The Flying Shingle
Just for the Birds
Welcome back Western Bluebirds!
by Sharon McInnes
Monday, September 3, 2012
Click for larger photo
Western Bluebird ~ Photo by Dave Menke, courtesy of USF and W

It’s been over seventeen years since a Western Bluebird (Sialia mexicana) was documented nesting on Vancouver Island or the Gulf Islands. In BC today, the bluebird is considered Red-listed and Extirpated. But this year the Bring Back the Bluebirds team at The Nature Conservancy of Canada (NCC) and The Garry Oak Ecosystems Recovery Team (GOERT) partnered to try and bring this lovely migratory bird back to the Salish Sea.
Western Bluebirds are smaller than a robin, but stocky, and have a thin, straight bill and fairly short tail. You can recognise males by their shiny blue head, back, and throat. Some males have a rusty-red shoulder patch. Females are mostly a gray-buff colour with a pale orange breast, eye ring, and whitish lower belly.
Scientists suspect that the loss of Western Bluebirds is due to habitat loss (as usual) and competition for nesting sites with European starlings and House Sparrows, which are both introduced species. The goal of Bring Back the Bluebirds is to re-establish a population of up to ninety Western Bluebirds in BC over the next five years.
This year the first two pairs of bluebirds were released on May 8 and 10 at the Cowichan Garry Oak Preserve – which was purchased by the Nature Conservancy of Canada 11 years ago – at Maple Bay near Duncan. According to Carolyn Masson, of GOERT, the bluebirds came from “a healthy population at Fort Lewis-McChord Military Reserve in Washington State”. (Cowichan News Leader, May 4). Then, in June, two pairs of parents with their nestlings were translocated to the Cowichan Valley. One pair was released on June 11.  And at the end of July, four Western Bluebird eggs hatched! Scientists are hopeful that this year’s successful offspring will return to the area to nest next year.
Each bird is banded with a unique colour combination of four bands, with two on each leg. Three are coloured plastic; one is an aluminium band from the North American Bird Banding Program. Since each bird wears its own specific colour combination, scientists can track its movements, survival, and breeding success.
Western bluebirds inhabit open coniferous and deciduous woodland as well as back yards, burned areas, and farmland. They nest in natural cavities in trees but because their bills are not equipped to dig holes, they are secondary-cavity nesters, using the abandoned nest sites of woodpeckers. (A good reason to let dead trees stand – as long they’re not in danger of falling.) Bluebirds will also nest in man-made boxes. The holes in the ones recommended by GOERT have a very specific size that keeps European starlings (although not house sparrows) out. (For information about hosting a nest box, go to www.goert.ca/publications_resources/bluebird.php.)
During the breeding season Western Bluebird pairs hunt for and choose nest sites together. They typically raise their family as a couple, but sometimes engage in cooperative breeding. In these cases, most male offspring and a few female offspring remain with their parents, who are joined by immigrant females.  The cooperative “kin neighbourhood” usually remains together throughout the winter. They share berries, sleep together on cold nights (up to thirteen bluebirds have been known to share a single nest box), and jointly defend their territory against intruders.
Outside the breeding season, these thrushes form flocks of up to about 100, sometimes mixing in with Mountain Bluebirds, American Robins, and Yellow-rumped Warblers.
In summer, Western Bluebirds sit on low perches and swoop lightly to the ground to catch grasshoppers, caterpillars, beetles, ants, wasps, and pillbugs, as well as spiders and snails. In winter they eat elderberry, grapes, mistletoe, raspberries and blackberries, serviceberry, sumac, chokecherries, juniper, and poison oak, and supplement their diet with insects.
GOERT is calling on all Gulf Islanders to help them find the released banded birds and their babies. (Follow the bluebird news on FaceBook under Garry Oak Eco.) Although I haven’t seen one, it’s possible that Western Bluebirds are on Gabriola right now! If you should see one, please record the location and, if possible, note the colours on their bands. Then email GOERT at bluebird@goert.ca, or call 250-383-3427. Then let me know! I’d love to come and take a photo.

Sharon is the author of “Up Close & Personal: Confessions of a Backyard Birder” and of The Gabriola Bird Blog (http://gabriolabirdblog.blogspot.com).

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