DISTRIBUTION AND GENETICS OF THE COLOR PHASES OF THE RED FOX IN CANADA

Abstract

H E colored fox (Vzclpesfulva) and its geographic races exists throughout T most of its range in three main color phases: (I) The red fox is reddish brown to yellow with black markings on the feet and the ears. There is an area of pure white hairs on the mid-ventral line and on the tip of the tail. (2) The silver fox has all the reddish brown hairs replaced by black ones or black with a white band. The width of the band and the distribution of the white-banded hairs determines whether a fox of this phase is a black, one-quarter silver, three-quarters silver, etc. Most of the farmed foxes have been selectiveIy bred so that from three-quarters to the whole of their body is covered with these silvery hairs. The pure white portion of the body remains unchanged. I n farmed types such as white faces, ring neck and platinums this white area has been much enlarged. (3) The cross fox is a mixture of the other two types. There is a great deal of variation in foxes of this type. A typical specimen has red flanks, shoulders and cheeks, and silver or black back and neck. The darkened lengthwise line down the back and the dark fur on the neck form a cross from which the animal derives its name. Some foxes are very similar to the red phase but have a smoky appearance because of the number of black hairs scattered through the pelt. These are spoken of in the trade as bastard foxes. Breeding experiments a t the HUDSON'S BAY COMPANY fur farm indicate that these foxes are similar to cross fox in their two main coat color factors. The fox population fluctuates markedly, with peak numbers every ten years in most of its range' and every four years in northern Quebec and Labrador. The population has increased over IOO per cent in the past 2 0 years. The peak years do not coincide in different parts of the country. There is migration from areas of high density, as witnessed by the appearance of runs of northern or western types of fur in places where they are not native. GENETICS OF THE COLOR PHASES Early in the history of fur farming it was observed that silvers appeared in the progeny of cross fox parents, and soon a mono-factoral hypothesis was proposed as follows: Red, SS; Cross, Ss; Silver, ss. Later ILJINA (1934, 1935) proposed a slightly more complicated system with a modifier making different types of cross as follows: Red, rr; Smoky red, Rr dd; Cross, Rr Dd; Cross, Rr DD; Silver, RR. As more animals were raised in captivity, it was found that the above The writer wishes to acknowledge the helpful suggestions and criticisms received from Dr.