I'd like to share some thoughts with you on a big change in the offing for the natural world around us this time of year: the beginning of the nesting season. I want to talk about those early-nesting native protected bird species. Yes, there are a half-dozen native birds that are nesting as you read this column.
The earliest nesting species is the great horned owl (Bubo virginianus). This is a very large native owl species that is known and heard by many folks who live outside urban areas. These owls stand up to 22 inches in height with a 54-inch wingspan. This amazing species belongs to the eagle-owl family and is a skilled predator of many different species of animals. Great horned owls are found from the tree line in the Arctic south to Argentina at the farthest tip of South America. This big owl starts its selection of a nest platform from the end of December into early January. Great horned owls do not build their own nests, but are entirely dependent on nest structures built by hawks, crows, ravens and magpies. They also nest in cutbank cavities here in the Columbia Basin due to a lack of nests and trees over large areas of the Basin. These raptors will not even repair or modify an old nest platform in disrepair.
The female owl lays four eggs, a day and a half to two days apart, as an insurance policy for survival of their most vigorous chicks. Twenty-seven days later the first chick hatches and is constantly fed, becoming the dominant sibling of the clutch. Two days after that, the second chick comes forth and is fed after the dominant chick. If there is a good prey base to be found, all the chicks will be fed in order of their hatching. If the prey base is restricted, only the first two chicks will be fed, while the last two starve and are booted out of the nest. These big owls are pragmatists and always attempt to replace themselves each nesting season. They are very protective of their territory and young.
A few more facts about great horned owls: Their long ear tufts have nothing to do with their ears, but are actually part of their camouflage to allow the owl to look like a busted-off branch. This owl species is an ambush hunter. Listen for them through the next three weeks as they call to each other. The male’s call is half an octave lower than the female.
The second early nesting species is the red-tailed hawk (Buteo jamaicensis), which is also a state- and federally protected species. This broad-winged hawk stands up to 22 inches high and has a 50-inch wingspan. This is the hawk that often has to take on the challenge from great horned owls for its nest. Here in the Walla Walla Valley we often find where these two big raptors alternate in using a nest platform from year to year. This hawk is a rodent- and serpent-hunter, and will take birds if the opportunity presents itself.
Red-tailed hawks are found across North America, with the darkest-plumaged birds coming out of northern Canada. The lightest-plumaged and smallest in size are found in the desert Southwest and northern Mexico. They lay four eggs and typically raise four chicks unless the prey base is low. This is typically the screaming hawk heard in Hollywood movies.
That is it for this month, Enjoy your weeks until we visit again.
Mike Denny is president of the Blue Mountain chapter of the National Audubon Society. He can be reached by email at firstname.lastname@example.org.