We began about 10 years ago with nest box for northern flickers. These common, primary cavity nesters are facing many problems from loss of nesting habitat to pressures from invasive species (see here). In order to address the first issue we set up a nest box. This was very successful and effective, and based on how quickly they found the box and occupied it, it is obvious they are looking for, and are limited by, places to nest.
In front of my neighbor's house are decadent silver maples (see above), that you'd think would offer great nesting habitat for flickers, and they do, but unfortunately the cavities get occupied by squirrels instead, and have been for the 10 years we've lived beside them.
But it appears that this year the flickers will finally be nesting in one of these decadent trees and I couldn't be happier.They did excavate our nest box (see photo at the top of the post), and I thought they were going to nest in it. But at the same time, they also excavated a cavity about 30' up one of the silver maples (photo above, arrow acknowledgement: Bike Garden), perhaps our nest box was a back-up for what inevitably happened when flickers tried to nest in the maples- squirrels would occupy the cavity. But maybe not this year.
Unfortunately wildlife gardening in an urban- or sub-urban setting is not just about planting the right plants and putting up nest boxes, unfortunately it is really about introduced pest management. The primary exotic pests here are starlings, house sparrow and squirrels. Controlling pests is not the most glamorous part of having a wildlife garden, but it is perhaps the most important.
In order to combat these invasive species, we have done several things- making the garden less hospitable for them is the first step , but then there is also control, or killing (click here for more information). As far as making the garden less hospitable, that starts with feeders and nest boxes (click here for information about lessening bird feeders), and native plant landscaping (see virtually any post on my blog for this thought!). Both feeders and nest boxes need to be designed for native birds, so no perches, only food they eat, and really very few feeders, and only seasonal ones (click here and here for more information).
Since we stopped feeding with sunflower seeds, we have seen the number of pests decline dramatically in the garden - including US native, but not Montana native, house finches, which essentially disappeared from the yard. In the summer, spring and fall, there is so much natural food, much of which we have planted, feeding is not important and mainly attracts unwanted, or invasive birds and animals, and it also causes unnatural high congregations of birds, that make them susceptible to other pests, like cats (click here for my thoughts on this).
Secondly we only use nest boxes that are appropriate for native species that we are likely to attract, not bluebird boxes for example (read more here).
Third there is control or killing squirrels. In our garden we have a trap set up, and any squirrel I trap, I kill. This started several years ago, and I went from over 200 squirrels/ year down to fewer than 20 last year and this year will be even fewer. As a result, we have seen birds use the garden much more often and differently than when squirrels patrolled the grounds. And most importantly, birds like northern flickers might just nest in natural places now. Like I said, this is the first year that I am thrilled the flickers will not nest in our garden- perhaps the greatest accomplishment in our wildlife garden so far.