Background
During years past, as I have avoided Route 23 traffic to travel to Delaware State Park to monitor my nestboxes there, I have frequently traveled past Smith Park, located along Troy Road on the west side of Delaware, Ohio. Smith Park’s drainage ditch runs along Troy Road and creates a natural boundary that protects leash-free dogs and children from bolting onto a well-traveled country road. The ditch is rather deep and supports natural vegetation, including cattails in much of its 400-yard run. The ditch curves from its north-south course to flow east into a pond.
I’ve always thought that the ditch would be a good location for a line of nestboxes spaced at twenty-five yards apart with Tree Swallows being the primary target species. (Eastern Bluebirds can claim only a few boxes due to their requirement for larger territories.) I also thought that installing nestboxes close to Troy Road would be an experiment in more ways than one. Would nesting birds respect the danger of the road’s traffic, and could the boxes stand all year and survive possible blasts from routine snow plowing during winter months? Well, thanks to permission granted by the City of Delaware, the experiment has been launched, and so far, the results are positive. I submit my report to share the good news.
Installation
After talking with Delaware City’s Stacey Davenport, I installed six boxes on March 23, 2016, followed by two more boxes on May 19. Before any more boxes are installed north along the ditch, the Ohio Utilities Protection Service (OUPS) will be consulted in order to safely miss underground utilities. I use steel fence posts, called “T-posts,” to support my nestboxes and PVC baffles. The posts are driven into the ground 1-1/2 feet and stand five feet above ground on the far side of the ditch. One or two steel hose clamps hold a pipe extension to each post to hold its nestbox six feet above the ground. A conduit clamp on the pipe extension supports a 33-inch-long section of four-inch drain pipe that is painted glossy green, all to protect nesting birds from climbing raccoons, snakes and other hungry critters.
Results
Tree Swallows attempted four nests with eggs and three of these nests were successful. Twenty-two eggs were laid, 15 (68.2%) hatched, and 14 (63.6%) grew to fledge. Once hatched, 93.3% of hatchlings fledged after an average of 21 days of growth. One nest of six swallow eggs was taken over by alien House Sparrows.
If we want to judge the worth of Tree Swallows, based on scientific studies, each family consumes more than 300,000 flying insects during the 45-day period that they use a nestbox for nesting. The flying insects in their diet are extremely small varieties with 99-percent being smaller than ten millimeters which is one-half the width of a nickel. The insects in a Tree Swallow’s diet include mosquitoes, deer flies, leaf hoppers and midges. As swallows glide and dine above the athletic fields at the park, they are protecting park participants and visitors from irritating insect bites and possible diseases spread by mosquitoes. Since I played center field during my teenage years, I know how irritating deer flies and mosquitoes can be while you are trying to concentrate on each pitched ball.
Eastern Bluebirds attempted one nest with four eggs and all four hatched to fledge for a 100% rate in all categories. May 26 was their first-egg-date and I used the family to educate eight talented and gifted middle school campers that were enrolled in the second week OWjL Camp at Ohio Wesleyan University. Each year, as I have since 1989, I teach “Bluebird Trail Management” during the first period of all three weekly sessions prior to July 4 week. On Tuesdays, Wednesdays and Thursdays, we visit my bluebird nestboxes at Delaware State Park where we examine nests with eggs, young nestlings, older nestlings and other nest happenings of House Wrens, Tree Swallows and Eastern Bluebirds. Each camper gets to attach a U.S. Fish and Wildlife Service leg band to a nestling under my intense guidance. On June 22, four members of my OWjL class banded 11-day-old bluebirds at Smith Park since there were no bluebirds at the state park between eight and 12 days of age for proper banding. After Smith Park, we continued to Delaware State Park to complete the day’s class.
Part of responsible bluebird trail management is controlling an alien species from Europe, the House Sparrow. House Sparrows claim boxes by inflicting hideous head wounds on our native species, then they cover the decaying remains with their nests. Smith Park was infested with sparrows for several reasons. The park is four-tenths of a mile from suburbia when there are bird feeders. There are barns nearby, and most important, during summer months, an endless supply of food is delivered daily to the park by park visitors. Nobody is feeding the birds by hand, but automobiles deliver huge amounts of recently impaled insects in their grills.
I trapped and humanely dispatched 22 adult House Sparrows and aborted 29 eggs from seven of the eight boxes. Had I not removed sparrows, swallows and bluebirds would not have nested! I do not kill nestlings, for multiple reasons, but for the first time in more than fifty years, I allowed a family of four sparrows to fledge around July 4.
Normally, I save and freeze dispatched sparrows and present them to the Ohio Wildlife Center so they can be fed to recuperating hawks. In 2016, OWC did not accept sparrows as they were following government directives in an effort to avoid the spread of avian flu. The ban has since been lifted.
I am aware of horrified reactions of some citizens when they hear of bluebird trail managers controlling sparrows, so I have been careful to hide my anti-sparrow management practices.
As winter approaches, four of eight boxes stand close to Troy Road and might be subject to snow thrown by snow plows. If the winter proves to threaten the physical well-being of the boxes, then I will practice storing boxes and their baffles at my home. After all, I remove and store 57 boxes each year from the Delaware Wildlife Area before the hunting seasons begin. I return boxes by March 15 each spring. So, I foresee no problems.
Last August, I “winterized” all eight boxes by closing their back vents and plugging their front vents with strips of felt weather stripping. Tree Swallows have migrated to warmer climates but some bluebirds stay the winter here in Ohio. So, for bluebirds wanting to stay, they have eight cozy, vent-free boxes to roost in.
I look forward to adding ten or more boxes to the Smith Park ditch, but first, I must fully recover from rotator cuff surgery on my shoulder. Humpty Dumpty needs time to heal.
Conserve on for biodiversity.