Rain and wind may affect hunting success. A study in Italy showed that heavy snowfall caused the diet to switch from rodents to birds. Prey is killed by biting the back of the skull, after which the prey is often swallowed whole. Long-eared owls sometimes leave some parts of the prey uneaten, such as entrails or wings of birds. The duration of pair-bonds is unknown.
Male courtship involves advertising songs and a zigzagging aerial display.
The female responds by crouching with wings drooped. Copulation lasts about 3 seconds. They may preen one another's head area immediately before or after copulation. The long-eared owl mostly nests in trees, using abandoned stick nests of other species. Occasionally they may build a nest of their own, or use one located in such odd places as as an old tree stump or on the ground, but this is not the common practice.