During the Spring and Summer of 2020, 19 Eastern Bluebirds and 36 Tree Swallows fledged from nestboxes that stand 25 yards apart for a distance of a quarter mile in Smith Park’s drainage ditch along Troy Road in Delaware, Ohio. This simple conclusion has a bigger story with many chapters to tell, so read on to learn of many adventures that result when nestboxes are blended among cattails and other wetland vegetation.
Data reveals that there were at least four pairs of bluebirds that attempted seven nests with eggs, and only one nest failed after House Sparrows destroyed five eggs to claim the nestbox. So, of the original 31 eggs laid, 24 (77.4%) hatched, and 19 (61.3%) fledged. Once eggs hatched, 79.2% grew to fly toward an adult world.
From the first bluebird egg laid on April 1 until the latest fledging event on August 9, 131 days made the active nest season for the park’s bluebirds.
Tree Swallows started 13 nests with eggs, but only nine (69.2%) nests successfully raised fledglings. Of the four nest failures, only one nest failure was caused by House Sparrows. Causes for the other three nest failures were not determined due to a lack of evidence, but flying insect populations were low, and had been further lowered by intensive rain events, all to negatively affect populations of aerial feeding birds.
Swallows laid 58 eggs and 41 (70.7%) hatched, 36 (62.1%) fledged, and once hatched, 87.8% of hatchlings grew to fledge. The earliest Tree Swallow egg was laid on May 7, and the last fledgling flew around July 23 to make a 78-day season of active nests.
House Sparrows, the alien species that was shipped from England and released in New York City in 1851, invaded 16 of the 20 nestboxes in Smith Park. They killed three adult Tree Swallows and wiped out five bluebird eggs in one nest. I used Van Ert Universal Sparrow Traps to remove 49 adult sparrows between April 1 and July 11.
After the murderous threats are humanely neutralized, I place them in plastic sandwich bags and they are transferred to my freezer once I arrive home. During most years, I present them to zoology museums at Ohio Wesleyan and Ohio State Universities where they are used to train student curators on how to prepare study skins so they will ultimately be able to prepare a native bird’s beautiful skin without damaging it.
Some sparrow specimens are used in lab sessions to teach about parasites and bird morphology. Female sparrows that have one or two eggs in their nests will also have immature eggs forming in their bodies that are good to teach life cycles and egg development once they are dissected.
I also give sparrows to the Ohio Wildlife Center where they are fed to owls and hawks on the mend. On September 29, I delivered 24 frozen sparrows to the wildlife center to help a recovering Cooper’s Hawk that preferred to dine on birds. None go to waste. In fact, on extremely hot days when I am too busy to deliver remains to my home before decomposition begins, I return deceased sparrows to the environment so a scavenger can enjoy a feast, or flies can produce offspring to feed my swallows.
Once again, not one stick appeared in any of the boxes to prove that House Wrens are not part of the park’s habitat. Brushy habitats occur at my other nestbox projects and wrens raised 689 offspring this year. Other birds absent at Smith Park are chickadees and titmice that need forest habitats.
I started monitoring Smith Park on March 9 this year, since it was time to remove weather stripping from the front vent above the front panel to de-winterize the box before the nesting season. I always open the second vent above the back panel before Memorial Day, or before the first forecast of ninety degree temperatures. Two small screws hold a plastic partition over the back vent during the winter months.
A total of 18 days of monitoring and checking sparrow traps were required to wildlife manage the park’s boxes for the 2020 season. On my last visit on August 6, I winterized all the boxes by plugging the front vents and covering the back vents. My season at the park lasted 161 days for 44.1% of the year.
My swallows continue to control the mosquitos and other nuisance insects so I never have to apply insect repellant. I enjoy the occasional interactions with park visitors as they ask questions or add their own observation accounts. Yes, many people are enjoying Smith Park’s avian resources.
The park has a nice asphalt bike and hiking trail that parallels Troy Road along with adequate parking lots within its boundaries. So, be sure to visit Smith Park in the future, and enjoy its feathered residents.