The nesting season on our bluebird trail is officially over. There has been no recent activity in any of our six nest boxes. Three species of bird utilized the nest boxes. The last nest, a house wren nest, fledged 1 bird during the second week of August.
House wrens were the most successful species with a total of 11 fledglings. Carolina chickadees fledged 9 birds this year. Bluebirds were way down at only 3 fledged.
This has been the the worst year, by far, for bluebirds. And, it was the first year house wrens successfully nested in our nest boxes. As mentioned, they fledged 11 young.
Birds Fledged Since 2012
2012 2013 2014 2015 2016 2017 Total
EABL 20 20 27 18 19 3 107
CACH 6 13 6 4 6 9 44
HOWR 0 0 0 0 0 11 11
Total 26 33 33 22 25 23 162
EABL=eastern bluebird CACH=Carolina chickadee HOWR=house wren
Our bluebird trail has averaged 27 birds a year.
Eastern bluebirds averaged about 17.8 fledged birds per year.
Carolina chickadees averaged about 7.3 per year.
House wrens averaged about 1.8 per year.
Looking at the table above you can see that bluebird numbers are way down this year, while house wrens have increased. I attribute the shift in numbers to habitat change and construction here at the Museum. Bluebirds prefer open habitat in which to nest. Two of the sites which had traditionally been used by bluebirds over the years have grown over from field or meadow into dense shrub. And, it was necessary to move two nest boxes due to construction projects here at the Museum. The only sites available for the move were edge sites with shrubbery up against woodland. House wrens prefer edge or shrub habitat in which to nest. Their breeding success reflects the habitat change and placement of the nest boxes.