Status Least Concern
Size Height: 57–67 cm
Weight Males 568–1110 g; females 977–1900 g
Gestation 28-36 days
Young 2-9 eggs are laid
Life span Up to 27 years
Great grey owls mainly eat small mammals, especially rodents. They also eat small birds and occasionally frogs and large insects. These owls swallow smaller prey whole, and pull larger prey to pieces first.
Great grey owls are found in many countries in the northern hemisphere, including the US, Canada, China, northern Europe and Russia. They live in a variety of forested habitats, including boreal and coniferous, preferring areas that have breaks in the forest, such as bogs, open fields, and meadows. They mainly forage at the edge of forests or in open areas.
Great grey owls lay their eggs in a variety of makeshift nests, such as the abandoned nests of other birds of prey, the forks of large branches, mistletoe, and even shallow depressions at the base of trees or artificial nest platforms. They may nest up to 30 metres off the ground. Females incubate the eggs, and the males come to the nest to feed them. The female will only leave the nest to defecate and to regurgitate pellets. The young leave the nest at 25 to 30 days of age, when they are still unable to fly. Instead, they will climb leaning trees to roost off the ground until they are able to fly a week to two weeks later. These owls usually start to breed at three years of age.
Little is known about the predators of these birds, but nesting great grey owls are known to attack black bears and drive off northern goshawks that enter the nest area, suggesting that these species are predators of the young.
This species does not currently face any major threats, and its population size is thought to be increasing. However, great grey owls may face a number of threats in some places, including from hunting, loss of habitat and collisions with traffic, power lines and cables.
Great grey owls hunt from their perch. They listen carefully and watch the ground, then when they detect their prey they fly up to 100 m to strike it.
The abundance of food within the habitat of the great grey owl can have an effect on the number of eggs they lay.
These owls have such excellent hearing that they can hear their prey underneath the snow. They will plummet into the snow with their feet clenched. They can break though a crust of snow that is hard enough to support an 80 kg weight, and that may be as deep as 45 cm!
We rely on day ticket, retail and catering sales; things we are no longer receiving; in order to operate.
You can help us through these difficult times...
This was my second visit to Marwell with my grandson, he’s 9mths old. He had a ball on the train & was so excited to listen to the other children enjoying the ride. I’ve brought an annual pass, as I wanted to spend some quality time with him. Feeling a bit… Read full reviewDonna, 23rd May 2018