The pack will defend a territory from other packs, marking its boundaries with urine and howls. Solitary wolves are either young wolves looking for a new pack or, occasionally, wolves that were once head of a pack and have been ousted. A young male or female may search for a pack that has an ageing dominant pair and fight to take their position. Or a lone male may try to attract a female, to start a new pack. Solitary wolves have a hard time in winter, as it takes the strength of a pack to bring down a large kill.
Wolves only mate at certain times of the year, which vary between populations.
She feeds them for eight to ten weeks, after which they get food and attention from other pack members. The pups become sexually mature at about 2 years old. Because of the variations in climate, vegetation, human settlement and development, wolf populations are under varying degrees of threat. A few populations of grey wolves still exist in areas of continental Europe, but they are being killed, partly because they threaten livestock and partly because of old fears. Their habitat is being destroyed and broken up for development and agriculture.