GreyOwl Grand Teton National Park-

GreyOwl" Grand Teton National Park, a photo by chelseastarkphotography.com on Flickr.Via Flickr:Owlets begin growing their primary feathers (main, adult feathers) at 3 weeks of age. They have light yellow eyes with blue pupils. Less brooding is necessary and they are very active about the nest. Owlets learn to eject excrement (body waste) over the side of the nest but sometimes fall due to their clumsiness. About this time the owlets begin using a defensive display when disturbed. They raise their feathers, fan their wings downward, and hiss or snap their bill.After 5-6 weeks, the female coaxes the owlets out of the nest by offering food from a nearby branch. At about 9-10 weeks old the owlets first flight out of the nest to the ground. They quickly scramble up a tree to get away from ground level predators. If approached by a predator, they assume a hiding pose by sitting still and erect against the side of the tree. If this pose fails they present the defensive display. Feedings become irregular but the young owlets remain with the female and beg for food until September or October. During mid-June, the young owlets use their inborn instinct to attack prey. Young owls leave their parent's home range in autumn, when they are fully independent and can find their own hunting territory.When a member of the pair dies, the survivor remains in the home territory until another mate arrives.Owls defend their territories from other owls. Defense occurs during breeding times. It lasts from 1 month before breeding until the young owlets leave the parental territory. Adults may wander across territory lines for a short time before the next breeding season begins. They frequently allow other types of birds such as hawks to live in their territory. Owls with large territories frequently spend each season in a different part of their territory. Owls use specific areas of their territory for nesting and roosting. Some birds use certain trees so regularly that observers can predict in which trees they will find the owl in during a specific season. During the winter and fall, owls prefer evergreen roost trees since they provide daytime cover. When these are not available, owls will adapt to any place that provides as much concealment as possible during daylight hours. They seem to prefer to roost in isolated trees in small forest openings.