Great horned owls are resident here year long. Their down feathers protect them from the cold and they eat
almost anything so it is very rare that they can not find prey. Staying around during the winter provides them with the advantage of nesting early. Here in Minnesota they are often on the nest by the end of January. This allows the young owls to have time to grow large enough to defend themselves before many of the other avian predators return to the area. It also helps in finding a nest. Great horned owls do not make their own nest so they have to borrow one, usually from a hawk, heron, or squirrel. Since most hawks and herons do not return that early in the year the owls often have a number of empty nests to chose from. The second photo is of a GHO chick branching. Before they can fly young GHO will climb around the branches of the tree where the nest is located. Sometimes they fall, but the parents will still feed and care for the chick on the ground. Unless a person comes by and finds them and takes them home. If they keep them for too long the owl will be imprinted and will not be able to be returned to the wild. So if you find a chick the best thing to do is to leave it be. If it looks injured or like it might be in danger from ground predators (coyotes, fox, raccoon house cats) then take it to a rehab facility. Most facilities will give it any care it needs and then return it to the nest if possible, that is what they do at The Raptor Center.