Facilitating the protection and restoration of endangered species and ecological communities on BC’s South Coast

Endangered Times – Fall/Winter 2017-18: Species Pick!

Introducing the Western Screech Owl kennicotii ssp. Length 19-25.5 cm, Weight 120-305 g.

Megascops kennicotti kennicotti is a member of the family Strigidae (“typical owls”), western forms were long thought to be one in the same species (conspecific) as Eastern Screech Owl (M. asio). It was not until the late 1960’s that Western Screech Owl was designated as a separate species. The coastal subspecies is distributed throughout the Coast Region including Vancouver Island and the Gulf Islands (absent from Haida Gwaii). This subspecies was once considered to be one of the most common small owls in southwest BC but has shown a strong decline since the 1990’s, especially near settlement areas in the Fraser Lowlands and southern Vancouver Island.

 

 

A small owl with yellow eyes and a small beak, black eyebrow ridges lead up in a “Y” configuration and short ear tufts on the corners of the head. The head is crowned with a triangular russet and black cap that follows the eyebrow ridge to the ear tufts, which are not always raised away from the other head feathers. A master of arboreal camouflage, the white to pale-grey plumage is streaked with black and brown making it difficult to see against tree trunks or cavities where it generally roosts and nests. The coastal subspecies tends to have greater brown colouration while the interior subspecies is greyer. As with most raptors, females are generally larger and heavier than males. Northern subspecies are often larger and heavier than the southern subspecies.

 

Similar Species: There are a number of arboreal owl species, some like the Long-eared and Great-horned Owl have ear tufts and similar camouflage patterning to the Western Screech Owl. While these species are superficially similar, they are significantly larger than the diminutive Western Screech Owl.

Western Screech Owl is a secondary cavity nester, dependent on other species such as Pileated Woodpecker and Northern Flicker to excavate nesting cavities. This owl will also readily use nest boxes. Breeding territories are closely associated with riparian or low-mid elevation forest habitats and must contain at least two suitable cavities which are used for both nesting and roosting. Where optimal habitat occurs, home range sizes can be very small, and are generally assessed at 2.5-10 ha. Young of the year disperse from the natal area, with females travelling about three times as far as males (about 15 km vs. 5 km) in the first 3 months of dispersal. In British Columbia, nests ranged from 1.2 to 12.2 m above ground; all nests reported were in trees >25 cm in diameter base height. Day roosts are usually in deciduous trees with a mean height of 21.2 m, at an average of 4.6 m high. The tree density around roosts tends to be greater than in the surrounding forest.

Threats: The greatest factor believed to be contributing to the Western Screech Owl’s recent decline 0ver the last two decades is the expansion of urban adaptor species like the Barred Owl and Great-horned Owl which can out-compete the smaller screech owl for food resources and nesting cavities. These larger owls also directly prey on the adults and chicks of smaller owl species. Add to this the loss of preferred nesting features and prey availability due to disturbance from urban and rural development and logging and competition for nesting cavities with other introduced species such as Eastern Grey Squirrel and European Starling.

For further information see the SCCP’s profile page for Western Screech Owl, kennicotii ssp. or the SARA Registry recovery page.

image credits: Adult WESO (kennicotii ssp. from Cheam Lake) Gord Gadsden used with permission, Adult WESO (macfarleini ssp.) USFWS used under creative commons license, WESO Owlet (ssp. unknown from the Pacific Northwest) "Camera Trap Codger" used under creative commons license

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