The American Eagle Foundation (AEF) has experienced another good season of captive breeding and releases of bald eagles from its Douglas Lake hack site. The total of seven bald eagle releases included:
- A bald eaglet hatched in a wild nest in Marion County, TN (near Chattanooga) on approximately February 8, 2012, which was an extremely early hatch for Tennessee. It fledged from its nest about April 19, but was soon found in a weakened condition on the ground. It was taken to the AEF for rehab and placed in the Douglas Lake hack tower on May 23. It was released into the wild on June 5, 2012 at 16.9 weeks age. It was a male and weighed 6 pounds 12 ounces one day prior to release. Its left wing tag, with 2-inch high orange digits is “B2”.
- The Wildlife Sanctuary of NW Florida in Pensacola captive-bred two bald eaglets, which hatched there on March 19 and 23, 2012. They were placed in the Douglas Lake hack tower on May 8 at 6.9 and 7.4 weeks age. They were released on June 20, 2012 at 12.7 and 13.3 weeks age. They were both males and each weighed 8.0 pounds at release. Their left-wing tags are C2 and D2, respectively. The eagle “C2” was photographed in good condition on August 7 and 15, 2012 on Lake Pymatuning in NW Pennsylvania (near Ohio border).
- AEF’s Ms. Jefferson and Isaiah hatched one bald eaglet on April 11 . It was transferred to the Douglas Lake hack site on June 1 at 7.3 weeks age. It was released on July 15, 2012, with left wing tag E2. It weighed 9 pounds 13 ounces.
- AEF’s Independence and Franklin hatched three eggs on May 7 (2 eaglets) and May 8 (1 eaglet), as viewed on AEF’s live eagle nest cam at www.eagles.org. They were transferred from the Dollywood Park to the Douglas Lake hack site on June 22, 2012, when their ages were: 1 @ 6.4 weeks and 2 @ 6.6 weeks. Left wing tags F2, J2, and L2 were placed on the tree. F2 (named Ranger), fledged from the hack tower on 8/13/12 at 14.0 weeks age. J2 (BraveHeart) fledged 8/15/12 at 14.3 weeks age. L2 (Griffith) fledged 8/15/12, but promptly suffered an abrasion on its foot. L2 was recaptured and rehabbed at AEF and re-released from the Douglas Lake hack tower on 9/29/12 at 20.6 weeks age.
From 2002 through 2012, Independence and Franklin have produced captive-bred 27 eaglets. An awesome 26 of the 27 eaglets have been released from Douglas Lake hack site through 2012. One of the 27 was killed in the hack tower by a raccoon in 2010.
The 25-foot high hack tower on Douglas Lake has four hack cages. Each cage is 8x8x8-feet and can accommodate up to 3 eaglets at a time, or a total of 12 in all four hack cages. The eagles are released at approximately 13 – 14 weeks age, when they are first capable of flight. They then already have a full adult size, with a wing span of 6.5 to 7.5 feet. The principle behind hacking is that Bald Eagles tend to return to nest in the region of their first flight.
Eaglets from off-Park aviaries are transferred to the hack tower at approximately 8 weeks of age. Eaglets from AEF’s on-Park (Dollywood) aviaries are transferred to the hack tower between by approximately 6 weeks age. After that age, the eaglets may be able to see over the tops of their nests and could possibly become too accustomed to people for developing good survival skills.
AEF has successfully hacked and released 119 young bald eagles at its Douglas Lake hack site from 1992 through 2012, or an average of 5.7 bald eagle releases per year.
Due primarily to the effects of the insecticide DDT, there had been no successful bald eagle nests in Tennessee from 1961 to 1983. In order to restore natural nesting, the Tennessee Wildlife Resources Agency (TWRA), AEF, and its partners will have released 344 young bald eagles from 7 statewide hack sites from 1980 through 2012. The number of successful nests has gradually increased through 2011, when approximately 180 young were fledged from at least 110 statewide nests. TWRA, which is the primary monitor of wild nests, projects a significant increase in successful statewide nests in 2012.
Bald eagle hack releases may impact nesting recovery over a broad geographical area. They tend to return to nest after about five years age within about 75 miles of where they learned to fly. However, juvenile bald eagles wander over many states and southern Canada. If they happen to mate with an eagle that learned to fly at a distant site, they need to compromise on a permanent nest location. Tennessee-hacked bald eagles have nested at least as far north as near Lake Erie in northern Ohio, and in mid-Indiana.