On July 15, Dick Phillips and I set out on our tenth monitoring trip since March 24 to visit four of 18 American Kestrel nestboxes that hang from utility poles along a fifty-mile-long roadside project in Delaware County, Ohio. After checking the last box, we were able to proclaim that kestrels had laid eggs in 17 nests in 16 nestboxes, that only two nests had failed, that 68 falcons had fledged from 14 nests, and one nest remained active with two hatchlings, making for a prolific year.
The mid-July-monitoring trip included checking one box that contained a bluebird nest. It is normal for smaller birds with suicidal tendencies to nest in kestrel boxes after the birds of prey move on. When we find a Tree Swallow or Eastern Bluebird nest in a kestrel box, we use two deck screws to fasten a salvaged front panel from a retired bluebird box over the three-inch entrance hole, making a new 1-1/2 inch entrance that excludes hungry sparrow hawks. I had made the kestrel box safe for four bluebird eggs during a previous visit, so while two concerned bluebirds chattered at me from an electric wire above, I climbed my fiberglass ladder to inspect the eight-inch square chamber to see that their eggs had not hatched yet.
We visited two other kestrel boxes to clean them. For this task, one man stands on the road controlling the rope while the other climbs the ladder to snap a nylon strap around the pole and above the nestbox. The strap holds a steel carabiner that is a hinged, oval ring familiar to rock climbers. Our rope passes through the carabiner and has a small stick tied to its end. Each box lid is hinged to its front panel and a screen hook locks the roof in place. The person on the ladder unfastens the hook and raises the roof to thread the rope’s stick through the nest chamber and out the entrance. Tension is applied to the rope before the box is freed from the pole.
Each of our kestrel boxes hangs from a loop of ten-gauge wire that passes through the back of the box and around the utility pole. The wire loop rests over a roofing nail that sticks out from the pole on the side opposite the nest box. A latch connects the loop’s ends and unsnapping it frees the nestbox so it can fall to the ground as the person controlling the rope guarantees a gentle landing.
A spackling knife is used to scrape the walls of the nest chamber and to dig loose the caked waste cemented to its walls. The box is turned upside down to dislodge a thick layer of matted nest debris that is more than an inch thick. Fur pellets, insect wings, bird skeletons, frog bones, and other horrific remains are relics of family feasts, always accompanied by a unique stench laced with ammonia.
We always dump the box contents close to farm fields so soybeans and corn crops can recycle the falcons’ waste. We also stomp and pulverize the “kestrel nest cakes” and check for kestrel remains. Cainism, a nestling’s death by siblings, followed by cannibalism, has occurred during several nest histories in the past when food deliveries fell short, but all kestrels banded before July 15 this year have fledged. After cleaning, we pack each chamber with a three-inch layer of fresh white pine livestock bedding to ready the box for winter roosting and spring nesting.
The last nestbox checked on July 15 was most exciting. When we checked it 12 days earlier, we found a male kestrel, and I knew from his position and posture, that he was sitting on eggs in the filthy used nest. (Previously, a family of five had fledged from there before May 28.) The dutiful male did not move as I snapped his picture and gently closed the lid. (See photo to the left: males have slate-colored wings, female wings are brown.) On July 15, the chamber held two newly hatched kestrels, and if these hatchlings fledge, they will raise the 2009 total to 70. Most important, since the project started in 1993, this could be the first kestrel nest box to raise two broods in one season. Twice before, second clutches of eggs were laid, but they failed to hatch. We will return to this box during the first week in August, and if we find healthy nestlings, we will fit them with leg bands.
Why band kestrels? Aluminum leg bands supplied by the U.S. Fish and Wildlife Service have been attached to all of 561 kestrels that have fledged from the project’s boxes since 1995. Band recoveries from eight dead birds have provided valuable information. All eight died during their first year of life. Of these, three birds met their fate as “road-kills” shortly after fledging. Four other birds were found dead after dispersals of 25 – 95 miles, near the Ohio communities of Canton, Danville, Johnstown, and North Lewisburg. The longest fatal dispersal was 380 miles to Toccoa, Georgia. These band recoveries tell us that Delaware County is doing its part to conserve our smallest falcon whose populations have been decreasing throughout its range. But before conservation is truly successful, young birds dispersing from their natal sites must find suitable nesting and roosting sites for their own survival and future families. In other words, before there are more kestrels, there must be more conservationists that erect nestboxes throughout their range.
Falco spaverius responds well to our efforts to help it, making for a fun-filled hobby with many rewards for its helpers. For example, whenever I see an American Kestrel perched on a wire, I can’t help but smile. And that’s priceless.
Raptor on!