On March 16, 2021, I visited my twenty nestboxes that are spaced 25 yards apart in a drainage ditch that borders the east side of Troy Road while a popular asphalt bike and hike trail also follows the ditch. Young deciduous trees stand close enough to the ditch to provide hunting perches for resident Eastern Bluebirds that enjoy the park for its manicured grassland that makes it easy for them to harvest ground loving insects crawling below. The park’s bluebirds also like to perch and hunt from fences that surround the park’s athletic fields.
The objective of my March 16 visit was to remove the six-inch-long pieces of felt weather stripping from above each nestbox’s front panel in order to welcome the first warm temperatures of spring. Before Memorial Day, or before the first forecast of ninety-degree temperatures, I open another vent above the back panel by loosening two screws to lower a plastic partition that allows cross-ventilation inside the box.
Fifteen more monitoring visits took place before I rewinterized the boxes on August 18, the earliest date to rewinterize on any of my nestbox trails, simply because late nesting House Wrens have never nested in Smith Park’s nestboxes. Winterized nestboxes help roosting birds cope with extreme winter temperatures, and cavity nesting birds seek available roost sites in cavities to cope with cold winter weather.
So, how did nesting birds do at Smith Park in 2021? The bluebirds had a most successful season after four of five nests (83.3%) fledged a total of 21 young. The one nest that failed had four eggs that disappeared sometime after April 14. There was no evidence to declare a guilty verdict, but House Sparrows would be the best guess.
Bluebirds laid 26 eggs, 21 (80.8%) hatched, and 21 (80.8%) fledged. Once hatched, 100% of the hatchlings grew to fly from their home sites.
The bluebird active season from its first egg to its last fledgling existed from April 11 to around July 17 for a duration of 97 days.
Tree Swallows occupied nestboxes with active nests with eggs and young for 83 days from April 29 through July 20. Ten Tree Swallow nests from 13 (76.9%) attempts produced 48 fledglings.
House Sparrows caused three swallow nest failures by attacking swallow nestlings. Sparrows also killed an adult female swallow sometime before April 24.
The swallows laid 70 eggs, 63 (90.0%) hatched, and 48 (68.6%) grew to fledge. Only 76.2% of hatchlings flew from their nestboxes which is concerning since anything below 90% for the hatchlings’ success rate is a sign of a problem. However, once the three sparrow-induced nest failures are removed from the data base, then the swallows fledged 48 of 50 hatchlings for a fledge rate of 96%, a very good job by the swallow parents.
A reduction of flying insects is very much in the news to explain reductions in our modern bird populations. Tree Swallows rely on flying insects and when they have to leave the visual vicinity around their nestbox in order to harvest insects, then their families become more vulnerable to destruction. You have to be able to see your home in order to protect it. During recent times, when I monitor and inspect nestboxes, I experience fewer dives from protective parent birds. They have to fly further from their nests to find adequate numbers of flying insects.
My job includes using VanErt Universal Sparrow Traps to capture, then humanely euthanize, alien House Sparrows at the park. From April 14 through July 23, I captured 46 adult sparrows and 13 have already been delivered to the Ohio Wildlife Center for a fastidious hawk that would only eat birds, and the remaining sparrows will go to museums at Ohio State and Ohio Wesleyan Universities for multiple educational uses. Sparrow remains are stored in plastic bags and kept in my freezer in an isolated container. All the sparrows were captured before their eggs hatched, so no nestlings had to be neutralized.
As always, in addition to enjoying raising and interacting with native birds, I enjoy the occasional conversations I have with folks that are enjoying the park. Smith Park’s hike and bike trail is fantastic and it hooks up with the city’s neighborhoods, so if you have never visited the park, give it a try. And, if you have a dog in your family, I know Fido will also enjoy the park.
Conserve on!