By Nature Vancouver and Delta Naturalists
Report submitted by Peter Ward
Barn Owls are listed under the category Federal Species at Riskin Canada, and are subject to a Provincial Recovery Plan. The population in BC is confined to the Lower Mainland and Fraser Valley, and to the south coast agricultural regions of Vancouver Island. The main habitat requirement is pasture land, and the favourite food source is Townsend’s Vole.
Since 2011, members of Nature Vancouver (Peter Ward, Ken Hall and John Toochin) have been involved as volunteers in the construction of Barn Owl boxes for the Vancouver, Delta and Fraser Valley areas. In 2016 members of Delta Nats (DNS), including Jim Kneesch, Chris McVittie, Jack MacDonald and Mike Bayliss joined the group. Sofi Hindmarsh provided inspiration for the project, acted as anchor in getting funding for materials and did field installation of boxes. We also worked directly with Iona Beach and Boundary Bay Regional Parks, with several golf courses, and with UBC Farm. DNS (under Tom Bearss) and Nature Vancouver have both provided funding for small numbers of boxes. A recent substantial grant was provided to us by BC Nature, via DNS.
To date we have produced about 100 boxes, in various designs. The (British) Barn Owl Trust pole box layout provided inspiration for some boxes, and we have since adopted our own standard design, branded Cascade, made from Baltic Birch plywood. Some of these are deployed in barns, and others (with a large deck around the box for owlets to exercise), are pole mounted on 6 x 6 cedar or hemlock wood, about 3.5 to 4 m above the ground. Prior to construction, we request support for the materials, and do the woodwork as volunteers. Usually the sponsor/land owner helps erect the boxes. We look for habitat such as substantial areas of roughed grass, and also blueberry fields, good for the presence of Townsend’s vole, for positioning our pole boxes.
Prior to nesting, the owl pair regurgitates pellets on the floor of a new box, providing a warm “carpet” for egg laying and rearing young. We check a few times in the spring and summer breeding season, using an IBWO remote camera probe, to see whether boxes are occupied, and whether owlets are reared to full fledging size. These surveys are done just before dusk. 3 to 5 eggs are laid in mid March to early May, and young owlets in our boxes fledge typically during mid June to early August.
Our Cascade group has also been building and deploying swallow and chickadee boxes in BC for more than a decade. Please contact Peter Ward for more information.