A black wolf is a melanistic colour variant of the gray wolf (Canis lupus). Black specimens are recorded among red wolves (Canis lupus rufus), and these color variants are probably still around today. Genetic research from the Stanford University School of Medicine and the University of California, Los Angeles revealed that wolves with black pelts owe their distinctive coloration to a mutation which occurred in domestic dogs, and was carried to wolves through wolf-dog hybridization. Besides coat color they are normal gray wolves.
Linnaeus gave the black wolves of Europe the binomial name Canis lycaon, under the assumption that the species was distinct from grey and white coloured wolves. Cuvier and other naturalists largely followed his example. Black wolves were considered rare in France, but common in Southern Europe at the time, with black wolf populations south to the Pyrenees apparently outnumbering other color morphs. They also occurred in the mountains of Friuli (Italy) and around Kotor (Montenegro). Black wolves were also reported in Siberia as the Vekvoturian Mountain-wolf.Colonel Smith erroneously believed that the so-called "Rossomak" of the Lenas in Siberia was of the same variety. However, in fact, "Rossomak" in Russian exactly corresponds with the English "wolverine", a mustelid species, in English (Gulo gulo in Latin). Black wolves were considered rare in northern Europe, however, Dr Höggberg, a medical practitioner at Karlstad mentioned five black wolves being killed in the Swedish province of Värmland in 1801. These wolves were completely black and were bigger than the more common grey variety. Their pelts were considered exotic enough to be sold for 3–4 times the price established for more common colour morphs. Also, the last wolf in Scotland, supposedly killed by MacQueen of Pall à Chrocain is usually narrated as having been black. Cuvier noted that European black wolves differed little in size from other colour morphs, but exceeded them in physical strength.Charles Hamilton Smith wrote that black wolves were generally less aggressive than ordinary kinds, and interbred with dogs more readily. In Serbia (South-Eastern Europe, Balkan peninsula) indicated that on 17.11.2012, a black wolf was killed at Stara mountain.