Follow the bouncing ball! That is what the “boop, boop, boop” call of the Western Screech-owl brings to mind! This largest of our trio of little ‘arboreal’ owls on the South Coast is in trouble.
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 (O. asio). It was not until the late 1960’s that Western Screech-owl was designated as a separate species. Like the Northern Saw-whet and Northern Pygmy Owl they share forested and riparian habitats with, ‘WESOs’ have yellow eyes and are 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. The one distinguishing feature that sets them aside from Saw-whets and Pygmies is the set of small ear tufts that can be found at the end of black eyebrow ridges that lead up in a “Y” configuration from the facial disc.
Two subspecies occur in BC, the interior macfarlanie and our coastal kennicotti. The coastal subspecies ranges west of the Cascades up to the North Coast including coastal islands, Vancouver Island and Haida Gwaii. Right around Pemberton and into the interior both subspecies overlap with the macfarlanei subspecies dominating throughout southern BC to the Alberta border.
Both subspecies were relatively common in BC until the mid-2000’s but have recently displayed dramatic declines. The coastal subspecies was listed as Special Concern but has recently been proposed for up-listing to Threatened while the interior subspecies is listed as Endangered under the Federal Species at Risk Act. Their vulnerability to human activities, particularly urban and agricultural development and forestry practices in low elevation, mixed coniferous-deciduous forests - which provide prime habitat for this fascinating bird, have been considered major threats. In addition to habitat loss, Western Screech-owls may also be threatened by Barred Owls, a naturalized and more common relative of the Northern Spotted Owl. As Barred Owls have expanded their range, they displace other endemic owl species from historic habitats, compete for nesting cavities (the primary nesting feature used by screech-owls) and are also know to prey on adult owls and nestlings. Barred Owls also more easily adapt to urbanized landscapes and tolerate a wider range of disturbance than other arboreal owl species.
Locally the South Coast regional office of the Ministry of Forest Lands and Natural Resource Operations is working to develop a protocol for Western Screech Owl nest box placement and monitoring.
Western Screech 'Owlet' (kennicotti ssp.) courtesy of Camera Trap Codger
Western Screech Owl adult (kennicotti ssp.) from Pemberton courtesy Greg Ferguson