Don’t screech quietly into the night
If you’re lucky, you might get to hear the hoot of a Western screech owl…a series of hoots that trails off towards the end. It’s ironic that this feature of its call may also describe its future. The western screech owl is a small owl, 18-25 cm long, about the size of a crow.
No snowbirds these, screech owls stay in B.C. through the entire winter. They are secondary nesters, taking over the homes of woodpeckers or other natural cavities in trees. Areas immediately next to rivers or wetlands are a necessary component of the owls’ home ranges, with owls always nesting within 200 metres of the water. This restricts the owl to very particular habitats. The screech owl is relatively uncommon locally, primarily being distributed on the coast and in the southern Okanagan.
Researchers have estimated approximately 200 breeding owl pairs in the Okanagan Valley. The current owl population is pressured by habitat loss and interactions with other owls.The BC Ministry of the Environment considers the Okanagan screech owl to be red listed, a species that is endangered and at risk of being lost. As well, the species is listed as endangered on the federal lists. In an effort to conserve the western screech owl, managers are focusing on minimizing habitat loss and on getting accurate population estimates.The loss of habitat is likely having the biggest effect on Western Screech owl numbers.
The owl prefers valley bottom habitats and riparian areas; however, these are also the area most prized by urban developers. In addition to losing the battle with developers, flooding caused by hydroelectric development and deforestation are taking more prime habitat out of the mix. For example, in the Okanagan, dam development has destroyed 87 per cent of water birch and 32 per cent of black cottonwood habitats in the last century.
Both habitats are vital roosting grounds for the screech owl.A number of measures are available to help protect this endangered species. Knowing how many individuals there are and where they are is critical in the management of any endangered species.
You can help researchers by participating in the annual B.C. Nocturnal Owl Survey (www.bsc-eoc.org) by searching local areas for any signs of the screech owl. In addition, building a screech-owl nest box is a great way to provide more suitable habitat. Finally, more practical city planning will reduce the threat to the owl from urban sprawl.
This would encourage higher densities living without further expansion of city boundaries, at times expanding into owl habitatThe screech owl is also threatened by changing ecological dynamics, not really something we can or want to change but of which managers need to be aware.
The additional threat comes from the natural introduction of barred owls in the area through the range expansion of that species. In the last 30 years, barred owls have become established in the southern Okanagan, and now anecdotal reports suggest they are regularly predating on the smaller screech owls. If barred owls continue to progress into screech owl territory, more pressure will be put on already-stressed screech owl populations.Western screech owls are threatened by multiple forces especially in the southern Okanagan.
Degradation of habitat and encroachment from other species has pushed this owl to the brink. Proper management of human development and the preservation of habitat for these creatures will help to keep the Western screech owl and its call from trailing off into the sunset.