A coywolf is a canid hybrid descended from coyotes (Canis latrans), eastern wolves (Canis lycaon), gray wolves (Canis lupus), and dogs (Canis familiaris). All of these species are members of the genus Canis with 78 chromosomes; they therefore can interbreed. [1] One genetic study indicates that these species genetically diverged relatively recently (around 55,000–117,000 years ago). Genomic studies indicate that nearly all North American gray wolf populations possess some degree of admixture with coyotes following a geographic cline, with the lowest levels occurring in Alaska, and the highest in Ontario and Quebec, as well as Atlantic Canada. [2] Another term for these hybrids is sometimes wolfote.
Hybrids of any combination tend to be larger than coyotes but smaller than wolves; they show behaviors intermediate between coyotes and the other parent's species. [3] [4] In one captive hybrid experiment, six F1 hybrid pups from a male northwestern gray wolf and a female coyote were measured shortly after birth with an average on their weights, total lengths, head lengths, body lengths, hind foot lengths, shoulder circumferences, and head circumferences compared with those on pure coyote pups at birth. Despite being delivered by a female coyote, the hybrid pups at birth were much larger and heavier than regular coyote pups born and measured around the same time. [3] At six months of age, these hybrids were closely monitored at the Wildlife Science Center. Executive Director Peggy Callahan at the facility states that the howls of these hybrids are said to start off much like regular gray wolves with a deep strong vocalization, but changes partway into a coyote-like high pitched yipping. [5]
Compared with pure coyotes, eastern wolf × coyote hybrids form more cooperative social groups and are generally less aggressive with each other while playing. [6] Hybrids also reach sexual maturity when they are two years old, which is much later than occurs in pure coyotes. [7]
Eastern coyotes range from New England, New York, New Jersey, Pennsylvania, [8] Ohio, [9] West Virginia, [10] Maryland, [11] Delaware, and Virginia. [12] Their range also occurs in the Canadian provinces of Ontario, Quebec, New Brunswick, [13] Nova Scotia, [14] Prince Edward Island and Newfoundland and Labrador. [15] Coyotes and wolves hybridized in the Great Lakes region, followed by an eastern coyote expansion, creating the largest mammalian hybrid zone known. [16] Extensive hunting of gray wolves over a period of 400 years caused a population decline that reduced the number of suitable mates, thus facilitating coyote genes swamping into the eastern wolf population. This has caused concern over the purity of remaining wolves in the area, and the resulting eastern coyotes are too small to substitute for pure wolves as apex predators of moose and deer. [17]
The main nucleus of pure eastern wolves is currently concentrated within Algonquin Provincial Park. This susceptibility to hybridization led to the eastern wolf being listed as Special Concern under the Canadian Committee on the Status of Endangered Wildlife and with the Committee on the Status of Species at Risk in Ontario. By 2001, protection was extended to eastern wolves occurring on the outskirts of the park, thus no longer depriving Park eastern wolves of future pure-blooded mates. By 2012, the genetic composition of the park's eastern wolves was roughly restored to what it was in the mid-1960s, rather than in the 1980s–1990s, when the majority of wolves had large amounts of coyote DNA. [17]
Aside from the combinations of coyotes and eastern wolves making up most of the modern day eastern coyote's gene pools, some of the coyotes in the northeastern United States have mild domestic dog (C. lupus familiaris) and western Great Plains gray wolf (C. l. nubilus) influences in their gene pool, suggesting that the eastern coyote is actually a four-in-one hybrid of coyotes, eastern wolves, western gray wolves, and dogs. The hybrids living in areas with higher white-tailed deer density often have higher degrees of wolf genes than those living in urban environments. The addition of domestic dog genes may have played a minor role in facilitating the eastern hybrids' adaptability to survive in human-developed areas. [18]
The four-in-one hybrid theory was further explored in 2014, when Monzón and his team reanalyzed the tissue and SNP samples taken from 425 eastern coyotes to determine the degree of wolf and dog introgressions involved in each geographic range. [19] The domestic dog allele averages 10% of the eastern coyote's genepool, while 26% is contributed by a cluster of both eastern wolves and western gray wolves. The remaining 64% matched mostly with coyotes. This analysis suggested that prior to the uniformity of its modern-day genetic makeup, multiple swarms of genetic exchanges between the coyotes, feral dogs, and the two distinct wolf populations present in the Great Lakes region may have occurred. Urban environments often favor coyote genes, while the ones in the rural and deep forest areas maintain higher levels of wolf content. A 2016 meta-analysis of 25 genetics studies from 1995 to 2013 found that the northeastern coywolf is 60% western coyote, 30% eastern wolf, and 10% domestic dog. However, this hybrid canid is only now coming into contact with the southern wave of coyote migration into the southern United States. [20]
The taxonomy of the red and eastern wolf of the Southeastern United States and the Great Lakes regions, respectively, has been long debated, with various schools of thought advocating that they represent either unique species or results of varying degrees of gray wolf × coyote admixture.
In May 2011, an examination of 48,000 single nucleotide polymorphisms in red wolves, eastern wolves, gray wolves, and dogs indicated that the red and eastern wolves were hybrid species, with the red wolf being 76% coyote and 20% gray wolf, and the eastern wolf being 58% gray wolf and 42% coyote, finding no evidence of being distinct species in either. [21] The study was criticized for having used red wolves with recent coyote ancestry, [22] and a reanalysis in 2012 indicated that it suffered from insufficient sampling. [23]
A comprehensive review in 2012 further argued that the study's dog samples were unrepresentative of the species' global diversity, having been limited to boxers and poodles, and that the red wolf samples came from modern rather than historical specimens. [24] The review was itself criticized by a panel of scientists selected for an independent peer review of its findings by the USFWS, which noted that the study's conclusion that the eastern wolf was a full species was based on insufficient evidence — just two unique nonrecombining markers. [25]
In 2016, a whole-genome DNA study suggested that all of the North American canids, both wolves and coyotes, diverged from a common ancestor 6,000–117,000 years ago. The whole-genome sequence analysis shows that two endemic species of North American wolf, the red wolf and eastern wolf, are admixtures of the coyote and gray wolf. [26] [27]
In a study that analyzed the molecular genetics of coyotes, as well as samples of historical red wolves and Mexican wolves from Texas, a few coyote genetic markers have been found in the historical samples of some isolated Mexican wolf individuals. Likewise, gray wolf Y chromosomes have also been found in a few individual male Texan coyotes. [28] This study suggested that although the Mexican wolf is generally less prone to hybridizations with coyotes, exceptional genetic exchanges with the Texan coyotes may have occurred among individual gray wolves from historical remnants before the population was completely extirpated in Texas. The resulting hybrids would later on melt back into the coyote populations as the wolves disappeared.
The same study discussed an alternative possibility that the red wolves, which also once overlapped with both species in central Texas, were involved in circuiting the gene flows between the coyotes and gray wolves, much like how the eastern wolf is suspected to have bridged gene flows between gray wolves and coyotes in the Great Lakes region, since direct hybridizations between coyotes and gray wolves is considered rare.
In tests performed on a stuffed carcass of what was initially labelled a chupacabra, mitochondrial DNA analysis conducted by Texas State University showed that it was a coyote, though subsequent tests revealed that it was a coyote × gray wolf hybrid sired by a male Mexican wolf. [29]
In 2013, the U.S. Department of Agriculture Wildlife Services conducted a captive-breeding experiment at their National Wildlife Research Center Predator Research Facility in Logan, Utah. Using gray wolves from British Columbia and western coyotes, they produced six hybrids, making this the first hybridization case between pure coyotes and northwestern wolves. The experiment, which used artificial insemination, was intended to determine whether or not the sperm of the larger gray wolves in the west was capable of fertilizing the egg cells of western coyotes. Aside from the historical hybridizations between coyotes and the smaller Mexican wolves in the south, as well as with eastern wolves and red wolves, gray wolves from the northwestern US and western provinces of Canada were not known to interbreed with coyotes in the wild, thus prompting the experiment.
The six resulting hybrids included four males and two females. At six months of age, the hybrids were closely monitored and were shown to display both physical and behavioral characteristics from both species, as well as some physical similarities to the eastern wolves, whose status as a distinct wolf species or as a genetically distinct subspecies of the gray wolf is controversial. Regardless, the result of this experiment concluded that northwestern wolves, much like many other canids, are capable of hybridizing with coyotes. [3]
In 2015, a research team from the cell and microbiology department of Anoka-Ramsey Community College revealed that an F2 litter of two pups had been produced from two of the original hybrids. At the same time, despite the six F1's successful delivery from the same coyote, they were not all full siblings because multiple sperm from eight different northwestern wolves were used in their production. The successful production of the F2 litter, nonetheless, confirmed that hybrids of coyotes and northwestern wolves are just as fertile as hybrids of coyotes to eastern and red wolves. Both the F1 and F2 hybrids were found to be phenotypically intermediate between the western gray wolves and coyotes. Unlike the F1 hybrids, which were produced via artificial insemination, the F2 litter was produced from a natural breeding. [30]
The study also discovered through sequencing 16S ribosomal RNA encoding genes that the F1 hybrids all have an intestinal microbiome distinct from both parent species, but which was once reported to be present in some gray wolves. Moreover, analysis of their complementary DNA and ribosomal RNA revealed that the hybrids have very differential gene expressions compared to those in gray wolf controls.
Hybrids between coyotes and domestic dogs have been bred in captivity, dating to pre-Columbian Mexico. [31] Other specimens were later produced by mammal biologists mostly for research purposes. Domestic dogs are included in the gray wolf species. [32] Hence, coydogs are another biological sub-variation of hybrids between coyotes and gray wolves - the dog being considered a domesticated subspecies of Canis lupus. [33]
The coyote is a species of canine native to North America. It is smaller than its close relative, the gray wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecological niche as the golden jackal does in Eurasia. The coyote is larger and was once referred to as the American jackal by a behavioral ecologist. Other historical names for the species include the prairie wolf and the brush wolf.
Canidae is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid. The family includes three subfamilies: the Caninae, the extinct Borophaginae and Hesperocyoninae. The Caninae are known as canines, and include domestic dogs, wolves, coyotes, foxes, jackals and other species.
There are 38 subspecies of Canis lupus listed in the taxonomic authority Mammal Species of the World. These subspecies were named over the past 250 years, and since their naming, a number of them have gone extinct. The nominate subspecies is the Eurasian wolf.
The red wolf is a canine native to the southeastern United States. Its size is intermediate between the coyote and gray wolf.
The wolf, also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of Canis lupus have been recognized, including the dog and dingo, though gray wolves, as popularly understood, only comprise naturally-occurring wild subspecies. The wolf is the largest extant member of the family Canidae, and is further distinguished from other Canis species by its less pointed ears and muzzle, as well as a shorter torso and a longer tail. The wolf is nonetheless related closely enough to smaller Canis species, such as the coyote and the golden jackal, to produce fertile hybrids with them. The wolf's fur is usually mottled white, brown, gray, and black, although subspecies in the arctic region may be nearly all white.
Canis is a genus of the Caninae which includes multiple extant species, such as wolves, dogs, coyotes, and golden jackals. Species of this genus are distinguished by their moderate to large size, their massive, well-developed skulls and dentition, long legs, and comparatively short ears and tails.
A wolfdog is a canine produced by the mating of a domestic dog with a gray wolf, eastern wolf, red wolf, or Ethiopian wolf to produce a hybrid.
The eastern wolf, also known as the timber wolf, Algonquin wolf and eastern timber wolf, is a canine of debated taxonomy native to the Great Lakes region and southeastern Canada. It is considered to be either a unique subspecies of gray wolf or red wolf or a separate species from both. Many studies have found the eastern wolf to be the product of ancient and recent genetic admixture between the gray wolf and the coyote, while other studies have found some or all populations of the eastern wolf, as well as coyotes, originally separated from a common ancestor with the wolf over 1 million years ago and that these populations of the eastern wolf may be the same species as or a closely related species to the red wolf of the Southeastern United States. Regardless of its status, it is regarded as unique and therefore worthy of conservation with Canada citing the population in eastern Canada as being the eastern wolf population subject to protection.
The Ethiopian wolf, also called the red jackal, the Simien jackal or Simien fox, is a canine native to the Ethiopian Highlands. In southeastern Ethiopia, it is also known as the horse jackal. It is similar to the coyote in size and build, and is distinguished by its long and narrow skull, and its red and white fur. Unlike most large canids, which are widespread, generalist feeders, the Ethiopian wolf is a highly specialised feeder of Afroalpine rodents with very specific habitat requirements. It is one of the world's rarest canids, and Africa's most endangered carnivore.
The golden jackal, also called common jackal, is a wolf-like canid that is native to Eurasia. The golden jackal's coat varies in color from a pale creamy yellow in summer to a dark tawny beige in winter. It is smaller and has shorter legs, a shorter tail, a more elongated torso, a less-prominent forehead, and a narrower and more pointed muzzle than the Arabian wolf. It is listed as Least Concern on the IUCN Red List due to its widespread distribution and high density in areas with plenty of available food and optimum shelter.
A coydog is a canid hybrid resulting from a mating between a male coyote and a female dog. Hybrids of both sexes are fertile and can be successfully bred through four generations. Similarly, a dogote is a hybrid with a dog father and a coyote mother.
The Mexican wolf, also known as the lobo, is a subspecies of gray wolf native to southeastern Arizona and southern New Mexico in the United States, and northern Mexico. It once also ranged into western Texas. It is the smallest of North America's gray wolves, and is similar to the Great Plains wolf, though it is distinguished by its smaller, narrower skull and its darker pelt, which is yellowish-gray and heavily clouded with black over the back and tail. Its ancestors were likely the first gray wolves to enter North America after the extinction of the Beringian wolf, as indicated by its southern range and basal physical and genetic characteristics.
Canid hybrids are the result of interbreeding between the species of the subfamily Caninae.
The Japanese wolf, also known as the Honshū wolf, is an extinct subspecies of the gray wolf that was once endemic to the islands of Honshū, Shikoku and Kyūshū in the Japanese archipelago.
The Himalayan wolf is a canine of debated taxonomy. It is distinguished by its genetic markers, with mitochondrial DNA indicating that it is genetically basal to the Holarctic grey wolf, genetically the same wolf as the Tibetan and Mongolian wolf, and has an association with the African wolf. No striking morphological differences are seen between the wolves from the Himalayas and those from Tibet. The Himalayan wolf lineage can be found living in Ladakh in the Himalayas, the Tibetan Plateau, and the mountains of Central Asia predominantly above 4,000 m (13,000 ft) in elevation because it has adapted to a low-oxygen environment, compared with other wolves that are found only at lower elevations.
The eastern coyote is a wild North American canine hybrid with both coyote and wolf parentage. The hybridization likely first occurred in the Great Lakes region, as western coyotes moved east. It was first noticed during the early 1930s to the late 1940s, and likely originated in the aftermath of the extirpation of the gray wolf and eastern wolf in southeastern Ontario, Labrador and Quebec, thus allowing coyotes to colonize the former wolf ranges, and mix with the remnant wolf populations. This hybrid is smaller than the eastern wolf and holds smaller territories, but is larger and holds more extensive home ranges than the typical western coyote.
A jackal–dog hybrid is a canid hybrid resulting from a mating between a domestic dog and a golden jackal. Such crossbreeding has occurred numerous times in captivity and was first confirmed to occasionally happen in the wild in Croatia in 2015.
The Pleistocene wolf, also referred to as the Late Pleistocene wolf, is an extinct lineage or ecomorph of the grey wolf. It was a Late Pleistocene 129 Ka – early Holocene 11 Ka hypercarnivore. While comparable in size to a large modern grey wolf, it possessed a shorter, broader palate with large carnassial teeth relative to its overall skull size, allowing it to prey and scavenge on Pleistocene megafauna. Such an adaptation is an example of phenotypic plasticity. It was once distributed across the northern Holarctic. Phylogenetic evidence indicates that despite being much smaller than this prehistoric wolf, the Japanese wolf, which went extinct in the early 20th century, was of a Pleistocene wolf lineage, thus extending its survival to several millennia after its previous estimated extinction around 7,500 years ago.
The African wolf is a canine native to North Africa, West Africa, the Sahel, northern East Africa, and the Horn of Africa. It is listed as least concern on the IUCN Red List. In the Middle Atlas in Morocco, it was sighted in elevations as high as 1,800 m (5,900 ft). It is primarily a predator of invertebrates and mammals as large as gazelle fawns, though larger animals are sometimes taken. Its diet also includes animal carcasses, human refuse, and fruit. They are monogamous and territorial; offspring remain with the parents to assist in raising their parents' younger pups.
The evolution of the wolf occurred over a geologic time scale of at least 300 thousand years. The grey wolf Canis lupus is a highly adaptable species that is able to exist in a range of environments and which possesses a wide distribution across the Holarctic. Studies of modern grey wolves have identified distinct sub-populations that live in close proximity to each other. This variation in sub-populations is closely linked to differences in habitat – precipitation, temperature, vegetation, and prey specialization – which affect cranio-dental plasticity.