Ethiopian wolf

Appearance

The Ethiopian wolf is similar in size and build to North America's coyote; it is larger than the black-backed jackal and side-striped jackals as well as the African wolf and has comparatively longer legs. Its skull is very flat, with a long facial region accounting for 58% of the skull's total length. The ears are broad, pointed, and directed forward. The teeth, particularly the premolars, are small and widely spaced. The canine teeth measure 14–22 mm in length, while the carnassials are relatively small. The Ethiopian wolf has eight mammae, of which only six are functional. The front paws have five toes, including a dewclaw, while the hind paws have four. As is typical in the genus "Canis", males are larger than females, having 20% greater body mass. Adults measure 841–1,012 mm in body length, and 530–620 mm in height. Adult males weigh 14.2–19.3 kg, while females weigh 11.2–14.15 kg.

The Ethiopian wolf has short guard hairs and thick underfur, which provides protection at temperatures as low as −15 °C. Its overall colour is ochre to rusty red, with dense whitish to pale ginger underfur. The fur of the throat, chest and underparts is white, with a distinct white band occurring around the sides of the neck. There is a sharp boundary between the red coat and white marks. The ears are thickly furred on the edges, though naked on the inside. The naked borders of the lips, the gums and palate are black. The lips, a small spot on the cheeks and an ascending crescent below the eyes are white. The thickly furred tail is white underneath, and has a black tip, though, unlike most other canids, there is no dark patch marking the supracaudal gland. It moults during the wet season, and there is no evident seasonal variation in coat colour, though the contrast between the red coat and white markings increases with age and social rank. Females tend to have paler coats than males. During the breeding season, the female's coat turns yellow, becomes woolier, and the tail turns brownish, losing much of its hair.

Animals resulting from Ethiopian wolf-dog hybridisation tend to be more heavily built than pure wolves, and have shorter muzzles and different coat patterns.

Naming

Alternative English names for the Ethiopian wolf include the Simenian fox, the Simien jackal, Ethiopian jackal, and Abyssinian wolf.

Distribution

Six current Ethiopian wolf populations are known. North of the Rift Valley, the species occurs in the Simien Mountains in Gondar, in the northern and southern Wollo highlands, and in Guassa Menz in north Shoa. It has recently become extinct in Gosh Meda in north Shoa and Mount Guna, and has not been reported in Mount Choqa for several decades. Southeast of the Rift Valley, it occurs in the Arsi and Bale Mountains.Some Ethiopian wolf populations, particularly those in North Wollo, show signs of high fragmentation, which is likely to increase with current rates of human expansion. The dangers posed by fragmentation include increased contact with humans, dogs, and livestock, and further risk of isolation and inbreeding in wolf populations. Although no evidence of inbreeding depression or reduced fitness exists, the extremely small wolf population sizes, particularly those north of the Rift Valley, raise concerns among conservationists. Elsewhere, the Bale populations are fairly continuous, while those in Simien can still interbreed through habitat corridors.

Behavior

The Ethiopian wolf is a social animal, living in family groups containing up to 20 adults, though packs of six wolves are more common. Packs are formed by dispersing males and a few females, which with the exception of the breeding female, are reproductively suppressed. Each pack has a well-established hierarchy, with dominance and subordination displays being common. Upon dying, a breeding female can be replaced by a resident daughter, though this increases the risk of inbreeding. Such a risk is sometimes circumvented by multiple paternity and extra-pack matings. The dispersal of wolves from their packs is largely restricted by the scarcity of unoccupied habitat.

These packs live in communal territories, which encompass 6 km2 of land on average. In areas with little food, the species lives in pairs, sometimes accompanied by pups, and defends larger territories averaging 13.4 km2. In the absence of disease, Ethiopian wolf territories are largely stable, but packs can expand whenever the opportunity arises, such as when another pack disappears. The size of each territory correlates with the abundance of rodents, the number of wolves in a pack, and the survival of pups. Ethiopian wolves rest together in the open at night, and congregate for greetings and border patrols at dawn, noon, and evening. They may shelter from rain under overhanging rocks and behind boulders. The species never sleeps in dens, and only uses them for nursing pups. When patrolling their territories, Ethiopian wolves regularly scent-mark, and interact aggressively and vocally with other packs. Such confrontations typically end with the retreat of the smaller group.Unlike most social carnivores, the Ethiopian wolf tends to forage and feed on small prey alone. It is most active during the day, the time when rodents are themselves most active, though they have been observed to hunt in groups when targeting mountain nyala calves. Major Percy-Cotton described the hunting behaviour of Ethiopian wolves as thus:

... they are most amusing to watch, when hunting. The rats, which are brown, with short tails, live in big colonies and dart from burrow to burrow, while the cuberow stands motionless till one of them shows, when he makes a pounce for it. If he is unsuccessful, he seems to lose his temper, and starts digging violently; but this is only lost labour, as the ground is honeycombed with holes, and every rat is yards away before he has thrown up a pawful.

The technique described above is commonly used in hunting big-headed African mole-rats, with the level of effort varying from scratching lightly at the hole to totally destroying a set of burrows, leaving metre-high earth mounds.

Wolves in Bale have been observed to forage among cattle herds, a tactic thought to aid in ambushing rodents out of their holes by using the cattle to hide their presence. Ethiopian wolves have also been observed forming temporary associations with troops of grazing geladas. Solitary wolves hunt for rodents in the midst of the monkeys, ignoring juvenile monkeys, though these are similar in size to some of their prey. The monkeys, in turn, tolerate and largely ignore the wolves, although they take flight if they observe feral dogs, which sometimes prey on them. Within the troops, the wolves enjoy much higher success in capturing rodents than usual, perhaps because the monkeys' activities flush out the rodents, or because the presence of numerous larger animals makes it harder for rodents to spot a threat.

Habitat

The Ethiopian wolf is restricted to isolated pockets of Afroalpine grasslands and heathlands inhabited by Afroalpine rodents. Its ideal habitat extends from above the tree line around 3,200 to 4,500 m, with some wolves inhabiting the Bale Mountains being present in montane grasslands at 3,000 m. Although specimens were collected in Gojjam and northwestern Shoa at 2,500 m in the early 20th century, no recent records exist of the species occurring below 3,000 m. In modern times, subsistence agriculture, which extends up to 3,700 m, has largely restricted the species to the highest peaks.

The Ethiopian wolf uses all Afroalpine habitats, but has a preference for open areas containing short herbaceous and grassland communities inhabited by rodents, which are most abundant along flat or gently sloping areas with poor drainage and deep soils. Prime wolf habitat in the Bale Mountains consists of short "Alchemilla" herbs and grasses, with low vegetation cover. Other favourable habitats consist of tussock grasslands, high-altitude scrubs rich in "Helichrysum", and short grasslands growing in shallow soils. In its northern range, the wolf's habitat is composed of plant communities characterised by a matrix of "Festuca" tussocks, "Euryops" bushes, and giant lobelias, all of which are favoured by the wolf's rodent prey. Although marginal in importance, the ericaceous moorlands at 3,200–3,600 m in Simien may provide a refuge for wolves in highly disturbed areas.During the 1990s, wolf populations in Gosh Meda and Guguftu became extinct. In both cases, the extent of Afroalpine habitat above the limit of agriculture had been reduced to less than 20 km2. The EWCP team confirmed the extinction of a wolf population in Mt. Guna in 2011, whose numbers had been in single figures for several years. Habitat loss in the Ethiopian highlands is directly linked to agricultural expansion into Afroalpine areas. In the northern highlands, human density is among the highest in Africa, with 300 people per km2 in some localities, with almost all areas below 3,700 m having been converted into barley fields. Suitable areas of land below this limit are under some level of protection, such as Guassa-Menz and the Denkoro Reserve, or within the southern highlands, such as the Arsi and Bale Mountains. The most vulnerable wolf populations to habitat loss are those within relatively low-lying Afroalpine ranges, such as those in Aboi Gara and Delanta in North Wollo.

Reproduction

The mating season usually takes place between August and November. Courtship involves the breeding male following the female closely. The breeding female only accepts the advances of the breeding male, or males from other packs. The gestation period is 60–62 days, with pups being born between October and December. Pups are born toothless and with their eyes closed, and are covered in a charcoal-grey coat with a buff patch on the chest and abdomen. Litters consist of two to six pups, which emerge from their den after three weeks, when the dark coat is gradually replaced with the adult colouration. By the age of five weeks, the pups feed on a combination of milk and solid food, and become completely weaned off milk at the age of 10 weeks to six months. All members of the pack contribute to protecting and feeding the pups, with subordinate females sometimes assisting the dominant female by suckling them. Full growth and sexual maturity are attained at the age of two years. Cooperative breeding and pseudopregnancy have been observed in Ethiopian wolves.

Most females disperse from their natal pack at about two years of age, and some become "floaters" that may successfully immigrate into existing packs. Breeding pairs are most often unrelated to each other, suggesting that female-biased dispersal reduces inbreeding. Inbreeding is ordinarily avoided because it leads to a reduction in progeny fitness due largely to the homozygous expression of deleterious recessive alleles.

Food

Unlike most social carnivores, the Ethiopian wolf tends to forage and feed on small prey alone. It is most active during the day, the time when rodents are themselves most active, though they have been observed to hunt in groups when targeting mountain nyala calves. Major Percy-Cotton described the hunting behaviour of Ethiopian wolves as thus:

... they are most amusing to watch, when hunting. The rats, which are brown, with short tails, live in big colonies and dart from burrow to burrow, while the cuberow stands motionless till one of them shows, when he makes a pounce for it. If he is unsuccessful, he seems to lose his temper, and starts digging violently; but this is only lost labour, as the ground is honeycombed with holes, and every rat is yards away before he has thrown up a pawful.

The technique described above is commonly used in hunting big-headed African mole-rats, with the level of effort varying from scratching lightly at the hole to totally destroying a set of burrows, leaving metre-high earth mounds.

Wolves in Bale have been observed to forage among cattle herds, a tactic thought to aid in ambushing rodents out of their holes by using the cattle to hide their presence. Ethiopian wolves have also been observed forming temporary associations with troops of grazing geladas. Solitary wolves hunt for rodents in the midst of the monkeys, ignoring juvenile monkeys, though these are similar in size to some of their prey. The monkeys, in turn, tolerate and largely ignore the wolves, although they take flight if they observe feral dogs, which sometimes prey on them. Within the troops, the wolves enjoy much higher success in capturing rodents than usual, perhaps because the monkeys' activities flush out the rodents, or because the presence of numerous larger animals makes it harder for rodents to spot a threat.In the Bale Mountains, the Ethiopian wolf's primary prey are big-headed African mole-rats, though it also feeds on grass rats, black-clawed brush-furred rats, and highland hares. Other secondary prey species include vlei rats, yellow-spotted brush-furred rats, and occasionally goslings and eggs. Ethiopian wolves have twice been observed to feed on rock hyraxes, and mountain nyala calves. It will also prey on reedbuck calves. In areas where the big-headed African mole-rat is absent, the smaller Northeast African mole-rat is targeted. In the Simien Mountains, the Ethiopian wolf preys on Abyssinian grass rats. Undigested sedge leaves have occasionally been found in Ethiopian wolf stomachs. The sedge possibly is ingested for roughage or for parasite control. The species may scavenge on carcasses, but is usually displaced by free-ranging dogs and African golden wolves. It typically poses no threat to livestock, with farmers often leaving herds in wolf-inhabited areas unattended.

Predators

The Ethiopian wolf has been considered rare since it was first recorded scientifically. The species likely has always been confined to Afroalpine habitats, so it was never widespread. In historical times, all of the Ethiopian wolf's threats are both directly and indirectly human-induced, as the wolf's highland habitat, with its high annual rainfall and rich fertile soils, is ideal for agricultural activities. Its proximate threats include habitat loss and fragmentation, diseases, conflict with humans, and hybridisation with dogs.