Wildlife - Northern Spotted Owl: A Fight for Survival ~ Pawprints and Purrs

The Northern Spotted Owl (Strix occidentalis caurina) is dark to chestnut-brown with round or oval spots on its head, neck, back, and underparts. The flight feathers are dark brown and barred with light brown or white. Unlike most owls, the spotted owl has dark eyes.

Although this species is often referred to as a medium-sized owl, it ranks among the largest in North America. The average adult size is about 18 inches tall with a wing span of approximately 48 inches. It weighs between 17-29 ounces. The female is larger than the male.

Northern spotted owls are typically found in old growth forests of northern California and the Pacific Northwest of the United States and in southern parts of British Columbia, Canada.They may live as long as 10 years in the wild and up to 15-20 years in captivity.

As a result of declining habitat, there are fewer than 100 pairs of Northern spotted owls in British Columbia, Canada; 1,200 pairs in Oregon; 560 pairs in northern California; and 500 pairs in the state of Washington.

Suitable spotted owl habitat includes old-growth forest areas with multi-layered canopies of trees that are high and open enough for the owls to fly between and underneath them. Preferred areas have large trees with broken tops, deformed limbs and large cavities, capable of supporting the owls’ nesting materials.

Northern Spotted Owls enjoy a variety of prey, including flying squirrels, woodrats, mice and other small rodents. They also eat birds, insects and reptiles.

These owls are very territorial and intolerant of habitat disturbance. Even though they do not migrate, they may shift their ranges in response to seasonal changes. Each pair needs a large amount of land for hunting and nesting. They have a distinct flight pattern, involving a series of rapid wingbeats interspersed with gliding flight.

Pairs of males and females form in February or March and two or three white eggs are laid in March or April. The female incubates the eggs for 30 days. After hatching, it takes the young birds 34-36 days to fledge – or acquire the feathers necessary for flying. After the eggs hatch, the female sits with the offspring for 8-10 days. During this time, the male brings the female food. Each breeding pair uses about one to three square miles of forest more than 250 years old and below an elevation of about 4000 feet.

The biggest threat to the Northern spotted owl is loss of old growth forest habitat, as a result of logging and forest fragmentation. These threats are made even greater by natural disasters, such as fire, volcanic eruptions and wind storms. Timber harvest, fire, and clearing for agricultural and urban development have reduced spottted owl habitats to less than 10% of their original area, mostly since 1950.

Resources:
1. Defenders of Wildlife, Washington, DC USA
2. The Natural History of North America, Edward Ricciuti
3. U.S. Fish and Wildlife Service, Arlington, VA USA