Once the nest boxes are all cleaned and the data all entered, it is fascinating to take a moment to really look at how the season went. We try all kinds of methods to improve our nest box trails for local species and speculate on how things are going but until we can look at the data as a whole we don’t know. This year was a great example.
There is more detail in the Summary Report attached but I will give a brief synopsis. I will start with what we did know before data compilation. We had three of the Western Bluebirds from last year’s translocation return to Vancouver Island, two of them established territories in Cowichan Valley. Two new pairs were translocated from a healthy population in Washington. A total of 12 fledglings were raised over the season. What wasn’t clear until we looked at the numbers was that native species using the boxes doubled their number of successful nests this year! And there were half as many attempts by House Sparrows to take over boxes. No matter how many bluebirds we bring over, they will only be successful if their nesting habitat is safe so I find this news especially encouraging.
On the less encouraging side, an Avian Flu swept across North America this year, dashing our plans to bring more families of Western Bluebirds over for this season. It is lucky that the two pairs that did establish territories were so successful. There wasn’t a single mortality this season! We will continue to bring bluebirds over next year so that we can reach population numbers that are more resilient to the winds of chance.
Give a moment to look over the Summary Report if you are curious. It is time to wish our bluebirds safe travels and hope the winter treats them well.
Cowichan Bring Back The Bluebirds Project 