Canis simensis: INFORMATION - ADW

Geographic Range
The Ethiopian wolf has a very restricted range. It is found only in six or seven mountain ranges of Ethiopia. This includes the Arssi and Bale mountains of southeast Ethiopia, the Simien mountains, northeast Shoa, Gojjam, and Mt. Guna (Ginsberg and Macdonald 1990). The largest population exists in the Bale Mountains National Park with 120-160 individuals (Sillero-Zubiri and Gottelli 1995).
Physical Description
Ethiopian wolves are long-limbed, slender looking canids. They have a reddish coat with white marking on the legs, underbelly, tail, face, and chin. The boundary between the red and white fur is quite distinct. White markings on the face include a characteristic white crescent below the eyes and a white spot on the cheeks. The chin and throat are also white. The tail is marked with an indistinct black stripe down its length and a brush of black hairs at the tip. The ears are wide and pointed and the nose, gums, and palate are black. Females are generally paler in color than males and are smaller overall. There are five toes on the front feet and four on the rear feet. Males measure from 928 to 1012 mm (average 963 mm) and females from 841 to 960 mm (average 919 mm). Males weigh from 14.2 to 19.3 kg (average 16.2) and females from 11.2 to 14.2 kg (average 12.8). The tail is from 270 to 396 mm in length. The dental formula is 3/3:1/1:4/4:2/3, with the lower third molar being absent occasionally. (Sillero-Zubiri and Marino, 1995)
Reproduction
For Ethiopian wolves, dispersal from their native packs is limited due to habitat saturation. Males generally remain in their natal pack, and a small number of females disperse in their second or third year. To combat this high potential for inbreeding inside the closely related pack, matings outside the pack occur frequently. Copulation outside the pack occurs with males of all rank, but those within the pack occur only between the dominant male and female. While copulation between males and subordinate females does occur, pups that may arise from this union rarely survive (Sillero-Zubiri et al. 1996).
Prior to copulation, the dominant female increases her rate of scent marking, play soliciting, food begging towards the dominant male, and aggressive behavior towards subordinate females. Ethiopian wolves mate over a period of 3-5 days, involving a copulation tie that lasts up to 15 minutes.
It is not uncommon for a subordinate female to assist in suckling the young of the dominant female. In these cases, the subordinate lactating female is likely pregnant and either loses or deserts her own young for those of the dominant female.
Once a year between October and January, the dominant female in each pack gives birth to a litter of 2-6 pups. Gestation lasts approximately 60-62 days. The female gives birth to her litter in a den she digs in open ground under a boulder or in a rocky crevice. The pups are born with their eyes closed and no teeth. They are charcoal gray with a buff patch on their chest and under areas. At about 3 weeks, the coat begins to be replaced by the normal adult coloring and the young first emerge from the den. After this time, den sites are regularly shifted, sometimes up to 1300m.
Development of the young occurs in three stages (Sillero-Zubiri and Gottelli 1994). The first covers weeks 1-4 when the pups are completely dependent on their mother for milk. The second occurs from week 5-10 from when the pups' milk diet is supplemented by solid food regurgitated from all pack members. It ends when the pups are completely weaned. Finally, from week 10 until about 6 months, the young survive almost solely on solid food provided from adult members of the pack. Adults have been seen providing food for young up to 1 year old. The Ethiopian wolf attains full adult appearance at 2 years of age, and both sexes are sexually mature during their second year (Sillero-Zubiri and Gottelli 1994). Data on life expectancy is inadequate, but C. simensis is likely to live 8-9 years in the wild (Macdonald 1984).
Lifespan/Longevity
Ethiopian wolves may live 8 to 10 years in the wild, although one wild individual was recorded living to 12 years. (Sillero-Zubiri and Marino, 1995)
Range lifespan Status: wild
12 (high) years
Typical lifespan Status: wild
10 (high) years
Behavior
Although it primarily does its hunting alone, C. simensis is a social animal, forming packs of 3-13 individuals (mean 6). Packs congregate for social greetings and border patrols at dawn, midday, and evening, but forage individually during the rest of the day. The Ethiopian wolf is diurnal and sleeps in the open during night, alone or in groups. Pack structure is hierarchical and well defined by dominant and submissive displays as seen with other canids. Each sex has a dominance rank with shifts occurring in males occasionally but not in females. Play-fighting among pups in the first few weeks begins to establish rank between siblings (Sillero-Zubiri and Gottelli 1994).
Ethiopian wolf packs are territorial. C. simensis travels in packs to patrol its territory. Packs maintain the boundaries of their territories by scent marking and vocalization. Home ranges of packs are small for a canid of its size. The typical home range is 4-15 square kilometers with an average wolf density of 1/square kilometer. Skirmishes between neighboring packs are frequent.
Canis simensis makes several types of vocalization. Alarm calls are emitted at the sight or scent of man, dogs, or unfamiliar wolves. They start with a "huff" and are followed by a series of "yelps" and "barks." Greeting calls consist of "growls" of threat, high-frequency "whines" of submission, and "group yip-howls" given at reunion of pack members. Also, "lone howls" or "group howls" can be heard 5 km away and are used for long distance communication (Sillero-Zubiri and Gottelli 1994).
Communication and Perception
Food Habits
Canis simensis is a carnivore, generally preying on rodents ranging in size from the giant mole-rat Tachyoryctes macrocephalus (900 g) to that of the common grass rats (Arvicanthis blicki, Lophuromys melanonyx; 90-120 g) (Ginsberg and Macdonald 1990). In 689 feces, murid rodents accounted for 95.8% of all prey items, and 86.6% belonged to the three species listed above (Sillero-Zubiri and Gottelli 1994). When present in the hunting range, giant mole-rats are the primary component of the diet. In its absence, the common mole-rat Tachyoryctes splendens is most commonly eaten (Malcom 1997). Canis simensis also eats goslings, eggs, and young ungulates (reedbuck and mountain nyla) and occasionally scavenges carcasses. The Ethiopian wolf often caches its prey in shallow holes (Ginsberg and Macdonald 1990).
Prey is usually captured by digging it out of burrows. Areas of high prey density are patrolled by wolves walking slowly. Once prey is located, the wolf moves stealthily towards it and grabs it with its mouth after a short dash. Occasionally, the Ethiopian wolf hunts cooperatively to bring down young antelopes, lambs, and hares (Sillero-Zubiri and Gottelli 1994).
Ecosystem Roles
Ethiopian wolves are top predators in the ecosystems in which they live.
Economic Importance for Humans: Positive
Canis simensis helps control populations of rodents in its habitat.
Economic Importance for Humans: Negative
The Ethiopian wolf occasionally preys on lambs (Sillero-Zubiri 1995).
Conservation Status
Ethiopian wolves are considered endangered by both the IUCN and U.S. Endangered Species Act. They are protected from hunting under Ethiopian law. Effort to curb the transmission of diseases, especially rabies, to Ethiopian wolves from domestic dogs and to prevent hybridization with domestic dogs have been undertaken. In addition, monitoring of Ethiopian wolf populations continues. (Sillero-Zubiri and Marino, 1995)
Other Comments
A recent genetic study suggests that the C. simensis is more closely related to gray wolves and coyotes than any other African canid (jackals, foxes, wild dogs). It is hypothesized that C. simensis is an evolutionary remnant of a past invasion of North Africa by gray wolf-life ancestors (Gottelli et al. 1994).
Contributors
Andrew Bunker (author), University of Michigan-Ann Arbor.
Glossary
Ethiopian
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
altricial
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
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
carrion
flesh of dead animals.
chemical
uses smells or other chemicals to communicate
cooperative breeder
helpers provide assistance in raising young that are not their own
crepuscular
active at dawn and dusk
diurnal
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.
monogamous
Having one mate at a time.
motile
having the capacity to move from one place to another.
mountains
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
native range
the area in which the animal is naturally found, the region in which it is endemic.
nocturnal
active during the night
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.
solitary
lives alone
stores or caches food
places a food item in a special place to be eaten later. Also called "hoarding"
tactile
uses touch to communicate
temperate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
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 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.
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This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.