By Rick Baetsen The sight of a Great Gray Owl hunting prey in open fields is nature at its finest. This is a truly impressive bird. In a book about his research with this owl, Dr. Robert Nero, of Manitoba, Canada, describes the bird as the "Phantom of the Northern Forest." The Great Gray Owl is the largest in size of the North American owls, though the Snowy Owl is actually the heaviest in weight. The Great Gray Owl has a wingspan of 50-60" and has a perched height of 22-32". The female of the species averages slightly larger in size, than that of the male. As a whole the bird lives up to its name, and is of an overall gray color. This color can vary with some birds being a dark gray, some light gray, some a light brown-gray mixed color. A very light, almost white bird was observed on Sugar Island, Chippewa County, Michigan during the 1992 winter owl invasion. Dr. Nero reports that the females of the species tend to be a bit darker in color. It does have striated lighter colored feathers on the breast and also has a pattern of mixed darker and lighter colored feathers on the back and primary wing feathers. The owl has yellow eyes that are surrounded by large facial disks. The feather pattern and density of the feathers in this disk, serve to funnel or channel the sounds collected in the disk to the owls ears, that are located on the external edges of the facial disks. The disk composed of alternating rings of dark and light feathers and other than the owls piercing eyes, is most likely one of its most noticeable features. There is white feathering on each side and underneath the owl’s beak, which sometimes makes it appear like the owl is sporting a mustache. The bird’s call is that of a series of very low toned "whooo’s". As in many of the other owls, the birds call is rarely heard outside of the springtime courtship period. Much of the year the birds remain silent. In North America, the Great Gray Owl is known to be a breeding resident of Alaska, much of Canada, the higher elevations of the Rocky Mountain States, northern Minnesota and recently northern Wisconsin. Breeding evidence has been noted in Michigan in Chippewa County, on Neebish Island in 1981, by Jensen, Robinson, and Heitman. After the major Great Gray Owl invasion during the winter of 1992, a number of birds were observed throughout the next two years on Sugar and Neebish Islands and within the boundaries of the Hiawatha National Forest, of Chippewa County. Breeding evidence of the Great Gray Owl was again noted on Neebish Island in July of 1994. Don and Betty Tucker observed an immature Great Gray Owl on their property several times, also being tended by the adult bird. I had the chance to observe and film this immature bird. The immature bird was developing feathers, but it was still covered with many downy feathers. It was capable of very limited flight of 30-60 meters. I presented the photos and descriptions of this immature Great Gray Owl to researchers, Dr. Robert Nero and Dr. Jim Duncan at the 2nd International Symposium on Biology and Conservation of Owl of the Northern Hemisphere, in Winnipeg, Manitoba, Canada, in February of 1997. Dr’s Duncan and Nero determined that the young bird had been hatched and raised and fledged on Neebish Island. No nest was ever located, but once again there is evidence that the Great Gray Owl has nested in Michigan. The image included in this profile of this young Great Gray Owl was taken on Neebish Island on July 27, 1994. The breeding habitat of the Great Gray Owl is that of the boreal forest and tamarack bogs. This habitat, much of which is in Canada, is found south of the tundra and north of the "deciduous" or leafy tree forests found further to the south. In areas of the western States where it breeds, it is found in the dense conifer forests of the higher elevations. As spring approaches the male prepares for breeding and nesting season by doing aerial displays and it brings food to the female. The birds search for a nesting site after they pair bond. They do not build their own nest, but rather take over an abandoned nest of other bird species, or often use the tops of tree snags. The nest is usually from 15-45’ in height from the ground. Nesting occurs in late spring and the female lays and incubates from two to five eggs for about 30 days. The male bird brings food to the young and female after the young have hatched. The young leave the nest about 30 days after hatching, but remain in the nest territory for up to another two months. The owl has one brood of young per year. Like that of most owls, even those of the largest owl species, the prey of this owl is almost exclusively of small rodents, of voles and mice. Many of the owl species are "nocturnal", meaning that their activities are limited to the cover of darkness. The Great Gray Owl and a couple other northern owl species have a need to be able to hunt during the daylight hours. The daylight hours of the summer days are long in the far north. It is this "diurnal" or daylight feeding habitats that make this owl so visible during its winter invasions. The owl sits upon a high perch and uses its keen hearing and vision to locate voles or mice on top or even underneath the snow cover. The bird takes to flight upon nearly silent wings and using sharp talons, takes prey from the snows surface. They also use a technique called "snow plunging" and this is where they have located prey under the snow’s surface. They plunge head and talons into the snow cover to capture prey under the snow. The owls will make major movements south from its normal range in the years when the owl’s main prey of the voles is in short supply. This is not considered to be a true migration, but is more of a southward invasion in search of prey. In the recent past these invasions have occurred in 1978, 1984, 1992, 1996, 1997. The best-known recent invasion was in 1992 when over 60 of the Great Gray Owls showed up in late January to areas of Michigan’s eastern Upper Peninsula. Large numbers of the birds showed up again during the hard winters of 1996, and 1997. Great Gray Owls were located in Michigan’s lower peninsula during the 1997 invasion, with reports of birds coming from Harbor Springs, East Jordan, and Grayling areas. During the invasion years, the eastern area of Chippewa County, including areas of Sugar and Neebish Islands and areas south and east of the city of Sault Ste. Marie, provide the best areas to search for these owls. Search for them in abandoned farm fields that have some trees or brush to provide observation perches for the birds. These same fields often have dense grasses that hold higher numbers of the prey species. Look for them on the tops of trees, utility poles, barns or even the fence posts along the edges of roads. The birds can be seen on perches at any time during the day, but they are more likely to feed in the early mornings or late afternoons. Keweenaw County, MI; April 1996 As of this writing in late January of 2000, there are yet no reports of any Great Gray Owls or Northern Hawk-owls in the Eastern Upper Peninsula of Michigan. The first of the Snowy Owls were reported from Chippewa County on January 25th, so there is a chance that other northern owls could still arrive this winter. The Great Gray Owls arrived during the first week in February, in the 1996 invasion year. The photos used to illustrate this profile were all taken in Chippewa County, Michigan, unless otherwise noted. Good reading on the Great Gray Owl can be found in the following books: The Great Gray Owl- Phantom of the Northern Forest by Dr. Robert Nero Lady Grayl: Owl with a Mission by Dr. Robert Nero The Great Gray Owl- On Silent Wings by Robert Taylor All images & text in this Northern Michigan Birding Bird Profile are owned by Rick Baetsen. Rick specializes in nature photography and his photographs can be purchased online at Rick Baetsen Wildlife & Nature Photography