Survival in an urbanized landscape: radio-tracking fledgling eastern bluebirds on golf courses
My thesis project looked at how fledgling bluebirds adapt and survive in an urbanized landscape, specifically looking at golf courses and reference parks in the Williamsburg area. I used radio-telemetry to track 156 fledglings over the summers of 2008 and 2009, and estimated mortality of these babies to be close to 35% in the first 40 days postfledging. The fledglings died to a variety of causes, including hawk predation, snake predation, window strikes and starvation/disease. Though there was no difference in survival between birds living on golf and reference sites, I did find that fledglings had greater survival later in the season, which is opposite of what most people think. Additionally, I found that early (before 10 days postfledging) survival was related to the amount of forest cover around the nest box, with increased forest cover increasing survival. Though bluebirds benefit greatly from the addition of artificial nest boxes, this study indicates that we must consider the placement of boxes to ensure fledgling survival.