Canis familiaris × Vulpes vulpesAn alleged dog-fox hybrid (From: Walsh 1859, p. 165)
EUGENE M. MCCARTHY, PHD GENETICSGoogle+ Profile
Although throughout much of the Northern Hemisphere extensive natural contact does occur between fox and dog, nearly all reports of hybridization of this type refer to crosses in captivity involving a male fox and a bitch (one seemingly reliable French report does describe two such hybrids shot by hunters). This hybrid is sometimes known as a “dox.”
There is controversy over whether this cross actually occurs, and it is not very well documented. In particular, there seem to be no genetically verified cases on record. Moreover, since dogs are so variable, naysayers can always claim that any putative hybrid falls within the range of variation of ordinary dogs. The chromosome count of a red fox is 2n=34 (plus 3-5 micro-chromosomes) and that of a dog, 2n=78. So the difference in counts is large, with dogs having more than twice as many.
Nevertheless, Wilhelm Niemeyer, Director of the Hannover Zoological Gardens, does give what appears to be an authentic account (since it took place under strictly controlled conditions in captivity). In the 19th century, when Niemeyer reported this cross, it was normal practice at zoos to produce hybrids intentionally. For this reason, keepers at the Hannover Zoo arranged a mating between a dog and a captive fox. Niemeyer (1868, p. 69) says that “the fox, which was otherwise very tame, became fierce when the bitch, which was in heat,
was placed in his cage, and to calm him somewhat, the dog was chained in a corner. Gradually, the fox seemed to get used to its new companion and approached her ever more closely until after three hours, mating began. The bitch was thereafter kept strictly away from other dogs, and produced a litter of four young, one of which was dead at birth. The others died during the next few days. They were similar in color to the dark gray of the mother. [Translated by E. M. McCarthy. Original German.]
Beyond the fact that this case occurred in captivity and was reported by the head official of an important zoo, Niemeyer’s report seems authentic because the hybrids described were inviable. In many types of crosses, a relatively small percentage of the hybrid offspring are sufficiently viable to reach adulthood.
Another seemingly credible account, entitled Fox and Dog Hybrids near Horncastle, is given by the Rev. J. Conway Walter in the April, 1899 issue of The Naturalist: A Monthly Journal of Natural History for North England (p. 104), which reads as follows: “I exhibited, when the Lincolnshire Naturalists’ Union met in Holbeck and Tetford, in August 1897,
a case containing two stuffed specimens of a cross between a fox and dog, bred by Mr. Stafford Walker, of Horncastle, the sire being a male Fox (Vulpes vulpes) and the mother a half-bred bitch between Shepherd Dog and Whippet; of a litter of six only one survived. The mother was bought by the French savant, M. M. Suchetet [in that day, one of the world’s foremost authorities on hybrids], with a view to further experiments. Since then, several similar hybrids have been produced in this neighbourhood. In one case, at Ashby Puerorum, a farm bailiff, named Cross, tied his Shepherd bitch near a fox-earth; and the one pup reared is now in the possession of Mr. Frank Dynioke, of Scrivelsby Park. In another case, a gamekeeper near Louth tied a bitch in a wood, in the nutting season, to give warning of trespassers, and subsequently the bitch had pups, evidently a cross with Fox. One of these is now in the possession of Mr. Waltham, dealer in china, High Street, Horncastle. Another is in the possession of Mr. E. Walter, farmer, of Hatton, a cousin of Mr. Stafford Walter, who bred the original hybrids, which I exhibited in 1897.
Heinrich Heck (1932), the director of the Hellabrunn Zoo in Munich, Germany, describes a hybrid between a female spitz and a male fox as reddish in color, but not so red as a fox (Darwin, 1868, vol 1, p. 31, states that “the Spitz-dog in Germany is said to receive the fox more readily than do other breeds.”). It had the gracile build of a fox, a similar gait, and the same restlessness. The long, fine hair of the shaggy coat showed the mother’s influence.
Another article was written by British zoologist Reginald Innes Pocock (1900):
Hybrid Dog and Fox.—In the new Museum at Worcester, standing upon a shelf in the recess set apart for local mammals, there is a stuffed animal, labelled Wolf, which I suspect is a hybrid between a Dog and a Fox. Pasted up alongside is an old, and I think, dateless newspaper cutting, containing a sensational account of the behaviour of the 'monster’ during the time just preceding its destruction. The paragraph was too long to copy in full during the time at my disposal, but to the best of my recollection the pith of it is as follows: The animal entered a cottage in a village in Worcestershire, and quietly laid down under a table. Roused from its rest by the crying of a child, it was making for the sound with the purpose of devouring its originator, when a Cat, with less discretion than is usually displayed by this feline, flew at the intruder, but in the tussle that ensued was torn limb from limb and afterwards devoured piecemeal on the spot. The subsequent proceedings I forget, but the 'Wolf’ apparently continued to hang about the cottage, till some passing labourers, apprised of its doings and probable intentions, attacked and killed it. The alleged ferocity and unmistakable, albeit superficial, Wolf-like aspect of the animal, coupled may be with the circumstance that it was not recognized as the property of any of the farmers or Dog-owners of the neighbourhood, seem to have been the considerations which led the good people into whose hands the beast fell to settle offhand that it must be a 'Wolf escaped from a menagerie’ … Judging from the size of the teeth, the creature was adult. It is rather larger than a Fox, and has a bushy tail and erect ears. The legs and the head, so far as could be seen, except for a blackish patch in front of the ear, are a rich fawn-colour; the back is black, mottled with dark grey, the tail being much the same shade on the back, and without a white. Apart from its slightly superior size, it differs strikingly from a Fox in having the ears and feet fawn instead of blackish, and in the absence of white from the lips and throat. Of Wild Dogs, it is perhaps the Black-backed Jackal that it most calls to mind, although much stouter in build and smaller in the ears than that elegant species. It also resembles a small cock-eared colley, and might pass muster as such amongst a crowd of mongrels. A suspiciously 'foxy’ look about the beast, however, inclines me to the belief that it is the progeny of a Fox, and probably some country Sheep-dog.
Accounts of fertile fox-dog hybrids
John Henry Walsh F.R.C.S. (1810-1888) was an English surgeon and sports writer who wrote under the pseudonym "Stonehenge." In his book, The Dog in Health and Disease (Walsh 1859, p. 165), he comments that “it will be perhaps interesting to allude to the best authenticated specimen [of fox-dog hybrid] within my knowledge, which is now the property of Mr. Hewer of Reading. [This animal is pictured at the top of this webpage.] She is a daughter of the first cross which was described by Mr. Tomlin in ‘Bell’s Life’ in the year 1855, and is by an ordinary terrier dog.” He then goes on to quote Tomlin at length:
In 1853 various accounts appeared in ‘Bell’s Life in London’ of the fox and dog cross, the fact being established by a gentleman of Kent, who then possessed a vulpo-canine bitch which had produce by a dog (vide ‘Bell’s Life,’ Dec. 1853 and Feb. 1854). This bitch (half fox, half dog), now in my possession, had produce in the month of February last by a terrier dog. The produce are two dog-whelps and three bitches, some of which were (to ease the dam) suckled by a cur bitch. Two of the litter prove in nature shy as a fox; three of them dog-like in appearance, colour, and perfectly quiet, and follow well at heel. Still, they have the real fox muzzle and ‘fox action,’ about which (to those who have well studied it in the hunting-field) there exists but little mistake. Many there are who doubt the existence of any such animal as that between fox and dog. I am, however, in perfect condition to prove (by the living articles themselves) that the fox is merely a separate species of the genus dog, and intercopulates with the bitch, producing not a hybrid or mule animal, but one which will propagate its species.
Heck (1932) also says that a male fox-dog hybrid produced offspring with a female grey wolf (Canis lupus). Prichard (1836, p. 141) says, “Pallas (N. Nord. Beyträge) gives from Pennant two instances of generation between the dog and wolf and one between the dog and the fox, in which last the offspring, a female, afterwards produced young by a dog.” Herbert (1837, pp. 339-340), too, gives an eye-witness account of a fertile hybrid. He states that “I have lately had under my observation a dog, whose father was a fox in an innyard at Ripon, and it has singularly the manners as well as the voice of a fox, but it is the parent of many families of puppies.” Eiffe (1892) provides yet another account, entitled Fox Hybrid:
In the summer of 1886, I saw on a farm in Collow in Lauenburg a female fox hybrid from a shepherd dog and a wild fox. It had the size, shape and hair of a fox, but it differed from a red fox in that its coloration was more like that of a wolf, as shepherd dogs are generally colored. At the time, the hybrid had young by a domestic dog, which were black. It follows from this, then, that fox hybrids are fertile. In the neighborhood many shepherd dogs have a fox-like character, so that people can probably be believed who say the farmers there take their shepherd bitches to the woods when they are in heat to allow them to mate with foxes and thereby obtain more watchful and lively dogs. [Translated by E. M. McCarthy. Original German.]
Fox-dog hybrids in antiquity
Fox-dog hybrids have been a topic since ancient times. They are mentioned by Aristotle (De Generatione Animalium, Bk. II, Ch. 4) and by Galen (De Semine, Bk. II, Ch. 1), among others. According to Platt (p. 241), Aristotle believed the “Laconian hound,” an ancient breed of dog, to be derived from hybridization between fox and dog. And Xenophon (On Hunting, iii) says,
The Vulpine is a hybrid between the dog and the fox: hence the name. In the course of time the nature of the parents has become fused.
Most shared on Macroevolution.net:
Domestic Dog x Red Fox - © Macroevolution.net