Bluebird box on fence, Kawartha Lakes, Ontario
Driving along the back roads of Kawartha Lakes (and many other rural areas in Ontario) it's fairly common to see bluebird boxes hanging on fences next to farmers' fields.
Until a few years ago, bluebirds were in serious decline due to the use of pesticides and loss of habitat, in part caused by English sparrows and starlings that vie for the same cavities bluebirds like for raising families. The bluebird population in Southern and Central Ontario is now stable, and bluebird boxes in rural areas is cited as a major reason.
I am linking to Friday Fences here.