Today's journal entry is intended to give you a glimpse into the issues faced by our Richmond falcons and the biologists from VDGIF and the Center for Conservation Biology at The College of William and Mary as we attempt to maximize the chicks' chances of survival.
Many years of observing chicks fledging from nests on bridges and tall buildings in Richmond and other cites have revealed that the eyases are prone to jumping off the ledge or bridge before they can fly well. To make matters worse, these young birds tend to "follow the leader;" if one jumps, the others are likely to soon follow. In the wild, on a cliff perhaps thousands of feet above the ground, the fledglings have a good chance of catching a natural thermal; but, even if they fail on the first attempt, they usually can land on a cliff perch or tree, still far above the ground, and try again when fully rested. In contrast, a young bird taking its first flight off of a bridge or ledge only 100-300 feet above the ground must successfully fly and catch a "thermal" to soar back to a suitable perch: if it fails, it will end up on the ground or in the water and probably perish.
Following 3 years of our releasing young falcons in downtown Richmond from 2000 through 2002, a pair of falcons nested in Richmond for the first time in 2003. The pair established a nest on the 17th floor ledge of the First National Bank "BB&T" building. Although all seemed to be going well, the eyases jumped off the ledge a day or two before they were flight-ready, and we spent several frantic days trying to rescue grounded fledglings from the middle of downtown sidewalks and highways; a real mess that resulted in a couple of serious bird injuries from collisions with the ground or buildings.
Thus, in 2004 we decided to transfer the chicks to a pen on the roof of the building, about 30 feet directly above the nest box. This allowed us to "hold" the chicks until we were confident they were strong enough to fly. The "Falcon Pen" essentially is an extra-large dog pen, mated to a smaller pen that served as a replacement "nest box" (see photo). The smaller pen was covered with ventilated pegboard to provide shelter from sun and rain. We were counting on the adults feeding their chicks through the wires of the pen. Sure enough, though it took a few hours for the adults to figure things out, they eventually located their chicks and began feeding them. To give them the benefit of a few extra days to "pump up" in preparation for their first flight, we waited until the chicks were about 50 days old before releasing them. Though we opened the pen door and left the roof as quickly and quietly as possible, the adults became very agitated at our intrusion. This got the chicks excited as well, and both chicks bolted from the pen as soon as the door was opened, before we could get off the roof. One flew safely, but the other promptly flew into the side of a building and died.
So..., in 2005 we decided to "remotely" open the Falcon Pen door, to see if this would keep the chicks and adults calm during the release. Using some "MacGyver" ingenuity, we devised a low tech "trigger" device consisting of bungee cords, a 5-lb weight, and a plastic bottle of ice attached to the Falcon Pen door (see photo). When the ice melts it releases the weight (hung from a string frozen in the bottle of ice) that keeps the door closed, and allows the bungee cords to slowly open the pen door. This process occurs over the course of 2-4 hours, and allows us to observe the chicks from distant rooftops. We have used this trigger for 2 years now, with great success. Though the adults become aggressive when we attach the device, they quickly calm down after we leave. The releases have gone very smoothly, with all the chicks calmly leaving the Pen, surveying their surroundings for a few minutes or hours, and then taking successful first flights.
Since 2006 the falcons have nested at Riverfront Plaza. There we have adapted the Pen to fit directly onto the front of the existing nest box, as you can see on the live Web images. Today we banded the chicks and will transport two of them to Breaks Interstate Park on the Virginia/Kentucky border. There they will be "hacked" with two other chicks and released in 2-3 weeks as part of our effort to restore falcons to their historic range in western Virginia. The other two Richmond eyases will remain here in the Falcon Pen to be attended by their parents. We likely will attach the trigger and release these falcons during the second week of August, depending on their development and on weather conditions. Stay tuned!