Canis simensis, Ruppell, 1835

Don E. Wilson & Russell A. Mittermeier, 2009, Canidae, Handbook of the Mammals of the World – Volume 1 Carnivores, Barcelona: Lynx Edicions, pp. 352-446 : 416-417

4.

Ethiopian Wolf

Canis simensis

French: Loup d'Abyssinie / German: Athiopien-Wolf / Spanish: Lobo etiope

Other common names: Simien Fox, Simien Jackal, Abyssinian Wolf, Abyssinian Red Fox

Taxonomy. Canis simensis Ruppell, 1835 ,

Ethiopia.

Originally placed in the genus Simenia, C. simensis was noted to be the most distinct species in the genus Canis , and was considered to bear close affinity to C. adustus and Dusicyon spp. The Ethiopian Wolf is not closely linked to the Vulpes group, despite having been called the Simien or Simenian Fox. Its other name of Simien or Ethiopian Jackal suggests a close relationship with jackals. Other, previously used vernacular names included Abyssinian Wolf and Red Fox, making clear the difficulty naturalists had in cataloguing this species. Phylogenetic analysis using mitochondrial DNA sequencing suggested that C. simensis is more closely related to C. lupus and C. latrans than to any African canid, and that the species may have evolved from a Wolf-like ancestor crossing to northern Africa from Eurasia as recently as 100,000 years ago. There are fossils of wolf-like canids from the late Pleistocene in Eurasia, but unfortunately no fossil record of C. simensis itself. Microsatellite and mitochondrial DNA variability in C. simensis is small relative to other canid species, suggesting small population sizes may have characterized its recent evolution. Two subspecies are recognized.

Subspecies and Distribution.

C. s. stmensis Ruppell, 1835 — NW of Ethiopia’s Rift Valley.

C. s. citernii de Beaux, 1922 — SE of Ethiopia’s Rift Valley.

Descriptive notes. Head-body 92-8-101- 2 cm for males and 84- 1-96 cm for females, tail 29-39- 6 cm for males and 27-29- 7 cm for females; weight 14-2-19- 3 kg for males and 11-2-14- 2 kg for females. A medium-sized canid with a reddish coat, distinctive white markings, long legs, and an elongated muzzle, resembling a Coyote in conformation and size. Males weigh 20% more than females. The face, ears and upper parts of the muzzle are red. Ears broad, pointed, and directed forward; the pinnae are thickly fringed with long white hairs growing inward from the edge. Palate, gums, and naked borders of the lips entirely black. Characteristic facial markings include a white ascending crescent below the eyes, and a small white spot on the cheeks. The throat, chest, and underparts are white, the ventral part of the neck with a distinctive white band. Pelage is soft and short, ocher to rusty red, with a dense whitish to pale ginger underfur. The boundary between the red coat and the white markings is sharp and well defined. The contrast of white markings against the red coat increases with age and social rank in both sexes; the female’s coat is generally paler than the male’s. The long, slender legs are reddish outside, with inner aspect white. There is a short rufouscolored stripe at the base of the tail, which becomes a black stripe leading to a thick brush of black-tipped guard hairs. The skull is very flat in profile, with only a shallow angle between frontals and nasals. The neuro-cranium is low and narrow, thick, and almost cylindrical. Its width is 30% of the total skull length. Facial length is 58% ofthe total skull length. The inter-parietal crest is slightly developed, and the coronal ridge is linear. Teeth small and widely spaced, especially the premolars. The dental formula is13/3,C1/1,PM 4/4, M 2/3 = 42; m3 occasionally absent. Sharply pointed canines average 19 mm in length (14-22 mm); carnassials (P* and M,) are relatively small.

Habitat. A very localized endemic species, confined to isolated pockets of Afro-alpine grasslands and heath lands, where they prey on Afro-alpine rodents. Suitable habitats are above the tree-line, from about 3200 to 4500 m, with some wolves present in montane grasslands at 3000 m. However, subsistence agriculture extends up to 3500-3800 m in many areas, restricting the wolves to higher ranges. Rainfall at high altitude varies between 1000 and 2000 mm /year, with one pronounced dry period from December to February/March. Wolves utilize all Afro-alpine habitats, but prefer open areas with short herbaceous and grassland communities where rodents are most abundant, along flat or gently sloping areas with deep soils and poor drainage in parts. Prime habitats in the Bale Mountains are characterized by short herbs (Alchemilla spp.) and grasses, and low vegetation cover, a community maintained in continuous succession as a result of Ethiopian African Mole Rat (Tachyoryctes macrocephalus) burrowing activity. Other good habitats include tussock grasslands (Festuca spp., Agrostis spp.), high-altitude shrubs dominated by Helichrysum spp., and short grasslands in shallow soils. In northern parts of the range, plant communities characterized by a matrix of “guassa” tussock grasses (Festuca spp.), “cherenfi” bushes (Euryops pinifolius) and giant lobelias (Lobelia rhynchopetalum) sustain high rodent abundance and are preferred by wolves. Ericaceous moorlands (Erica and Phillipia spp.) at 3200-3600 m are of marginal value, whereas open moorlands containing patches of herbs and grasses offer relatively good habitat.

Food and Feeding. Ethiopian Wolves feed almost exclusively upon diurnal rodents of the high-altitude Afro-alpine grassland community. In the Bale Mountains, diurnal rodents accounted for 96% of all prey occurrences in feces, with 87% belonging to three Bale endemic species: the Ethiopian African Mole Rat (300-930 g), Blick’s Grass Rat ( Arvicanthis blicki ), and the Black-clawed Brush-furred Rat ( Lophuromys melanonyx ). Other prey species include the Ethiopian Vlei Rat ( Otomys typus), Ethiopian Buff-spotted Brush-furred Rat ( Lophuromys flavopunctatus ), Ethiopian Highland Hare (Lepus starcki), and occasionally goslings and eggs. On occasion, wolves were observed feeding on Rock Hyrax (Procavia capensis), and young of Bush Duiker (Sylvicapra grimmia), Common Reedbuck (Redunca redunca), and Mountain Nyala (Tragelaphus buxtoni). Sedge leaves (Carex monostachya) are occasionally ingested, probably to assist digestion or control parasites. Where the Ethiopian African Mole Ratis absent (i.e. Gaysay montane grassland in Bale and Menz), it is replaced in the wolf diet by the smaller Northeast African Mole Rat (Tachyoryctes splendens). Similarly, in northern Ethiopia Arvicanthis abyssinicus and Lophuromysflavopunctatus replace their respective endemic relatives (A. blickiand L. melanonyx) from Bale. Elsewhere, O. typus, a rare prey item in Bale and Menz, was identified as the commonest prey in droppings collected in the otherfive populations. The same study confirmed that wolves are specialized hunters of diurnal rodents throughout their distribution, but that there is also some degree of variation in diet composition along climatic-induced gradients. Although the Ethiopian Wolfis primarily a solitary rodent hunter, it can also hunt cooperatively. Occasionally, small packs have been seen chasing young antelopes, lambs, and hares and making kills. Ethiopian Wolves will take carrion or feed on carcasses; in fact, a sheep carcass is the most successful bait for attracting wolves. The local name “jedalla farda”—the horse’s Jjackal—refers to wolves’ habit of following mares and cows about to give birth so they can eat the afterbirth. In areas of grazing in Bale, wolves were often seen foraging among herds ofcattle, a tactic that may aid in ambushing rodents out oftheir holes, by using the herd as a mobile hide. Wolves carefully explore rich food patches by walking slowly and pausing frequently to investigate holes or to localize the rodents by means of their excellent hearing. Once the prey is located they move with short, stealthy steps alternating with short periods of immobility, sometimes with belly pressed flat to the ground. The quarry is grabbed with the mouth after a short dash. A stalk can last from seconds to up to an hour, especially if the quarry is an Ethiopian African Mole Rat. Occasionally, wolves run in zig-zag through rat colonies, grabbing the rodents in passing. Digging prey out is common and is the favored technique to catch Ethiopian African Mole Rats. In such cases, hunting effort varies from a few scratches at a rat hole to the total destruction of a set of burrows, leaving mounds of earth often up to one meter high. Sometimes, digging serves to reach a nest of grassrats. Kills are often cached and later retrieved.

Activity patterns. In Bale, wolves are mostly diurnal. Packs congregate for social greetings and border patrols at dawn, around midday and in the evening, and rest together at night, but break up to forage individually in the morning and early afternoon. Peaks of foraging activity suggest a synchronization with the aboveground activity of rodents. There is little nocturnal activity, wolves seldom moving far from their evening resting site. They may become more crepuscular and nocturnal where human interference 1s severe.

Movements, Home range and Social organization. Ethiopian Wolves live in packs of 3- 13 adults, in discrete and cohesive social units that share and defend an exclusive territory. Annual home ranges of eight packs monitored for four years averaged 6 km? with some overlap. Home ranges in an area of lower prey biomass averaged 13- 4 km? (n = 4). Overlap and aggressive encounters between packs were highest during the mating season. Dispersal movements are tightly constrained by the scarcity ofsuitable habitat. Males do not disperse and are recruited into multi-male philopatric packs; some females disperse at two years of age and become “floaters”, occupying narrow ranges between pack territories until a breeding vacancy becomes available. Breeding females are typically replaced after death by a resident daughter. Pack adult sex ratio is biased toward males 1-8:1, with small family groups closer to 1:1. Wolves commonly advertize and maintain their territories by scent marking territory boundaries with urine posts, scratching, feces (deposited on conspicuoussites like mounds, rocks, and bushes), and by means of vocalizations. All pack members, independent of social rank, regularly scent-mark objects along territory boundaries with raised-leg urinations and scratches. Aggressive interactions with neighboring packs are common, highly vocal, and always end with the smaller group fleeing from the larger. Vocalizations can be grouped into two categories: alarm calls, given at the scent or sight of humans, dogs, or unfamiliar wolves; and greeting calls, given at the reunion of pack members and to advertize pack size, composition, and position. Alarm calls start with a “huff” (rapid expulsion of air through mouth and nose), followed by a quick succession of highpitched yelps and barks. These sounds can also be made as contact calls, and often attract nearby pack mates. Greeting calls include a threatening growl, a high-frequency whine of submission, and intense “group yip-howls”. Lone and group howling are long-distance calls used to contact pack members, and can be heard up to 5 km away. Howling by one pack of wolves may stimulate howling in adjacent packs. Communal calls muster pack members before a border patrol.

Breeding. The only detailed information available on the reproductive habits of these animals comes from four years of observations of nine wild packs in the Bale Mountains. Pre-copulatory behavior by the dominant female includes an increased rate of scent marking, play-inducing and food-begging behavior towards the dominant male, and agonistic behavior towards subordinate females. The receptive period is synchronized in sympatric females to less than two weeks. Courtship may take place between adult members of a pack or with members of neighboring packs. After a brief courtship, which primarily involves the dominant male permanently accompanying the female, wolves copulate over a period of three to five days. Copulation involves a copulatory tie lasting up to 15 minutes. Other males may stand by a tied pair with no signs of aggression. Females exert mate preference, discouraging mating attempts from all but the pack’s dominant male, either by defensive snarls or moving away. Females are receptive to any visiting male from neighboring packs, and one study found that 70% of matings (n = 30) involved males from outside the pack. The dominant female of each pack gives birth once a year between October and January. Only about 60% of females breed successfully each year. During breeding and pregnancy, the female coat turns pale yellow and becomes woolly, and the tail turns brownish, and loses much ofits hair. Gestation lasts 60-62 days (based on the time from last day of mating to parturition). Pups are born in a den dug by the female in open ground, under a boulder or inside a rocky crevice. Neonates are born with their eyes closed. The natal coat is charcoal gray with a buff patch in chest and inguinal regions. Two to seven pups emerge from the den after three weeks. At this time, the dark natal coat begins to be replaced by the pelage typical of the species. Pups are regularly moved between dens up to 1300 m apart. In eight out of 18 observed natal dens, a subordinate female assisted the mother in suckling the pups. At least 50% of extra nursing females showed signs of pregnancy and may have lost or deserted their own offspring before joining the dominant female’s den. Five and six placental scars were counted in the uteri of two of these females. Development of the young takes place in three stages: early nesting (weeks 1-4), when the young are entirely dependent on milk; mixed nutritional dependency (weeks 5-10), when milk is supplemented by solid foods regurgitated by all pack members until pups are completely weaned; and postweaning dependency (week ten to six months), when the pups subsist almost entirely on solid foods supplied by helpers. Adults have been observed providing food to juveniles up to one year old. Juveniles join adults in patrols as early as six months of age, but do not urinate with a raised leg until eleven months, if male, or 18 months, if female. Yearlings attain 80-90% of adult body mass, and full adult appearance is reached at two years. Both sexes become sexually mature during their second year.

Status and Conservation. CITES not listed. Classified as Endangered on The IUCN Red List. Full official protection under Ethiopia’s Wildlife Conservation Regulations of 1974, Schedule VI. Killing a wolf carries a sentence of imprisonment for up to two years. There is an estimated global population of 500 adults, of which more than half live in the Bale Mountains, where wolf density is high for a social carnivore ofits size, ranging from 0- 1 adults /km® (ericaceous heath lands and barren peaks) to 1-1- 2 adults /km? (short Afro-alpine herbaceous communities). Elsewhere overall wolf density is lower; e.g. transect data from the region of Menz estimated wolf density at 0-2 animals per km?*. Recent comprehensive surveys indicate high abundance figures in North Wollo (0-20 sightings per km), intermediate in Arsi and Guna (0-10-0-11 and 0-10-0-14, respectively), and lower in South Wollo and Simien (0-08-0-13 and 0-06— 0-11, respectively). These results were supported by counts of wolf signs (diggings and droppings) and interviews with local residents. Continuous loss of habitat due to highaltitude subsistence agriculture is the major threat. Sixty percent of all land above 3200 m has been converted into farmland, and all wolf populations below 3700 m are particularly vulnerable to further habitat loss, especially in small and relatively flat areas. Habitat loss is exacerbated by overgrazing of highland pastures by domestic livestock, and in some areas habitat is threatened by proposed development of commercial sheep farms and roads. Human persecution triggered in the past by political instability is currently less severe and is associated with conflicts over livestock losses. Recent wolf population decline in Bale is mostly due to disease epizootics, with road kills and shootings as secondary threats. Rabies is a potential threatto all populations. Most of these threats are exacerbated by the wolves’ specialization to life in the Afroalpine ecosystem. In Bale, the Ethiopian Wolf hybridizes with domestic dogs. Although hybrids are currently confined to the Web Valley in West Bale, they may threaten the genetic integrity of the wolf population. Following hybridization, a population may be affected by outbreeding depression or reduction in fitness, although to date this does not seem to have taken place in Bale. To date there is no indication of hybridization taking place outside West Bale.

Bibliography. Ashenafi et al. (2005), Clutton-Brock et al. (1976), Gottelli & Sillero-Zubiri (1992), Gottelli, Marino et al. (2004), Gottelli, Sillero-Zubiri et al. (1994), Haydon, Laurenson & Sillero-Zubiri (2002), Haydon, Randall et al. (2006), Marino (2003, 2004), Marino et al. (2006), Sillero-Zubiri & Gottelli (1994, 1995a, 1995b), Sillero-Zubiri & Macdonald (1997, 1998), Sillero-Zubiri & Marino (2004), Sillero-Zubiri, Gottelli & Macdonald (1996), Sillero-Zubiri, Johnson & Macdonald (1998), Sillero-Zubiri, King & Macdonald (1996), Sillero-Zubiri, Malcolm et al. (2000), Sillero-Zubiri, Tattersall & Macdonald (1995a, 1995b).

Figures

2. Red Wolf (Canis rufus), 3. Coyote (Canis latrans), 4. Ethiopian Wolf (Canis simensis), 5. Golden Jackal (Canis aureus), 6. Side-striped Jackal (Canis adustus), 7. Black-backed Jackal (Canis mesomelas)

Subspecies and Distribution. C. s. stmensis Ruppell, 1835 — NW of Ethiopia’s Rift Valley. C. s. citernii de Beaux, 1922 — SE of Ethiopia’s Rift Valley.