentation" means that suitable habitats for an animal are restricted to small areas that are separated from each other. Fragmentation can be dangerous for a population because it reduces the chance that unrelated males and females will meet and mate. This reduces genetic diversity and health in the population.
It is not clear what the current status of the forest habitats for this sengi are, nor are there recent accurate estimates on abundance, so we are left with the reasonable assumption that habitat and sengi population declines continue due to the various anthropogenic factors identified in the past.— IUCN (with respect to the golden-rumpled sengi)
A twenty-five year strategic management plan (2002–2027) has been established for a major Kenyan forest occupied by the golden-rumped sengi. The goal of the plan is to establish sustainable management of the forest and community participation in this action. It's unknown whether the plan has helped the sengi yet.
Conservation organizations are working to protect wildlife while also trying to meet the needs of humans. Both goals are important in our world today. Hopefully, the efforts will help sengis that are in trouble.
- Sengis (Elephant Shrews) from the California Academy of Sciences
- Classification of a new giant sengi species from the phys.org news service
- Elephant shrew information from the African Wildlife Foundation
- Black and rufous elephant shrew information from the Encyclopedia of Life
- Information about the endangered golden-rumped elephant shrew from the IUCN
- Bushveld elephant shrew facts from the IUCN
Questions & Answers
© 2011 Linda Crampton