The Northern hawk-owl (Surnia ulula) is a nocturnal bird of prey. It lives in all the boreal countries, from America to Siberia, passing through northern Europe. Closely linked to forest life, it lives in the taiga forests, without therefore venturing into the tundra prairies. Its name in Italian comes from its cry that seems like a howl, while in English it is called hawk-owl (falco-gufo) for its rapid flight, its long tail, short wings and its streaks, which make it resemble a diurnal bird of prey. The species is not considered at risk, but the real state of conservation is unclear, due to the vastness of the territories in which it lives. It nests in the cavities of mature and ancient trees, for this reason the protection of ancient forests is very important, considering the fact that in all the countries where it lives, forestry activity is intensive.