Species portrait: European wolf
The wolf is the largest member of the canid family (Canidae). Body size and weight can differ considerably within the species Canis lupus. The largest wolves live in North America. Their weight is up to 80 kg, while their smaller relatives from the Arabian Peninsula only reach 15 kg. Data collected by LUPUS Institute and IZW on dead and captured wolves show medium values for Germany: adult females (older than 2 years) were between 25 and 35 kg, adult males weighed 33 to 43 kg. The span was even larger in yearlings (wolves in their second year of life): female yearlings were between 22 and 36 kg, male yearlings weighed 25 to 47 kg (as of April 2017).
In comparison with German Shepard dogs, wolves are much more long-legged and have a straight dorsal line. The ears appear relatively small, especially in winter fur, have a triangular shape and are thickly furred even on the inside. The brushy tail usually hangs down. The summer coat makes wolves look slenderer and even more long-legged. European wolves have a grey colour basis, which can vary from yellowish grey to greyish brown and dark grey. The bottom side of the snout and throat have a lighter colour and the back of the ears are reddish. Behind the shoulder blades there is a lighter saddleback, which is limited by a dark line. In many cases, the tip of the tail is dark. Many, but not all wolves have black markings on the front side of the front legs. The wolf’s body type is characteristic for a long-distance runner that can cover distances of many kilometres in a steady trot effortlessly. The wolf typically uses the direct register trot by placing the hind paws exactly into the print of the respective front paw. Like all canids, wolves have five-toed front paws and four-toed hind paws. However, only 4 toes and the pad leave prints.
Wolf sculls are long and wide, the volume of the brain is significantly larger than that of equally-sized domestic dogs. The wolf’s permanent dentition has 42 teeth (I:3/3, C:1/1, P:4/4, M:2/3). Tooth replacement takes place between the 5th and 7th month of life. In captivity, wolves can reach an age of 16 years and more. Most free-ranging animals die significantly earlier. One female wolf in Saxony reached an age of 13 years, which is a rare exemption.
Wolves live together in families (packs), which are usually composed of the two parental animals and their offspring from the last two to three years. Young wolves usually leave the parental territory with 10-22 months of age in order to search for their own area and mating partner. Therefore, in most packs the two parents are the only wolves that are permanently present in the territory.
Some young wolves stay in the parental territory for longer, in rare cases up to 4-5 years. As sexual maturity in wolves usually starts with an age of 22 months, it is possible that in such packs there are more animals capable of reproduction than the parental individuals. This can lead to the situation that female offspring reproduces in the pack as well as the parents. In free-ranging wolf packs, there is no highly competitive hierarchy like in wolves that live in captivity. In contrast to female domestic dogs, female wolves are in season only once a year, which is in winter. Following a pre-mating period of up to several weeks, mating takes place in late January or early March. After a gestation period of about 63 days, usually 4 to 6 pups are born in late April or early May. After 6 to 7 months, they have almost reached the size of the parents and yearlings (wolves in their second year of life) and join the other pack members.
Every pair of parents claims their own territory, which they defend against other wolves in the age of sexual maturity. Due to their strong territoriality, comparatively few wolves live in a large area. Territory size is mainly influenced by food availability. Every wolf territory has to be large enough so that the parents can find enough prey every year in order to raise their pups. The fewer prey animals are available in a region, the larger the territories have to be. Studies in central Europe have identified common territory sizes between 100 and 350 km2. Thus, wolves are spatially organised in a way that aims at sustainable use of their food resources. First results from radio-collared wolves show that the presence of refuges in the intensively used cultural landscape is also relevant for the location and size of territories.
In general, the wolf’s position in the trophic pyramid is on the top. The number of wolves in an area is solely determined by food availability and, if applicable, by diseases, but not by a superior predator. Equally, wolves naturally influence the number of wild ungulates as their antagonist. Wolves are specialised for hunting even-toed ungulates (Artiodactyla). In central Europe, they mainly feed on roe and red deer, wild boar, and locally on fallow deer and mouflons. In Scandinavia, moose and reindeer are their main prey species. In southern Europe, where wild ungulates are missing, domestic animals and rubbish can be a substantial part of their diet.