Dogs, Wolves, Coyotes, Jackals, and Foxes (Canidae)
Dogs, wolves, coyotes, jackals, and foxes
Coat colors may be black, brown, or red; cursorial predators, they have both cutting and grinding teeth.
2.2–165 lb (1–75 kg)
Number of genera, species
14 genera; 35 species
Open and lightly wooded country for most species
Extinct: 1 species; Critically Endangered: 2 species; Endangered: 1 species; Vulnerable: 2 species; Lower Risk: 3 species; Data Deficient: 9 species
All continents except Antarctica and Australia (wild canids); domestic dogs worldwide
Evolution and systematics
Fossils show that dog-like animals, i.e., animals with legs for running and teeth to tackle a range of food including other animals, have evolved on several occasions in the last 50 million years. The exact anatomical conformation that corresponds to the canids of today appears for the first time in 10 million-year-old fossils from North America. By seven million years ago the fossil skulls were similar enough to modern species to be put in the genus Canis. It is believed that it was at about the same time that canids colonized Eurasia and Africa. Wolf-like members of the dog family are common through the fossil record and vary in size from small jackals at 15 lb (6.8 kg) to the dire wolf (Canis dirus), which probably weighed over 200 lb (90.7 kg). The latter was very common in western North America as recently as 10,000 years ago. Its stocky build and large teeth suggest that it might have been more proficient as a scavenger than as a hunter. The modern members of the wolf-like group include the wolves (but not the maned wolf [Chrysocyon brachyurus] of South America), coyotes (Canis latrans), jackals, dholes (Cuon alpinus), and the African wild dog (Lycaon pictus).
An early offshoot from the Canis stock were the foxes (genus Vulpes). These smaller animals range in size from 4 to 24 lb (1.8–11 kg). There are 14 species of fox living in Eurasia, Africa, and North America, and they represent the typical canid. Many of the species have restricted ranges usually in arid areas. In almost any desert from the Namib to the Mojave, a small pale fox (V. pallida) can be found foraging at night for insects and small mammals. A few foxes, notably the large red fox (V. vulpes) and the gray fox (Urocyon cinereoargenteus) have been successful in more temperate areas and consequently have large ranges. Another unusual fox lives in the Arctic and its small ears and white coat are distinctive. However, genetic evidence suggests that it diverged quite recently from the swift fox (V. velox) that lives on the dry plains of Canada and the United States. The bat-eared fox (Otocyon megalotis) is specialized to eat insects with modified teeth and a special muscle to help it open its mouth rapidly and bite up its prey. Fossils with these special teeth show that the species diverged at least 3 million years ago (mya).
More specialized still is the raccoon dog (Nyctereutes procyonoides). With its stocky build and mask on the face, some experts have considered it a member of the raccoon family. The animal lives in dense, temperate forest often along watercourses in eastern Asia and Japan (and has been introduced to parts of eastern Europe as an escapee from fur farms). Genetic data show that it is clearly a dog but one that diverged early. Two continents require special consideration. The first is South America, which had almost no placental mammals until it became connected to North America 2–3 mya. It appears that either two or three kinds of canid moved south. One of these groups was successful, radiating into niches occupied by coyotes and foxes. The zorros of the Chilean and Argentinean deserts look very similar to their vulpine cousins in the rest of the world although they are independently evolved, and the culpeo (Pseudalopex culpaeus) of the pampas could pass for a coyote. There are two specialized South American canids that may represent independent lineages. The maned wolf stands taller than all but the largest gray wolves, but despite its size it is solitary and has a large
proportion of vegetable material in its diet. Its legs appear to allow it to see over the tall grass. The other peculiar South American species has the opposite morphology, looking like a barrel with short legs—the bush dog (Speothos venaticus) lives in thick forest where it hunts in packs, often along rivers and streams. It is an accomplished swimmer.
For the last 100 million years, there has not been a land bridge between Australia and Asia. It is therefore fairly certain that the dingos (Canis familiaris dingo) were brought with humans in their canoes and have gone feral. By now the dingos are a self-sustaining species with only their curly tails hinting at their ancestry. They even show a behavior, regurgitating water, that has not been reported from other canids. The dingos are one end of a spectrum from completely feral to completely domesticated. Other forms, such as the New Guinea singing dog, live mostly independent of humans while the village dogs of much of the Third World and the urban dogs of Western cities rely more on their owners.
Members of the dog family range in weight from 3–165 (1.3–75 kg). Coat colors and patterns vary significantly: black, black and white, brown, and red are all very common coat color in many dog breeds. As a family they have longer legs in relation to their weight than the other carnivore families. Their economical trotting gait allows them to cover large areas in search of prey, and most species can accelerate to 25–35 mph (40–56 kph) to run down prey. Top speed can usually be maintained for at least a mile, although prey are seldom pursued for that distance. Three species with shorter legs, the small-eared dog and bush dog of South America and the raccoon dog of eastern Asia live in dense forest. Five claws on the front feet and four on the back is typical. The fifth claw on the foreleg, the dew-claw, is almost vestigial and does not reach the ground. This claw is absent in African wild dogs.
Jaws and teeth are adapted to grab and chew prey. The tooth formula is 3/3, 1/1, 4/4, 2/3 for all species except the bush dog which has lost two molars on the upper and lower jaw, the dhole which has lost one molar on the lower jaw, and the bat-eared fox which has added two molars to the upper jaw and one to the lower jaw. The canines are longest in rodent catching species and shorter and sturdier in species killing larger prey. The last premolar in the lower jaw and the first molar in the upper jaw are modified into blades, or carnassials, which can cut flesh. The molars have grinding surfaces for crushing either bone or vegetable food. All the cheek teeth of the bat-eared fox look similar with multiple sharp cusps for penetrating insect exoskeletons, their primary prey.
The gut is simple and usually about five times the length of the animal. It is a bit shorter in highly carnivorous species. Most canids "wolf" their food, rapidly swallowing it. When pups are present they can regurgitate food up to 12 hours after eating.
It is not clear if this represents an adaptation to slow digestion or just a result of swallowing large bits in the first place.
Canids can certainly smell better than humans; their sight appears to be comparable to that of humans for most species but they have a higher ratio of rods to cones which should produce less color discrimination but an ability to operate at low light levels. Many species forage at night. Hearing is always acute, although the size of the external ears can be misleading as the ears are also used to radiate heat. The Arctic fox (Alopex lagopus) and the raccoon dog have small ears. Body lengths without tail range between 18.3 and 28.7 and (46.5–73 cm) and tail lengths are approximately 9.8–20.5 in (25–52 cm). Bat-eared foxes can hear the sound of termites foraging under ungulate dung and many species locate rodents by their rustle in the grass.
Wild canids occupy every continent except Antarctica and Australia. They occupy almost every habitat except permanent ice and they are rare in tropical rainforests. Domestic dogs have traveled with humans to every corner of the planet, from the South Pole to Death Valley, California.
The habitats used by the dog family are as diverse as their prey and it is easier to define areas that are excluded from use than to enumerate the ecosystems they occupy. Only two species live permanently in closed canopy forests, the bush dog in South America and the raccoon dog in east Asia. Both have short legs and a comparatively compact body to negotiate tangled pathways. The bush dog is found near water. Forests typically support a lower density of ground living rodents and lagomorphs than more open areas. "Edge" habitats with a mixture of woods and open country are favored by many canids. Several species notably the red fox and the coyote have benefited from the human conversion of forests into cropland. As noted above several canids, and especially the fox species, live in deserts. For kit foxes living in the arid areas of North America, it has been calculated that the moisture in their prey may be more important then the calories, i.e. they kill to drink. The large pack hunting species due to their mobility and catholic prey habits have the widest ranges of habitats used. The gray wolf's (C. lupus) enormous range includes tundra, ice flows, boreal forest, and the deserts of the Sinai and northern Mexico. However the African wild dog may be even more extreme. It has been reported from deep in the Sahara, from the montane forests of Ethiopia and from over 19,000 ft (5,790 m) above the snowline on Mt. Kilimanjaro.
Watching wolves jostle for dominance or red foxes in courtship is to witness a complex, fast, and subtle dance, incorporating not just movement but sounds, smells, and touch.
The outcomes of such interactions will determine who mates with whom and which animals will disperse, i.e., whose genes will be represented in future generations. In many cases the information acquired during play and other non-hostile interactions will eliminate the need for more openly hostile confrontations later. An individual can assess where he or she stands without having to fight.
The complex interactions are built up from simpler units or elements (e.g., a growl, or a wagging tail). These elements combine to form gestures and gestures between individuals form interactions. Interactions between pairs (or larger groups) form relationships. The pattern of relationships in a pack or group, in turn, determines the social system. Social behavior is a complex hierarchy that is hard to study. Luckily at the lowest level, the elements of social behavior are quite uniform among all the canid species (and recognizable by the owners of domestic dogs). As an example, among facial expressions all canids can snarl aggressively (upper lips lifted vertically) and "grin" submissively (lips retracted backwards). All species may show a defensive gape with the mouth held wide open as a shield. However, it occurs much more commonly in fox-sized species. The position and movement of the tail is similar in most canids and there is a graded signal from the tail tucked between the legs in defensive submission to tail held high in assertive dominance. In a study on jackals a scientist noted the exact element of behavior from twelve parts of the body (e.g., ears, muzzle, head turning, tail, hackles) as they were combined to produce gestures. The exact gesture virtually never repeated itself, reflecting the complexity of the interactions.
Vocalizations are integral in many close interactions and loud vocalizations, e.g., howls, can also carry to communicate with animals far away. One problem with studying vocalizations in canids is that we know they can hear at higher frequencies that we can. Humans probably hear only a part of the signal with their ears. (Ultrasound analysis allows us to "see" these noises but few have been analyzed.) As with the other elements of behavior, many of the squeaks, grunts and growls of close interactions seem similar across the canids (modified by the size of the voice box so that small species produce a higher pitched version of a noise). The growl is one of the sounds made by all canids and indicates threat. In an intense form it grades into a bark but barks are not commonly heard. However, this warning vocalization must have been found useful by the early domesticators of the wolf and is now triggered by almost any arousing or threatening stimulus in domestic dogs. The most evocative and loudest of canid vocalizations are designed for long distance propagation. Wolves, coyotes, and jackals all have howls (and interesting variants occur in African wild dogs and dholes). A pure-tone howl produced by a lone individual wavering around a single frequency acts to bring the pack together. The much more complex group howl which includes several individuals, some howling, some barking, and some growling is a territorial signal asserting rights to the land. It has been suggested that the complexity of the group howl with certain wolves changing pitch may deceive listeners into believing that the pack has extra members. It was believed for years that African wild dogs did not howl and packs are so spread out that a vocal threat like a group howl would have nobody to hear it. Recently group howls have been heard on the rare occasions when two packs do bump into one another. They have the same rich texture as group howls by wolves and seem to act as a threat. The dhole uses a pulsed whistle to locate pack members and a group howl between packs.
Olfactory communication is almost completely outside human perception but probably plays a major role in the life of a canid. Glands on the feet, skin, lips and anus are modified for secretion and in some species many of the glands associated with the hairs on the dorsal surface of the tail produce odor. Anal gland secretions rub off on feces and a variable mixture of bacteria in the anal sacs ensures that individuals have a unique odor. Sex and reproductive status, at least, are detectable in the urine. Urine marking by cocking a leg is seen in all adult species. Unlike domestic dogs where only males cock a leg, in wild canids the dominant male and dominant female both usually display the behavior. Marks are usually distributed around the edge of the territory and typically both members of the pair mark consecutively. The bush dog female has a peculiar marking behavior in which it backs up against a tree or post and deposits urine about two feet above the ground, presumably to increase its dissemination in the forest habitat. Bush dog males exhibit a typical leg cock.
Many of the most complex interactions occur in the context of dominance and submission. Whether in pairs or larger groups, stronger individuals have the power to monopolize important resources. The degree to which they assert their status depends on the extent to which they depend on other members of the group. In packs of African wild dogs, the species with the greatest social interdependency, dominance hierarchies are established in both males and female but their expression is muted. Expressions of subordination, or the willingness to accept the position or status of the dominants, are usually demonstrated effusively in all species. Subordination comes in two forms passive and active. In passive submission the inferior dog rolls on it back in front of the dominant. The gestures of active submission (or greeting) are derived from the begging of pups and subordinates mob a dominant thrusting their muzzles into his or her face. In wolves a dominant animal may either regurgitate or drop a bone or other food item in response to these greetings. Dominant individuals breed and the dominant or alpha male will prevent other males from mating while the alpha female will keep other females away. Relationships within monogamous pairs are usually fairly egalitarian with time spent resting and traveling, grooming and greeting together. Males are typically 10–15% larger than their mates which may explain why the majority of active submission seems to be directed by the female to the male.
Feeding ecology and diet
Most members of the dog family receive the majority of their calories from mammalian prey. At particular times and for particular species, fruit, insects, and other invertebrate prey are important. Every canid species observed to date has been seen trying to catch mouse and rat sized prey. While mice may be a supplementary food source for wolves, they are central in the diet of many fox species. Even a species as large as the Ethiopian wolf (C. simensis) at 38–44 lb (17–20 kg) subsists almost exclusively on small rodents. Species specialized for catching rodents have long, pointed jaws with elongated canines to maximize snapping speed and holding power. There is also a specialized behavior, the pounce, for catching rodents. The prey animal is located by sound, a rustle in the grass, and the fox launches itself upwards at an angle close to 45°, dropping down to pin the prey with its forepaws. On open ground rodents may be stalked with a final rush of 33–66 ft (10–20 m). Digging can also be effective,
particularly if a nest of newborn rats or mice is detected. Canids dig quickly and furiously using both front feet.
Rabbits and hares, the lagomorphs, feature in the diet of virtually every canid. Rabbits typically weigh from 1.1–4.4 lb (0.5–2 kg) while hares can weigh up to 10 lb (4.5 kg). In California, the 4.4 lb (2 kg) kit fox feeds primarily on the 4 lb (1.8 kg) black-tailed jackrabbit. Excluding the four or five species of specialized pack hunters, mammalian prey over 11 lb (5 kg) is usually taken only sporadically by members of the dog family. As a general rule, it is weak or young prey that are taken. Coyotes will kill young pronghorn and pairs of jackals cooperate to hunt young gazelles. Unfortunately, the young of domestic animals are sometimes vulnerable to this predation, although many studies show that lambs or calves being eaten by canids were probably stillbirths with embryonic membranes still covering the hooves.
A battle between a wolf pack and a moose weighing up to 1,650 lb (750 kg) and lasting up to several days in the snows of Nearctic winter is one of the grandest predator prey encounters left on the planet. The outcome is far from certain and the hoofs of the great deer can quickly kill an incautious wolf. Of course, it is usually the prey who are already weakened from starvation or disease that succumb. Comparable confrontations between African wild dogs and zebras (genus Equus) in Africa or Asiatic wild dogs or dholes with Sambhar deer (Cervus unicolor) in India, and perhaps the smaller bush dogs with capybara (Hydrochaeris hydrochaeris) in South America, reveal the rare cases in which members of the dog family form groups to hunt large ungulate prey. Popular opinion notwithstanding, there is little evidence that any of the pack hunters use complex hunting techniques such as setting ambushes or even relay running. By far the most common hunting behavior could be called "flush and rush." The pack moves through wooded or scrub habitat and will pursue any prey that breaks cover. These chases will seldom go for more than 1,640 ft (500 m). In open country the approach to prey can seldom be disguised and a pack's only chance is to stampede the prey and look for young or vulnerable animals that fall behind. Zebras in Africa and muskoxen (Ovibos moschatus) in the Artic that resist being stampeded and form a defensive circle will usually avoid predation. African wild dogs, wolves and dholes all have a top speed of about 35 mph (56.3 kph). The limit of the chase is set by the problem of overheating. After 3.5 mi (5.6 km), the effort of running in a wild dog has raised the body temperature to a dangerous 105.8°F (41°C) and only a special circuit of cool blood from the nose keeps the brain from over heating. Canids lack any specialized way to kill their prey (unlike the cats with their specialized throttle bite). Members of the pack will bite any exposed part, often grabbing a hind leg to topple the prey. Once on the ground the animal is usually quickly ripped open and dies quickly. All three of the main pack hunters have been seen to leap up and catch the upper lip of large prey. Once the lip is bitten the struggles of the prey are greatly reduced. (Humans
have also discovered this and will twist a rope around the upper lip of a horse to quiet it.) Hunting is only rarely more efficient when the size of a pack goes above four individuals, but pack sizes in all the pack hunters often reach 20–30 animals. It is the very large prey items that can provide food for all the extra pack members.
Almost all members of the dog family will eat fruits and coyotes have been known to cause damage to commercial melon farms, while Aesop tells a story of the fox and the grapes. Young, dispersing canids often resort to fruit before their hunting skills in new territory are perfected. The maned wolf of South America feeds on fruit from the genus Solanum. Invertebrates are always a component of the diet of foxes. In the foxes of arid lands, where vertebrate prey may be scarce, most species will eat beetles, scorpions and spiders. The red fox of more temperate latitudes often includes substantial quantities of earthworms in its diet. In South America, the crab-eating fox (Cerdocyon thous) depends on its crustacean prey at certain times. Among non-mammalian vertebrates, any canid will pick up and eat the eggs and nestlings of ground nesting birds, and foxes may indeed kill many chickens if they get into the henhouse.
Another topic for this section is the killing of one canid species by another, "dog eat dog." In North America in particular, competition between members of the dog family may result in one species killing or driving off another. If wolves are common, coyotes are usually sparse and wolves have been seen to chase coyotes vigorously and kill them. In turn, coyotes are an important cause of mortality for the kit foxes in California, though the fox carcasses are not always eaten. To make matters worse, the small and endangered kit foxes are also persecuted by the larger, introduced red foxes.
Golden jackals (C. aureus) are common on the scrubby sand dunes just south of Tel Aviv in Israel. In December a young adult female approaches an adult male who, by his marking behavior, has established a territory for himself. The female is playful and submissive. The male is not very responsive at first and snaps at the female but she follows him and over the next two months they are seen resting and grooming together until they are seldom seen apart. Sometimes the female stands directly in front of the male to form a "T" and the male may put his forepaws on her back. In March the female is fully sexually receptive for about a week and some of the male's mountings end in a copulatory tie in which the head of his penis swells so it cannot be extracted for 4–5 minutes. Nine weeks later a litter of five pups is born in an underground den. For the first few days after giving birth, the female stays with and nurses the young while the male provides her with food. Soon after their eyes open at two weeks the pups start to crawl around and usually emerge above ground at about three weeks. The parents usually take turns staying by the den and foraging. Most food is carried back in the parents' belly and regurgitated, but larger items may be carried back whole. By three months the pups have achieved nearly adult size and over the next three months they become independent of their parents (although willing to beg if the opportunity presents itself).
The reproductive biology of the jackals in Israel is typical for the majority of the canids. The two salient features are monogamy and regurgitation, a combination that is common in birds but not seen in any other group of mammals. The two are linked. By having an efficient way to provision his young, a male canid can usually be more successful reproductively by helping his offspring than by attempting to mate with many females. Monogamous bonds, in all species studied to date, extend over several breeding seasons and are sometimes life-long. (In the pack-living species, most mating occurs between the alpha animals in the male and female hierarchies. Although a pair bond develops, it is determined by the outcome of competition within the sexes.)
Canids are almost always territorial. It pays a pair to keep other members of their species out of a defined area. This protects food supplies, keeps conspecifics away from the den where cannibalism could occur and perhaps most importantly keeps members of the opposite sex away from mates. It is striking that in territorial encounters aggression is usually between members of the same sex. Territoriality is not seen in African wild dogs that roam over such large ranges that they cannot defend its boundaries. However, one pack will chase another away if they meet. At the other end of the spectrum, the home ranges of bat-eared foxes overlap considerably. They live almost exclusively on insects. Food taken by other foxes does not reduce a resident's supplies and defense is not economic in this situation.
A territory that can supply the needs of a breeding pair can often provide food for other animals to survive. In many circumstances it is very beneficial for a young animal to remain on the territory where it was born. Most of the mortality in canids happens when young animals first move away from their natal range. Their hunting skills are not perfect, and they have to move though land occupied by hostile conspecifics (and not infrequently human persecutors). The retention of young in the parental territory is now known to be very common in the dog family. These animals may stay through one or more breeding seasons. These extended families usually gather for a morning and evening greeting although each individual will find food alone. Young from previous years are often present at the birth of the next litter, and regurgitate food and act as babysitters. In most cases this appears to help the parents reproductive efforts, but in one case the "helpers" in a pack of African wild dogs under food stress were seen to pull food from the mouth of the young pups. It is probable that pack hunting developed when pre-existing groups cooperated to tackle larger prey. Even the wolf, when it is living in forested or more arid regions, breeds in pairs and lives in the summer on comparatively small prey. Packs and group hunting occur in the winter.
The rule of monogamy has a few exceptions. In African wild dogs, the alpha female has been seen to mate with more than one male during her estrus, and the hierarchy among the males is unstable so that in different years the same reproductive female will mate with different males. The species is effectively polyandrous, a system in which one female has
many male partners (despite the fact that at any one moment there is close relationship between the alpha pair). African wild dog females also produce very large litters averaging 10 pups. There is intense competition in this species between females to monopolize the help (in the form mainly of males) needed to raise their pups. At the other end of the spectrum there are cases in several fox species and most notably in the bat-eared fox of two females sharing a den with a single male. This is a form of polygyny in which a male has several female partners and it is also observed in red foxes. In contrast to the African wild dogs in which the regurgitation and hunting skills of the pack are crucial for survival of the pups, in the largely insectivorous bat-eared fox, the male can contribute little to his mate. An insect diet does not provide the nutritious surplus that can be regurgitated. In this species the male's main investment is to babysit while the females forage and produce milk. It is the same effort to babysit one versus two litters, and the females should choose to breed in the areas of most reliable insect abundance. Females usually produce one litter a year and in temperate regions birth usually comes in early spring. Pups require the most food several weeks after they are born, and an early spring birth peak means that growing young can be provisioned from the prey born in early summer. Litter size runs from two to 20 with an average of 5–6. Litter size is larger than that of the other carnivore families. The maned wolf, a large, solitary species with a largely vegetarian diet, gives birth usually to just two young while African wild dogs and Arctic foxes may give birth to 15–20 young. In the Arctic foxes the large litters occur in years of maximum lemming abundance.
As humans co-opt the resources of the planet, the capacity of any carnivore to survive depends on its ability either to coexist with humans or to live where humans cannot or have not introduced settled agriculture. Every species of canid has interactions with humans and often their domestic dogs. Several adaptable species, notably the red fox, the gray fox, the coyote, and the Asiatic golden jackals, have found the modification of the environment by humans to their liking and are flourishing. Most other species are less fortunate.
Only one species of canid has gone extinct in recent times. The last Falkland Island wolf (Dusicyon australis) was seen in 1875. These large, coyote-like animals were common on the Malvinas, which lie 250 mi (400 km) off the coast of Argentina. It is not clear whether they were domestic dogs that went wild or an indigenous species that crossed from the mainland when sea levels were very low. Their tameness and habit of greeting humans when they arrived suggests the former. However, their friendly traits made them very easy to kill when Scottish sheep farmers arrived in the mid-nineteenth century. Although only one full species of canid has disappeared, several races or distinguishable subspecies have been lost. Several types of wolves that occupied the American west and Europe have vanished, as have races of the African wild dog that used to live in south and west Africa. In general the large pack hunters have been excluded from areas of settled agriculture and now survive only in wilderness. The wolf in Europe has
been able to survive in quite small areas of uncultivated land and in frequent contact with humans. The problems of the African wild dog, the wolf of that continent, are more severe. The world population may be as low as 5,000. Perversely it does not necessarily flourish in the rich game reserves as it is competitively inferior to lions and spotted hyenas, and loses its kills to the larger predators. Its ability to travel very large distances and live on low densities of prey may allow it to survive in the large tracts of semi-arid land in the north and east of the continent. The fate of the dhole, the pack hunter of east Asia, is largely unknown but it has certainly suffered a huge contraction of its range.
Among the intermediate and smaller species, the forms that are most endangered have restricted ranges. The Ethiopian wolf, with about 500 survivors, is the most vulnerable species. This animal lives only on rodents above 9,840 ft (3,000 m) on Ethiopian mountains. Its range has been shrinking since the earth started to warm up at the end of the last Ice Age and it is now reduced to seven small populations largely isolated from one another on the tops of different massifs. Islands restrict the range and hence population size of two other endangered species. The island fox (Urocyon littoralis, related to the gray fox) exists only on an archipelago off the coast of southern California, and Darwin's fox (Pseudalopex fulvipes) lives almost exclusively on Chiloe Island off the coast of Peru.
The red wolf of the southeast United States is a small canid and the last known free-living sightings were made in restricted habitat of coastal marsh, although there are historic records from a range of wooded environments. Most of the surviving animals were brought into captivity, and genetic analysis has shown that all contain a mixture of gray wolf and coyote genes. This hybrid form represents a unique canid and has been treated as a self-standing endangered species. Even after some successful reintroductions, its numbers remain critically low. Programs for reintroducing and translocating gray wolves are currently ongoing in North America. In a recent review of canid conservation, 9 species or a quarter of the family had too little known about them to draw any conclusions about their rarity. Several of these species, such as the fennec (V. zerda) from the Sahara are living in areas where human impact is still minor.
Significance to humans
Some Native Americans near the Arctic Circle share their land with wolves. Both subsist mainly on the caribou herds. Although guns have upset the balance of the relationship in the twentieth century to the present, humans still talk primarily of their respect and admiration for their fellow carnivores. The two hunters do not interact frequently, although each will scavenge from the other or commandeer kills from smaller groups. A wolf-trimmed coat is a mark of a skilled hunter. For the past million years most humans, like the Native Americans, have probably lived within earshot of the howls of members of the dog family, but there is no archaeological evidence that they had strong ecological or economic interactions. However our hunter-gatherer ancestors certainly knew about the animals around them and the distinguishing characteristics of our canid neighbors are deep within the folklore of most cultures. From Romulus and Remus to Mowgli, the nurturing characteristics of the wolf family are renowned while the tricks of the coyote and the fox are legendary.
The spread of agriculture marked a downturn in canid-human relations. Domestic stock from chickens to cows are tempting targets and even cultivated fruit, like melons and grapes, are simple for a fox or a coyote to harvest. The wolf has suffered the most for its potential to kill domestic stock. From 1860 to 1920 a war waged on the species in western North America using guns, traps, and poison was over-whelmingly successful. By the 1930s only a few stragglers survived close to the Mexican border or in the forests of Minnesota where immigrants from Canada were available. Intensive settled agriculture had long since driven wolves into the corners of wilderness left in Europe. The wolf had become a creature of the wild and the forest and a bogeyman for the village dwellers. Fear replaced respect and Little Red Riding Hood's grandmother replaced the mother of Rome. However, at least in the Western world, attitudes to wolves are rapidly undergoing another 180o turn. They are now the icon of the wild places and wild nature that we are losing.
The wolf, a large animal often in packs, has been much easier to persecute than the intermediate sized canids—the dingo, coyote, jackals, and red fox. These species do not require a prey base of large mammals and can live surreptitiously at high population densities. Efforts to control these species have seldom been successful despite their depredations on the young of domestic stock especially sheep and goats. These intermediate sized canids live where they can find food. Dog food and earthworms provide nourishment for red foxes in the middle of English cities, while domestic cats are a staple in the diet of the coyotes living in Los Angeles, California.
Approximately 15,000 years ago a symbiosis developed between wolves and humans. Wolves, as village dogs in many parts of the world today, probably acquired some of the scraps from the increasingly efficient hunting of the humans. The
humans, in turn, chose wolves that were efficient in sounding an alarm (barking), and sometimes protecting stock. Initially in this relationship the benefits the wolves derived from food may have outweighed the advantages to their humans and it seems likely that wolves domesticated us. However, once wolves began reproducing under human control, selective breeding allowed humans to take canid characters that were useful to them and produce guard dogs, swimming dogs, retrieving dogs, and ironically foxhounds and wolfhounds; dogs to hunt other members of the family. In the western world traits of active submission and obedience have been selected to produce our loyal and friendly companion animals.
List of SpeciesGray wolf
African wild dog
Canis lupus Linnaeus, 1758, Sweden. Twenty-six races are recognized. The largest races live exclusively on large ungulates while the smallest are from the desert regions. Two genetically distinct stocks appear to occur in North America, with wolves in the western part of the continent perhaps representing a separate colonization from Eurasia.
other common names
English: Timber wolf; French: Loup; German: Wolf; Spanish: Lobo.
The gray wolf is the largest of the canids with males weighing up to 132.3 lb (60 kg) while females are typically 10–15% smaller than males. Shoulder height is from 26.0–31.9 in (66–81 cm). In the small desert wolves, e.g. the Mexican wolf, males weigh 66 lb (30 kg) or less. Coat color is typically an agouti brown but can vary from pure white (in the Arctic) to black, and shades of rusty color. The belly and chest is white; the fur is long with a bushy tail. The skull and teeth are large, but are less specialized for eating flesh than those of the dhole and the African wild dog.
Wolves occur where suitable densities of prey, usually ungulates, can provide food. This includes Arctic ice flows and the Sinai desert and all habitats in between.
The species used to inhabit the whole of North America, south to central Mexico. It also lived throughout Eurasia including the Sinai peninsula, but excluding the southern third of India and the southern portions of Southeast Asia. It has been exterminated from most of the U.S. except for a population in northern Minnesota, and a newly expanding population in the northern Rockies. A few Mexican wolves have been reintroduced to New Mexico in the United States. Wolves were wiped out in most of western Europe by 1750. Three small populations remain in the Iberian peninsula, the Apennines in Italy and south central Norway. Wolves have also been eliminated from the eastern two-thirds of China.
Most wolves live in small social groups of two to six individuals, sometimes with pups. Packs are thought to consist of related individuals and females typically join males that have an established territory. However, many wolves such as those living in less productive areas are only seen solitarily or in pairs and packs themselves are fluid. Groups may split in the summer while individual pairs breed and then come back together
into larger groups in the winter. The size of the pack seems to be related to the size of the prey killed. A large group can obtain a meal from a large carcass. Little is known about the social behavior of wild wolves. However, information from many captive packs reveals a rather dictatorial society in which the alpha male exerts his authority by clasping the muzzle of the subordinates in his mouth. The other wolves show elaborate active submission rubbing their mouths against his head and licking his muzzle in a gesture derived from infantile begging. Alpha males have been seen to pick up a bone, with no food left on it, and drop it among the subordinates as a gesture of their dependence on his food provisioning.
feeding ecology and diet
Ungulates from 44.1–220.5 lb (20–100 kg) form the core of the wolf's diet. However prey up to the size of a moose (1543 lb; 700 kg) and as small as a mouse are included. Members of the deer family are the most common prey from the caribou of northern latitudes to the mule deer of the SW United States. Beavers are commonly killed in North America. Italian wolves raid human trash and some predation on livestock has been reported. There are no authenticated reports of wolves killing humans in North America, and no recent reports from Europe. Poor people in Europe and northern Asia may have been attacked by wolves in the past and there are a few reports of infants being taken by wolves in India.
Monogamous. Packs or pairs breed annually with young born from March-July depending on latitude. Gestation is 61–63 days and young are born blind in an underground den. The mother nurses her young and licks them to stimulate defecation and urination which she consumes so as to keep the den clean. Eyes open at about 14 days and young crawl to the surface a few days later. All members of the pack feed the pups with regurgitated food, and may carry some food items back to the den. The pups spend an increasing amount of time out of the den usually playing. As the pups become more mobile, adults may become less tolerant of their sharp teeth and frequently lunge at the pups to keep them at bay, but without inflicting any serious bites. By three months, the pups are starting to follow the pack, and will leave the area of the natal den. However, they usually cannot keep up with the hunts and are left alone or with a babysitter. The young are not fully mature until about two years old.
As indicated above, the wolf has been exterminated from a considerable portion of its range. It is a very rare animal in the United States (outside Alaska) and is listed as endangered in the U.S. Endangered Species Act. Recovery efforts have included protection and habitat acquisition in Minnesota, captive breeding and reintroduction of the Mexican wolf and reintroduction in the Yellowstone ecosystem. Wolves, without help from humans, have recolonized parts of the northern Rockies in Idaho and Montana. The remnant populations in Europe are being managed. The wolf does not survive in areas of settled agriculture but in the wilder parts of its immense range, it appears to exist in low numbers despite human persecution and some trapping for its fur. The gray wolf is not listed as a threatened species globally by the IUCN.
significance to humans
Wolves have been a potent force in human culture both economically and culturally. Wolves are still hunted through much of eastern Asia where people still herd their sheep and goats for a living. In Alaska they were killed using helicopters because they were blamed for depressing the caribou herds hunted by sportsmen. For people living a long way from wolves, the species and its howl represents the essence of wildness and it is a mark of machismo to own the dangerous and semi-wild wolves and wolf hybrids.
Canis simensis Rüppell, 1835, Ethiopia. There are some slight differences between wolves found on either side of the Great Rift Valley, suggesting isolation for part of the Pleistocene.
other common names
French: Loup Abyssinie; German: Aethiopenfuchs; Ethiopian: Ky Kebero.
The Ethiopian wolf is a long-legged, long-snouted canid with males weighing 35 lb (16 kg) and females 28.7 lb (13 kg). It is 23.6 in (60 cm) at the shoulder. The coat is a bright red with black on the back of the ears and tail. The base of the tail and lower legs are white, with white patches on the throat and chest.
The species is restricted to seven small areas, five north of the Rift Valley and two south of the Rift Valley, all in Ethiopia.
An extreme specialist, the Ethiopian wolf lives in treeless areas above 9,843 ft (3,000 m), in Afro-alpine habitat.
The species is territorial and monogamous. Young often remain on their natal territory producing small packs of 2–8 members. Females leave their home area sooner than males so packs have more males than females.
feeding ecology and diet
Rodents constitute 95% of the diet. The prey include the giant mole rat 10.6–31.7 oz (300–900 g) as well as smaller rats and mice. Hares are caught occasionally. Prey is sighted or heard in the open country. The wolf will stalk until able to make a final dash of 16.4–65.6 ft (5–20 m). Prey may also be dug out of their tunnel systems. Scavenging occurs. Predation on livestock is exceedingly uncommon.
Monogamous. Breeding occurs seasonally with mating in August and September with young born two months later. Litter size is from two to six and all members of the pack bring food to the pups. Only the alpha pair breed. Juveniles will follow the pack at six months but full adult stature is not achieved until two years.
Of the seven populations, only one, in the Bale Mountains, numbers more than 100. The total available habitat is very limited, and humans encroachment is continuing. World population is less than 600. There are none in captivity. Listed as Endangered by the IUCN.
significance to humans
The Oromo people who live among Ethiopian wolves show little or no antagonism towards them, recognizing that they are not a threat to their herds. They are sometimes shot in other parts of their range and their livers are thought to have medicinal properties.
African wild dog
Hyaena picta (Temminck, 1820), Mozambique. There is some genetic differentiation between dogs from East and South Africa, but there is also overlap between the types.
other common names
English: Cape hunting dog, painted wolf; French: Lycaon; German: Hyanenhund.
The largest canid in Africa, it weighs 39.7–79.4 lb (18–36 kg). It is 27.6 in (70 cm) at the shoulder. The wild dog has a distinctive spotted coat. Its short hair is divided into irregular yellow, black and white markings with each dog unique. The dark muzzle, large rounded ears and white tail tip are invariable.
Formerly distributed throughout all of sub-Saharan Africa outside the equatorial forest zone, the species has been extirpated from most of western Africa and southern Africa. The species still survives over much of eastern Africa and parts of the Sahel but the viability of populations outside its strongholds in Tanzania and Botswana is unknown.
The species is most common in savanna and lightly wooded country, but it has the ability to live in a wide range of habitats from desert to mountain forest.
The wild dog is the wolf of Africa but with a more extreme adaptation to pack living. Packs range from two to 30 with an average of six adults and a variable number of pups. Members of a pack spend 95% of their lives in sight or earshot of one another. Resting, which takes 60–85% of their lives, is often
done in close contact. Packs are composed of related individuals. Males are more likely then females to stay in the pack where they were born and usually outnumber females in the population.
feeding ecology and diet
Predominant prey is small to medium sized antelopes from 22.0–132.3 lb (10–60 kg). Thomson gazelles, Gazella thomsonii (44 lb; 20 kg), and young wildebeests (Connochaetes spp.) are the chief prey in the open areas of eastern Africa. Impala, Aepyceros melampus (110 lb; 50 kg), are the staple food over most of the wooded areas of eastern and southern Africa. The species will take from the size of a hare (4.4 lb; 2 kg) to a zebra (441 lb; 200 kg). Packs hunt mainly in the mornings and evenings. In wooded areas, packs fan out and flush prey. In open areas dogs may slow and lay their ears back as they approach prey. The dogs run after fleeing prey at up to 35 mph (56 kph) for 3.5 mi (5.6 km). However, most chases are much shorter. Sick and gravid prey are vulnerable. The lead dog in the chase attempts to grab the hind leg of the prey. Once the animal is on the ground, it is quickly eaten.
Polyganorous, though there is a pair bond between the alpha male and alpha female in each pack. They rest together and are the only dogs to mark using a cocked leg. The alpha female produces pups annually with some seasonality especially in southern Africa. Subordinate adult females sometimes breed, but are seldom successful unless the pups of the dominant female die. Females produce an average of ten pups in an underground den after a gestation of 70–72 days. All members of the pack raise the pups; they regurgitate food while the young are still close to the den and later relinquish kills to the pups when the latter are able to follow the pack. Pups are not efficient hunters until 14–18 months. Survival through the first year is very low but larger packs tend to be more successful.
African wild dogs still have a wide distribution, but their population density is often very low. The total world population probably does not exceed 7,000. They do not survive well in competition with lions and hyenas and are susceptible to several diseases probably transmitted by domestic dogs. However, they are able to survive on very low prey densities in arid habitats. They are listed as Endangered by IUCN but much is unknown about their population status.
significance to humans
Wild dogs appear very rarely in rock paintings or folk tales suggesting that the species has never been common or an important part of the cultural landscape. In this century they have suffered the same fate as the wolf and been exterminated as a killer both of livestock and innocent prey populations. This attitude is changing although a wild dog extermination officer was employed by Namibia into the 1970s and pastoral people in many areas will kill the species on sight. In the Western world, its status as the wolf of Africa is providing kudos and protection.
Canis vulpes Linnaeus, 1758, Sweden. Forty-six races or subspecies have been recognized over the species' immense range.
However, much variation appears due to climate, with smaller, paler animals in the south, e.g. Egypt and larger, darker foxes in places like Alaska.
other common names
English: Silver fox (a color morph used in the fur trade), cross fox (a dark, naturally occurring color morph); French: Renard; German: Fuchs; Spanish: Zorro.
The largest of the true foxes, the genus Vulpes, red foxes can weigh up to 24.3 lb (11 kg) but males in Europe average 14.8 lb (6.7 kg) while females weigh 11.9 lb (5.4 kg). The shoulder height is 13.8–15.7 (35–40 cm). The body color is almost always some shade of red but it can vary from bright to grayish. The belly is paler and the muzzle, legs and backs of the ears are black. The snout is long and the canines long and pointed, but the molars are not very large.
The red fox occurs across Europe and Asia as far south as the Himalayas. It is found in Egypt and Algeria in Africa, and in northern North America extending along the Rockies and to the Gulf Coast in the United States. It has been introduced into Australia and occupies all but the northern parts. It was also introduced in the eastern section of North America.
Red foxes are uncommon in densely wooded habitats, but otherwise show great flexibility in their habitats. They can live in semi-desert scrub in Africa and on the tundra in Alaska. They have adapted well to humans, foraging in towns and hunting in the areas cleared for agriculture.
Red foxes are mainly monogamous and territorial. Often cubs will remain on the parental territory. These non-dispersers are usually female and may help with raising the next litter. Like most canids, red foxes remain playful for most of their lives and there are boisterous games of chasing and mock fighting among the pups, with the adults sometimes joining in.
feeding ecology and diet
Mammals, mainly rodents and rabbits, are the mainstay of the diet in most places. However, a wide range of vertebrate and invertebrate food is eaten including earthworms, beetles, the young of ground nesting birds, and human scraps. Lambs are found around red fox dens, but in many cases the victims are known to be sickly or stillborn. Red foxes use their ears to locate the rustle of a mouse in the grass and then launch themselves in a pounce to land on their prey. Other food items appear to picked up opportunistically as they traverse their territories at night.
Monogamous. Cubs are born after a 50 day gestation in an underground den, usually at the end of winter. Litter size is from three to 12 with seven typical in western Europe. The mother nurses the litter for four weeks. The cubs start to eat solid food regurgitated by the group starting at about three weeks. At 10–12 weeks, the young will start to forage on their own but their hunting skills will take nine to 12 months to develop. Most young disperse from six to 12 months.
Although persecuted for predation on game birds and livestock and hunted for fur, red foxes have continued to flourish and have colonized the urban habitat, often without the knowledge of the human inhabitants.
significance to humans
The fox is the sly trickster in the folklore of the Old World. The term "sour grapes" comes from Aesop's anthropomorphic fox. Predation of chickens has probably been going on for several thousand years, but the nineteenth century brought more conflict as game birds and lambs born in the fields provided food. Foxes have been persecuted by guns, hounds, and poison, but have seldom been exterminated. The sport of fox-hunting in England has ensured the survival of the quarry, and now that the sport is close to banned, the fox's range may contract. A vigorous campaign to control foxes in western Europe so as to limit the spread of rabies, has not eliminated the species.
Vulpes cana Blanford, 1877, Pakistan. No subspecies recognized. Blanford's fox is a small but otherwise probably typical member of the desert foxes, a group of nine species all in the genus Vulpes, which live in the deserts of the Old World and North America. Genetic evidence shows that the fennec fox is Blanford fox's closest relative.
other common names
English: Afghan fox.
The second smallest of the canids after the fennec, Blanford's fox weighs 2.2–3.3 lb (1–1.5 kg) and stands 10.6–11.8 in (27–30
cm) at the shoulder. Its bushy tail is 70% the length of the head and body, second only to Rueppell's fox in this category among the canids. The coat is a uniform sandy-gray with paler undersides and a dark band along the back. The tail tip is black. Shoulder height is 11.0–11.8 in (28–30 cm). The teeth are small but otherwise typical for the family with a shearing carnassial and grinding back molars.
The central part of the species range is in the central Asian steppes including Pakistan, northern Iran, Afghanistan, and parts of Turmenia. Since 1970 three outlying populations have been discovered in the Negev desert of southern Israel, in southwest Saudi Arabia and in Oman. With its small size and nocturnal habits, it is possible that other populations will be found in the deserts of the Middle East.
In the area where the species has been studied in Israel, it has a very precise habitat. It lives on rocky hillsides. It does not venture above 6,560 ft (2,000 m) and usually avoids the flat, flood plains of lower elevations.
In Israel, pairs live in small territories averaging 0.6 mi2 (1.6 km2). A female from the previous litter often shares her parents' range. The species is strictly nocturnal, traveling about 5.6 mi (9 km) per night during eight hours of foraging.
feeding ecology and diet
The species eats mainly insects and fruits. In the Negev of Israel, beetles, ants, termites and grasshoppers were all snapped up together with dates and the fruits of other palms. In central Asia, olives are a staple food. Rats and mice are taken when encountered but constitute less than 10% of the diet. The species can survive without drinking water. Its fluid comes from its food and it has been calculated that the water provided by food may often be more important than the calories. Foraging is almost always solitary and consists of slow and systematic investigation stones and bushes in search on insects. The foxes dash after small vertebrates when flushed.
Monogamous. The species does not try to dig dens in its rocky habitat and the young are born in piles of boulders. The young survive on their mother's milk alone for the first two months of life. Although the male may be present at the den, there is no evidence that he regurgitates or regularly carries food to the young. An insectivorous diet does not make regurgitation practical. At eight weeks, the young start to forage with their parents and at three months they forage on their own.
Blanford's fox is seldom seen and has been considered one of the rare carnivores of central Asia. However is not clear if it is rare or just secretive. It appears to exist over a large range of at least 772 mi2 (2,000 km2), and is known to live close to humans. It is hunted in several areas. It is listed by IUCN as Data Deficient.
significance to humans
Blanford's fox is hunted for its fur in parts of Asia, but is often inconspicuous to humans.
Canis megalotis (Desmarest, 1822), South Africa. Two subspecies, O. m. megalotis from southwest Africa and O. m. virgatus from northeast Africa.
other common names
French: L'otocyon; German: Loffelhund.
The bat-eared fox is a typically sized fox weighing from 4.9–9.9 lb (2.2–4.5 kg) and standing 11.8–15.7 in (30–40 cm) at the shoulder. The body is ash gray, paler below, with black at the extremities. The tail is bushy and the ears large. Its teeth are unique in the canids with a series of 32 cheek teeth, all with high cusps for puncturing insect exoskeletons.
The species exists in two separate areas, the southwest and northeast of Africa. These two areas of the continent have remained dry even during the wettest periods of the Pleistocene.
Bat-eared foxes prefer open short-grass habitat. They need soil in which they can dig holes for refuge and for breeding. They occur at lower densities in savannah woodlands and desert areas.
Pairs or groups often rest in the vicinity of one another, and get together to play and groom each other at dusk. Almost all foraging occurs at night, and is done solitarily. Bat-eared foxes are preyed upon by eagles and mammals such as jackals and cheetahs. When above ground in the day, they keep a look out for raptors. Against mammalian predators they use a zig-zag run in which their large tail acts as a rudder. They seek refuge underground.
feeding ecology and diet
Termites and beetles (adults and larvae) are the principal food. Insect food is often detected by sound. The grazing termite, Hodotermes, makes a noise as it chews grass stems, and bateared foxes can hear the sound of termites foraging on the underside of ungulate dung and the noise of beetle larvae in a dung beetle ball. Mice and other small vertebrate prey will be snapped up if encountered and may be common in the diet when young pups are present.
The species is typically monogamous but dens with two breeding females are not uncommon. In some of these cases, it is known that a female pup from the previous year bred at her parents' den. Gestation is long for a fox, 60–75 days, and lactation is very long, from 14 to 15 weeks. Both of these modifications are related to an insect diet that provides a low but constant level of nutrition. Males do not regurgitate insects and hence play a small part in feeding pups. They do play a major role in guarding the pups, thus allowing the female a chance to forage so that she can produce milk. In another difference from other canids, bat-eared foxes are often non-territorial, with dens clustered in areas of suitable soil. Groups mingle on the foraging grounds. It seems that it is not worth expending energy keeping conspecifics from insect resources.
The bat-eared fox remains an inconspicuous but widespread inhabitant of dry areas in southwest and northeast Africa. It is not persecuted and has benefited from cattle ranching in southern Africa which creates short grass habitat, and grazing termites. Disease epidemics sometimes decimate local populations.
significance to humans
Together with all canids, bat-eared foxes can carry rabies but otherwise have no significant interactions with humans.
Canis procyonoides (Gray, 1834), Canton, China. The raccoon dogs from the islands of Japan are consistently smaller than those of the mainland and have a different chromosome count as well as other genetic differences. Genetic analysis shows that the raccoon dog is an early independent offshoot from the main canid line.
other common names
French: Chien viverrin; German: Marderhund.
The raccoon dog is a medium-sized canid. Its weight fluctuates markedly through the year. An average summer weight is 11.0 lb (5 kg) increasing to 16.5 lb (7.5 kg) before winter hibernation. It stands 7.9–9.8 in (20–25 cm) at the shoulder. The distinctive mask with a black muzzle and a broad white stripe across the forehead gives the species its common name. The very long coat makes the animal look stocky and barrel-like. Although its legs are not long in proportion to its body, they are not as short as those of several South American canids. The teeth are relatively small.
The original range of the species is the temperate lands of eastern Asia including China, Siberia, and Manchuria. It also inhabits the Japanese island chain. It was introduced to the USSR for fur farming in the 1920s and has spread widely. It is now found from Finland to Germany and east to the Himalayas.
The species lives in a variety of wooded and forested habitats. It prefers mixed woodlands and often uses water courses. It can tolerate some human encroachment.
At high latitudes, the raccoon dog goes into a deep torpor during the winter, the only canid to hibernate. Groups of the animals sometimes occupy the same den for the winter. Individuals gain up to 50% of their body weight in the late summer and autumn. Males are usually the first to reach their hibernation weight with breeding females and young taking an extra month. Pairs occupy a common range although the degree of territoriality is not clear. Groups of raccoon dogs regularly gather at food sources, and breeding dens are sometimes clumped. The main source of mortality recorded for the species is predation by wolves and, less commonly, red foxes.
feeding ecology and diet
The species has a varied diet, although insects and mice are often the most common items. Like the raccoon (Procyon spp.), they regularly eat fish and other aquatic foods like frogs, snails, and crabs. In the summer they may eat berries and fruits.
Monogamous. Breeding occurs in the early spring. After a gestation period of 59–64 days, three to eight pups are born in an underground burrow, often an old badger den. The male plays a very active role in raising the pups both provisioning his mate and young and staying at the den to protect the family. The pups reach maturity at about a year.
Not threatened. The species appears to be continuing to expand its range in Europe. It has colonized much of the forested lands of Russia. In its native range it is still common in much of Japan. Information from other areas is sketchy, but it is known to be uncommon from areas of northern China that are now under industrial agriculture.
significance to humans
No fewer than 200,000 raccoon dogs are hunted annually for their fur and a large number are harvested on fur farms. It has been considered an omnivorous pest, like its namesake, the raccoon, as it has spread across Asia. However, even in densely populated Japan, it has remained largely inconspicuous.
Canis brachyurus (Illiger, 1815), Paraguay. No subspecies are recognized. The maned wolf is genetically distinct from most of the other South American canids.
other common names
German: Mahned wolf; Spanish: Lobo de crin, lobo guara.
Maned wolves, at 29.1–34.2 in (74–87 cm) at the shoulder, stand taller than all but the largest gray wolves, but at 44.1–50.7 lb (20–23 kg), they weigh less than half that of most wolves. They have the longest legs in proportion to their spine of any canid. Their skulls and teeth are not dissimilar from those of coyotes with long, fine canines. Their coat color is a distinctive golden red with dark hairs on the back of the neck creating a small mane. The lower legs are black and the throat and often much of tail is white.
The species occurs in the southern two-thirds of Brazil, extending south and west into Uruguay, Paraguay, eastern Bolivia, and northern Argentina.
The species can live in a variety of habitats outside the rainforest. However, it appears that its long legs evolved for life in the grasslands and pampas. It can survive in areas of mixed farming and will forage in lightly wooded areas.
The maned wolf is probably the most solitary of the canids. Males and females appear to share a defended territory of up to 12 mi2 (30 km2), but interactions between the pair are said to be very uncommon. Their bold white markings on the tail and throat allow visual signals to be communicated at a distance as does the harsh bark and typical patterns of marking by urine and feces. Maned wolves may leave feces high up on rocks and termite mounds.
feeding ecology and diet
The only comprehensive study of diet showed that most abundant food was the fruit of a bush related to the tomato. Overall plant and animal material were equally common with rats and mice, birds and lizards also taken. The species has a reputation for eating chickens. Almost all foraging is done from dusk to dawn.
Monogamous. Breeding is very seasonal with a small litter size of 2–6 young. The pups are born in a protected site above ground, in a rock crevice or thick bush. The species long legs may make it hard to dig. The role of the male in helping to raise the young in the wild is still not clear. Usually only a single animal is seen with the young. In captivity however, male maned wolves will provision young. It takes about a year for the young to develop to their full height.
Although the range of the species is large, it seems that they live at very low population densities. With an estimate of only one wolf per 116 mi2 (300 km2), the world population may be under 3,000. The species is persecuted for raiding hen houses, and does not live in areas of intensive settled agriculture. On the positive side, it has been able to colonize areas where forests have been recently cleared. Although officially protected and recognized as endangered in its native lands, it is listed only as Lower Risk/Near Threatened by the IUCN.
significance to humans
The maned wolf is usually uncommon with only minor significance to humans.
Canis thous (Linnaeus, 1766), Surinam. This species is quite similar to the more widespread genus of South American canids, Dusicyon, and has been included in the latter genus on several occasions. Molecular evidence is needed to resolve this issue. Fossil Cerdocyon from North America probably represent a colonization from South America. Five subspecies have been erected but are not well defined.
other common names
English: Common fox, forest fox; Spanish: Zorro comun, zorro sabanero, zorro perro.
A medium sized canid weighing about 11.0 lb (5 kg) (range: 6.6–19.8 lb [3–9 kg]), Cerdocyon has relatively short legs (second only to the bush dog amongst the canids in its ratio of fore-limb to body length). The hair is pale gray with black hair tips. A reddish tinge on the belly and flanks is also common. The skull dimensions best represent the average skull for the family falling in the middle of a multi-variate plot.
Crab-eating foxes occupy a large area of eastern South America from Venezuela in the north to northern Argentina in the south. They do not occur in the densest parts of the Amazon forests.
The species occupies a wide range of habitats. They are most common in "edge" habitats with a mixture of woodlands and open country. They can also survive in closed-canopy forests and grassland. However, they do not occupy more open country if Dusicyon gymnocercus, Azara's fox, is present in that habitat. They live in the seasonally flooded areas of Amazonia but not the thick forests.
The species is monogamous and pairs live in territories, which are marked by the pair with urine and feces. Territories can be as small as 0.2 mi2 (0.5 km2) and as large as 3.9 mi2 (10 km2) in less productive areas. In the seasonally flooded Llanos ranges shift and are less rigorously defended in the wet season when food is abundant. Pairs use a loud whistling vocalization to reunite.
feeding ecology and diet
The species forages at night and solitarily. They are omnivorous with a very varied diet. During the dry season in Venezuela 48% of the diet is vertebrates with 31% land crabs. During the wet season 54% of the diet is invertebrates, mainly beetles and grasshoppers, and small mammals make up 20%. Fruit and carrion form the remainder of the food. Frogs, lizards, mushrooms, and snails have also been found in stomachs.
Monogamous. Breeding occurs once a year in the wild, but is not strictly seasonal. (In captivity females can produce a litter every eight months, and reproduction does not seem to be tightly linked to patterns of daylight length.) Litter size varies from two to six with an average of four after a gestation of 52–59 days. Both parents provision the young and pups start to forage on their own around four months. Dispersal occurs from six to nine months.
The species remains widespread. It can colonize areas of cleared forest and can live close to human settlement. Like almost all canids it is hunted, but its fur is not useful.
significance to humans
The crab-eating fox is usually inconspicuous. It may kill chickens but is not of great significance to humans.
|Common name / Scientific name / Other common names||Physical characteristics||Habitat and behavior||Distribution||Diet||Conservation status|
|Arctic fox Alopex lagopus Spanish: Zorro polar||Two color phases, white and blue. Head and body length 18–26.6 in (45.8–67.5 cm), tail length 10–16.7 in (25.5– 42.5 cm).||Mainly in alpineand arctic tundra, usually in coastal areas. Makes den in low mounds with 4 to 12 entrances. Seasonal movements associated with food availability.||Circumpolar, entire tundra zone of the Holarctic, including most of the Arctic islands.||Any human food, dead or alive, carrion, marine mammals, invertebrates, sea birds, and fish. Predator of the ringed seal in winter and lemmings when on land.||Not threatened|
|Short-eared dog Atelocynus microtis Spanish: Zorro de orejas cortas||Upperparts dark gray to black, underparts rufous mixed with gray and black. Thickly haired, black tail. Head and body length 28.3–39.4 in (72–100 cm), tail length 9.8–13.8 in (25–35 cm).||Tropical forests from sea level to about 3,280 ft (1,000 m). Males dominant in most activities.||Amazon, upper Orinoco, upper Parana basins in Brazil, Peru, Ecuador, Colombia, and probably Venezuala.||Nothing is known about the food habits of this species in the wild. Observations suggest a carnivorous diet, although may eat fruit in the wild if prey is scarce.||Data Deficient|
|Side-striped jackal Canis adustus Spanish: Chacal de dorso franjeado||Coat is long, soft, partially mottled gray. Each side of body is lined with white hair, followed by line of dark hair. Underparts and tip of tail are white. Head and body length 25.6–31.9 in (65–81 cm), tail length 11.8–16.1 in (30–41 cm).||Moister parts of savannas, thickets, forest edge, cultivated areas, and rough country up to 8,860 ft (2,700 m) in elevation. Strictly nocturnal. Social groups are well spaced. Litters consist of 3 to 6 young.||Open woodland and semi-arid grassland from Senegal to Ethiopia, south to northern Namibia, northern Botswana, Zimbabwe, Mozambique, and northern South Africa.||Consists of various types of invertebrates, small vertebrates, carrion, and plant material.||Not threatened|
|Black-backed jackal Canis mesomelas Spanish: Chacal de lomo negro||Dark saddle on length of back to tip of tail. Sides, head, limbs, and ears are rufous. Underparts pale ginger. Slender build, very large ears. Head and body length 26.8–29.3 in (68–74.5 cm), tail length 11.8–15 in (30–38 cm).||Dry grassland, brushland, and open woodland. Basic social unit is mated pair and their young. About four young per litter.||Africa, south of the tropical rainforest in the west and as far north as Ethiopia and Sudan in the east.||An important predator of sheep.||Not threatened|
|Dhole Cuon alpinus Spanish: Dolo||Upperparts are rusty red, underparts pale, tail tipped with black. Head and body length 34.6–44.5 in (88–113 cm), tail length 15.7–19.7 in (40–50 cm).||Many types of habitat, but avoids deserts. Alpine areas, dense forest, and thick scrub jungles are a few. Hunts in packs. Five to 10 individuals within a pack.||Southern Siberia and central Asia to India and the Malay Peninsula, and on the islands of Sumatra and Java, but not Sri Lanka.||Mainly mammals larger than itself, including deer, wild pigs, mountain sheep, gaur, and antelope.||Vulnerable|
|Common name / Scientific name / Other common names||Physical characteristics||Habitat and behavior||Distribution||Diet||Conservation status|
|Falkland Island wolf Dusicyon australis Spanish: Zorro de las Malvinas||Upperparts are brown, some rufous and speckles of white. Underparts pale brown. Coat is soft and thick. Tail is short, bushy, tipped with white. Head and body length 38.2 in (97 cm), tail length 11.2 in (28.5 cm).||Found 250 mi (400 km) away from mainland, on islands. Very tame toward humans. Little is known.||Falkland Islands.||Consists mainly of birds, especially geese and penguins, as well as pinnipeds.||Extinct|
|Pampas fox Pseudalopex gymnocercus Spanish: Zorro gris mayor||Coloration is pale yellow, underparts and back are gray. Head, neck, and large ears are reddish. Muzzle is black. Long, bushy tail with two black spots. Throat and belly are whitish. Head and body length 24.4 in (62 cm), tail length 13.4 in (34 cm).||Pampas grasslands, hills, and deserts. They prefer plains and fields with tall grass, sierras, small narrow woods, and areas along streams.||Argentina, north of Rio Negro, Paraguay, Uruguay, southern Brazil, and eastern Bolivia.||Rodents of all kinds, birds, rabbits, frogs, lizards, fruit, and other vegetable matter like sugar cane stalks.||Not threatened|
|Culpeo Pseudalopex culpaeus German: Andenschakal; Spanish: Zorro colorado||Size increases the farther south the range is. Males are larger than females. Coloration is brownish tawny, underparts are paler. Back is gray, tail is tipped with black.||Pampas grasslands and deciduous forests of their range. Hierarchical matriarchal society. Mating period is from August to October. Strong hierarchical sense in social groups.||From Tierra del Fuego through the Andes of Chile and Argentina to the highlands of Bolivia, Peru, Ecuador, and Colombia.||Rodents and lagomorphs (rabbits and hares), as well as lambs a week old and younger.||Not threatened|
|Bush dog Speothos venaticus Spanish: Perro vinagre||Coloration is ochraceous fawn or tawny into dark brown or black on back and tail. Underparts are dark with a light patch on chin and throat. Stocky body, short, with broad muzzle. Tail is short. Head and body length 22.6–29.5 in (57.5– 75 cm), tail length 4.9–5.9 in (12.5– 15 cm).||Forests and wet savannas, often near water. Mainly diurnal, semi-aquatic. Litter of two to three individuals are produced during the rainy seasons.||Forested areas of Bolivia, Paraguay, and Brazil (except the semiarid northeast), eastern Peru, Ecuador, Colombia, Venezuela, Guyana, French Guiana, Suriname, and Panama.||Mainly large rodents.||Vulnerable|
|Gray fox Urocyon cinereoargenteus Spanish: Zorro gris plateado||Underparts are gray or white, ventral parts are rusty. Tail is tipped in black and the pelage is coarse. Head and body length 19–27 in (48.3–68.5 cm), tail length 10.8–17.5 in (27.53–44.5 cm).||Wooded and brushy country, often in rocky or broken terrain. Prefer pine-oak woodland bordering fields. Frequently climbs trees. Mostly nocturnal.||North America from Oregon, Nevada, Utah, and Colorado in the West and the USA-Canadian border in the East through Central America to northern Colombia and Venezuela.||Many kinds of small vertebrates, insects, and vegetable matter.||Not threatened|
|Island fox Urocyon littoralis Spanish: Zorro gris isleño||Underparts are gray, ventral parts are rusty. Head and body length 18.9–19.7 in (48–50 cm), tail length 4.3–11.4 in (11–29 cm).||Wooded and brushy country, often in rocky or broken terrain. Prefer pine-oak woodland bordering fields. Frequently climbs trees. Mostly nocturnal.||Islands off the Pacific Coast of southern California, United States.||Many kinds of small vertebrates, insects, and vegetable matter.||Lower Risk/Conservation Dependent|
|Tibetan fox Vulpes ferrilata English: Tibetan sand fox; Spanish: Zorro tibetaño||General coloration of upperparts is gray or sandy, underparts pale. Tip of tail is white. Head and body length 22.6–27.6 in (57.5–70 cm), tail length 15.7–18.7 in (40–47.5 cm).||Barren slopes and in stream beds at 9,840–13,120 ft (3,000–4,000 m) in the Mustang District of Nepal. Dens are made of boulders. Two to five young born a year.||China, in Tibet, Tsinghai, Kansu, and Yunnan; and Nepal.||Consists of rodents, lagomorphs, and ground birds.||Not threatened|
|Corsac fox Vulpes corsac Spanish: Zorro corsac||Fur is thick, soft, generally pale reddish gray, underparts are white or yellow. Head and body length 19.7–23.6 in (50–60 cm), tail length 9.8–13.8 in (25–35 cm).||Steppes and semi-desert. Lives in a burrow. Mainly nocturnal activity, but has been seen by day. Nomadic, does not keep fixed home range. Very social.||Kazakhstan, Russia, central Asia, Mongolia, Transbaikalia, north-eastern China, and northern Afghanistan.||Consists mostly of small rodents, but also pikas, birds, insects, and plant material.||Data Deficient|
|Swift fox Vulpes velox English: Kit fox; Spanish: Zorro veloz||Coloration of upperparts is dark buffy gray, underparts are buff to pure white. Coat is redder in summer. Head and body length 14.8–20.7 in (37.5– 52.5 cm), tail length 8.9–13.8 in (22.5– 35 cm).||Prairies, especially those with grasses of short and medium height. Builds burrows for shelter. Primarily nocturnal.||Central North America from southeastern British Columbia, south-central Alberta and southwestern Saskatchewan (Canada) to northwest Texas (panhandle) and eastern New Mexico, east of Rockies (United States).||Consists mostly of lagomorphs, as well as rodents, birds, lizards, and insects.||Lower Risk/Conservation Dependent|
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James Malcolm, PhD