Decorah, Decorah North, Great Spirit Bluff
Great Horned Owls are non-migratory and live in the Decorah area year-round. They eat an enormous variety of prey, including rabbits, hares, mice, voles, shrews, chipmunks, a variety of squirrels, bats, skunks, domestic cats, ducks, loons, other owls, ravens, doves, and starlings – just to name a few! They supplement their diet with reptiles, insects, fish, invertebrates, and carrion.
Great Horned Owls usually adopt a nest that was built by another species, but they may also nest in natural cavities. They line their nest with shreds of bark, leaves, and downy feathers plucked from their own breast. Since Great Horned Owls do not build or replenish nests beyond lining them, their nests tend to deteriorate over the course of the breeding season. They do not usually re-use nests.
Egg laying may begin between late January and go through early March, with most eggs laid in February in our latitude. Great Horned Owls one to four white eggs per clutch and produce one clutch per year. Females incubate eggs for 30-37 days and provide most of the care for the young, while males provision the family with food. Young leave the nest around 42 days after hatching. To learn more, visit Cornell’s website.
Great Horned Owls are able to incubate eggs successfully when outside temperatures are below -28°F/-33°C. Like Bald Eagles, Great Horned Owls don’t constantly sit their eggs, even in very cold weather. Eggs in one nest withstood the female’s absence for 20 minutes when she joined her mate to hoot at a neighboring male. The temperature was -13°F/-25°C.
Bird Range Maps of North America
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003.
Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA. Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy – Migratory Bird Program, Conservation International – CABS, World Wildlife Fund – US, and Environment Canada – WILDSPACE.
Web Link: http://bit.ly/2ynPQ5I
Johnsgard, P. A. 1988. North American owls: biology and natural history. Washington, D.C: Smithsonian Institution Press.
Owl photo: By Mdf – Taken by Mdf, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=261200