The outstanding production of young Harpy Eagles in 2002 at The Peregrine Fund’s Neotropical Raptor Center in Panama created the opportunity to experimentally release young Harpy Eagles into the wild to refine methods and test whether captive breeding and release could be used to help restore lost or depleted populations of this large forest raptor. We have focused species restoration on the Mesoamerican Biological Corridor of Central America where loss of Harpy Eagles has been most significant and because the countries involved, working together as part of the Central American Commission on Environment and Development/Comisión Centroamericana de Ambiente y Desarrollo, have pledged to help restore Harpy Eagles and the biodiversity of their rain forest habitat. We have focused our efforts initially in suitable, Harpy Eagle depleted habitat in Panama and Belize, where strong partnerships with local government and non-governmental organizations have been critical for success. In Panama we cooperate with Autoridad Nacional del Ambiente ('www.anam.gob.pa), Autoridad del Canal de Panama (www.pancanal.com), Smithsonian Tropical Research Institute (www.stri.org), City of Knowledge, and many other individuals and organizations. In Belize we partner with The Belize Zoo (www.belizezoo.org), Las Cuevas Research Station (www.nhm.ac.uk/botany/lascuevas/index.html), Wildlife Division in the Department of Forestry (www.belize.gov.bz/), and others.
Harpy Eagle Release or “Hacking” is a Process
Eaglets hatched at The Peregrine Fund’s Neotropical Raptor Center (NRC) in Panama spend the first five months of their lives under the care of NRC staff. Once they leave the immediate protection of their eggs, they are placed in brooders where they are cared for and hand fed for the first few days until strong enough to feed themselves. After one month, these young birds are moved to an imprinting chamber. There, they remain in full view of an older Harpy Eagle. This allows the eaglets to naturally imprint on their species while slowly maturing and growing stronger. At four months of age, the eaglets are transferred to a large flight chamber, where they usually will fledge (fly for the first time). Around this time they are also fitted with an identifying band, and later, back-pack and tail mounted radio transmitters that allow us to find the birds in the rain forest once they are flying free in the wild.
 | | Harpy Eagle chick in an imprinting chamber. |
Their final move, at five months of age, is to the release site where they are housed in a “hack box,” a specially designed aviary built atop a tower in an isolated tract of forest. The young birds spend from three to four weeks in the hack box, which gives them time to become accustomed to the area around them while being protected from potential predators. While the birds are there, our “hack site attendants,” volunteers and staff, feed and observe the birds daily. Because it is important to prevent the birds from becoming too tame or associating humans with food we only make observations from a blind, so they are unaware of our presence. We always place food in the hack box at night so that we are least visible to the Harpy Eagles, and we only approach the hack box from the back which is made of sheet metal to create a visual barrier. These precautions help keep the eagles wild and help them to develop a natural fear of humans, which is critical for their survival wherever humans may persecute them.
 | | Young Harpy Eagle in a hack box. |
Release day is always a special day. Well before dawn, we carefully place food in front of the hack box and open the door. The birds don’t usually stir until after sun up when they discover their new freedom. Usually, their first activity is to eat the food we placed the night before, and then, over the next few days they begin making exploratory flights into the trees nearby. The birds remain dependent on the food that we provide for at least another seven or eight months. We provide them food in “feeding trees” near the hack box to which they habitually return. To make sure they are feeding and remain healthy we track them by following their radio transmitters as they explore and learn to hunt. This is their most vulnerable time when they can become prey to other predators or suffer a lethal injury from their own attempts to catch prey. In the wild, only about 10 to 30% of eaglets usually survive to become adults so some mortality at this vulnerable stage is expected. Occasionally a bird will suddenly and unexpectedly fly several miles from the release site and must be tracked, captured, and returned to the release area so that we can continue to feed it. Once we are certain they are hunting successfully on their own and are completely independent of human care, we capture them and re-release them into more isolated forests within Central America.
 | | Young Harpy Eagle following release from the hack box. |
Releases in Panama
Harpy Eagles need large tracts of undisturbed forest in which to hunt and nest. They feed mainly on arboreal mammals such as sloths and monkeys, but will also feed on iguanas, and other mid-sized mammals and reptiles. To find suitable release habitat, The Peregrine Fund biologists keep several factors in mind, including previous confirmed sightings of Harpy Eagles, present land conditions, and prey diversity and abundance.
Two additional factors are important for successful “hacking” of Harpy Eagles. The area must be relatively isolated from humans and human activity to reduce the possibility of eagles either becoming habituated to people or being persecuted by people. Despite being isolated, the area must also be readily accessible to our hack site attendants who provide food for and track the eagles daily. These conditions are difficult to find together in one place, but Panama’s Soberania National Park, located just outside of the country’s capital, proved ideal.
In 2002 we established a permanent release site in the park. We refurbished an abandoned cabin in the middle of the park to house our hack site attendants and built two hack boxes nearby that each house up to two Harpy Eagles. Living conditions are “primitive” for the attendants, many of whom are volunteers who spend six months or more at the site caring for the eagles. Although only about 20 km (12.5 miles) into the park, the drive along “Pipeline Road” (famous for its birding opportunities) can take two hours or more in the wet season and the road and bridges need constant repair and maintenance from our staff and others who use the road to enter the rain forest for research. The survival of released Harpy Eagles depends on them not seeing and becoming accustomed to humans. For this reason, all release sites on Pipeline Road in Soberania National Park are clearly marked and are not open to visitors. Researchers and others using Pipeline Road are requested to respect this critical need.
We are pleased with the results of the release program so far and have learned a great deal already, but we can not claim success until we confirm that adequate numbers of birds that we have released are breeding in the wild. Because Harpy Eagles take five or more years to mature, we can not expect this important event to occur for the first time until 2007, at the earliest. Clearly, we have much to experience and learn in the intervening years. To keep our readers up to date, we will post release results and describe any important events as they occur in the tables below.
Release results in Soberania National Park hack site:
| Number of Harpy Eagles released (cumulative) | 20 | | Number of Harpy Eagles currently at the release site | 14 | | Number of released Harpy Eagles hunting on their own | 4 | | Number of Harpy Eagles recaptured and released elsewhere | 1 |
Important events at Soberania National Park hack site:
| First Harpy Eagle moved to hack site | 14 August 2002 | | First Harpy Eagles released | 3 September 2002 |
| Released Harpy Eagle killed by Ocelot | 14 February 2002 | | Released Harpy Eagle killed by Jaguar | 7 March 2003 | | First Harpy Eagle seen feeding on her own prey, coatimundi and tamandua | April 2003 |
Released Harpy Eagle dies--snake bite suspected | 28 January 2004 | | First Harpy Eagle recaptured and hard released | 1 June 2004 |
Important events at the Chiquibul Forest hack site:
| First Harpy Eagles moved to hack site | 20 March 2003 | | First Harpy Eagles released | 12 April 2003 | | First Harpy Eagle seen with her own prey--a kinkajou | December 2003 | | Released Harpy Eagle dies--Unknown cause | 6 July 2004 | | First Harpy Eagle recaptured and released elsewhere | 10 August 2004 |
Visitor Information
One of the key criteria for the survival of the young Harpy Eagles and success of the release program is to prevent them from seeing and becoming accustomed to humans. For this reason, all release site areas, both in Panama and Belize, are clearly marked and are not open to visitors.
In Panama, visitors are encouraged to visit Summit Botanical Gardens and Zoo (Jardín Botanico Summit). Two adult Harpy Eagles are housed in a large enclosure that is open for public viewing. The Harpy Eagle Exhibit also includes a number of displays, videos, dioramas, and other educational material.
In Belize, visitors can see a young male Harpy Eagle at the Belize Zoo that hatched at The Peregrine Fund’s Neotropical Raptor Center in Panama. He hatched blind in one eye and was therefore un-releasable. He was donated to the Belize Zoo for public education and now acts as an “ambassador” for his species, helping to gain support and protection for this majestic raptor and the Harpy Eagle restoration program in Belize.
 | | A released Harpy Eagle |
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