Natural History
CHARACTERISTICS
As a medium-sized owl, the northern spotted owl stands tall at about 40 cm with a wingspan of one metre. Females are larger than males and weigh around 700 grams, while males weigh around 600 grams.
They have rich, dark or chocolate brown feathers, with white spots on the back of their heads and necks that give them their "spotted” name. Their breast is white with brown horizontal markings, their eyes are a deep brown, and their beak and feet are a subtle shade of grey and yellow.
HABITAT
The northern spotted owl's existence is intricately tied to Pacific Northwest coastal old-growth forests, which are far more than just "old trees." These unique ecosystems are predominantly made up of Douglas fir or western red cedar trees that are between 100 and 300 years old in Canada, towering at 19 metres in height.
These forests have a multi-storied canopy, where sunlight filters through in patterns that match the rich colours and markings of spotted owls. There is large coarse woody debris all around and many snags with broken tops. Here the spotted owls find refuge, nesting in the cavities at the top of snags.
RANGE
There are three subspecies of the spotted owl, and the northern spotted owl occupies the northernmost portion of their range. It stretches from the Pemberton-Lillooet area down into northern California on the west side of the Cascade Mountains.
These owls hold an important role as an "umbrella" species— their protection signifies the preservation of an entire ecosystem. The health of the forest is also intrinsically tied to the presence of spotted owls.
A pair of spotted owls need an expansive 30 square kilometres of continuous forest, equivalent to seven times the size of Stanley Park.
LIFE HISTORY
Northern spotted owls typically live about 10 years in the wild and up to 25 years in captivity. They are monogamous and mate for life once a bond is formed. Males can start breeding as early as one year old, while females are generally slower to mature and start reproducing as young as one year and as old as seven years.
In the wild, breeding season happens once per year in the early spring, with 1-3 eggs being laid around April. Working together as a family, the female sits on the eggs and cares for the young, while the male provides food for them.
DIET
In the wild spotted owls eat mainly northern flying squirrels, followed by bushy-tailed woodrats, and other small mammals. They do not regularly eat insects, birds, reptiles, or amphibians, although it is possible.
The success and sustenance of spotted owls is intricately linked to living in productive ecosystems that can support abundant rodent populations.
THREATS
The northern spotted owl has become endangered for three main reasons:
1
Habitat Loss
Over the past 100 years, the amount of old-growth forest habitat available for the northern spotted owl has decreased significantly. There is approximately 300,000 hectares of suitable habitat currently protected by the Government of B.C. for future releases of spotted owls.
2
Habitat Fragmentation
The remaining habitat for the spotted owl has been severely fragmented (broken up), which creates a barrier for dispersing young who need continuous forest. Focusing on ways to connect patches of old-growth forests within their natural range, and across borders, is key for their recovery.
3
Invasion of the barred owl
The barred owl is originally from eastern North America and has quickly spread west due to human development. Although similar to the spotted owl, the barred owl is more aggressive and adaptable, outcompeting the spotted owl and disrupting the balance of old-growth ecosystems.
POPULATION AND CONSERVATION
There are currently less than six wild northern spotted owls remaining in Canada. They are provincially Red-Listed and federally recognized as critically endangered. There are greater numbers in Washington and Oregon, but spotted owl populations are decreasing. The spotted owl across all three subspecies (California, Mexican, and Northern) is internationally recognized as threatened.
The NSOBP is the only place in the world breeding the northern spotted owl with the hope of establishing a self-sustaining population in the wild.
