One quantitative and nine qualitative genetic markers were investigated in some 200 individuals of the family Canidae, including 34 breeds and species. A high degree of homogeneity was observed and only one marker, transferrin, displayed marked variation. The consistent differences were: wolf (one sample), transferrin; jackal (one sample), transferrin and glucosephosphate isomerase; foxes, albumin, transferrin and glucosephsophate isomerase. Two abnormal transferrins were observed in two siblings among six German short-haired pointers. All other markers were homogeneous, usually single protein species or multiple forms dispersed randomly through the group. The results suggest that domestic dogs and dingoes share a common pool of genes and that all canids but the foxes possess many genes in common. There are indications that the jackal and wolf may differ from other canids in some marker systems.

A total of 838 foxes were collected throughout New South Wales from 1969 to 1974. In every month of the year there were some males producing sperm but there was a major peak of activity during June, July and August. The major period of female reproductive activity commenced in July and reached a peak in August. There were indications that some females ovulated during February and March although no pregnancies were recorded outside June-October. At least 30 % of vixens suffered preplacentation loss of ova or blastocysts, but an accurate estimate was impossible because of an apparently high incidence of polyovuly. Resorption accounted for the loss of 8 % of embryos from 35 pregnant females. A mean litter size of 4.0 was calculated from pregnancies; the mean number of placental scars was 3.7; three deformed embryos were found. The proportion of juvenile animals in the sample decreased from January to the beginning of the breeding season. The weight of the eye-lens was unsuitable for differentiating between yearling and adult foxes in this type of sample.

In Kinchega National Park, where there is no domestic stock, stomachs were examined of 99 foxes; there was food in 95 of them. Food was mainly rabbits except in autumn, when it was mainly insects and centipedes were an important item. Occurrence and relative importance of other foods are discussed.