Sharon Matola, Belize Coordinator
This is the most exciting Update since the start of the
Belize Harpy Eagle Restoration Program. The eagles, still
at their initial release site at Las Cuevas Research Station
(LCRS), are clearly showing signs of steady independence.
Besides documentation of their hunting, the Harpy Eagles
are also moving out further and further from the hack site.
Dispersal is a necessary activity, and shows that gradual
movements away coincide with becoming further independent
from their beginning site location at LCRS.
I have received questions about the general procedures
followed in the Belize Harpy Eagle Restoration Program,
BHERP. To address this, I have included a summary of the
procedures used and then I have followed this with a more
tailored briefing about the Belize program itself. As ever,
please feel welcome to contact me with questions or comments
A. GENERAL NATURAL HISTORY
The Harpy Eagle, Harpia harpyja, could, historically, be
found in healthy populations from southern Mexico to northern
Argentina. Due to extensive deforestation, human persecution,
and habitat fragmentation throughout its range, populations
have been drastically reduced and Harpy Eagles are considered
to be nearly extinct in Central America (Howell and Webb
1995). Current sightings of Harpy Eagles have been confirmed
in Panama, Costa Rica, Belize and Nicaragua. However, no
known breeding pairs exist in these countries at this time.
The Harpy Eagle is believed to be the most powerful raptor
in the world. It is the largest eagle in tropical America,
weighing 18-20 lbs. Its wingspan exceeds two meters. Unlike
many other raptors, Harpy Eagles do not soar high. Nor do
they fly long distances. Instead, they travel relatively
slowly, moving from tree to tree through the forest. They
are top predators and can live for over 50 years in captivity.
Harpy Eagles require large areas of intact lowland forest
in order to successfully hunt and reproduce. Because of
this, these raptors are considered to be an “Umbrella
Species” – in order to protect Harpy Eagles
it is necessary to conserve large tracts of forest and these
same forests contain some of the highest biodiversity on
Throughout the range of the Harpy Eagle, the forests supporting
their populations are usually less than 800 meters in height.
Undisturbed forests are ideally suited to their needs. They
have also been observed in areas with minimal sustainable
use, as well as in second growth forests. Most important,
the habitat requirements for Harpy Eagles include the presence
and availability of prey. Also necessary is an abundance
of large, emergent trees in which to build their nests.
The diet of the Harpy Eagle consists mostly of a variety
of medium-to-large sized arboreal animals. This also includes
other birds. Sometimes they will prey upon mammals and reptiles
that live on the forest floor.
B. THE HATCH – TO –RELEASE PROCEDURE
1. The Harpy Eagles are captive-bred in Panama by the Peregrine
Fund at the Neotropical Raptor Center. They are handled
no more than 4 times: A. when moved from the lab to the
imprinting chamber. B. then from the imprinting chamber
to the flight pen. C. followed by a move to the hack box.
D. finally, when they are relocated from the hack site to
the final release area. (one exception is for recapture
to change radio-transmitters)
2. After hatching, the chicks are kept in a lab where they
are fed and cared for during the first weeks of their lives.
At 30 days old, they are placed into an imprinting chamber
– a wooden box that is in full view of an adult Harpy
Eagles. This allows the young birds to imprint on their
3. At around 120 days of age, they are then moved to a big
flight chamber. This allows them the room to fledge naturally
and to exercise their wings.
4. At around 150 days of age, and after they spend about
4-6 weeks in the flight chamber, they are captured, weighed
and radio transmitters are placed on the birds. They are
then ready to go to their hack site – a modified chamber
built at a pre-selected, isolated location in a forest habitat
(Las Cuevas Research Station, for this particular project).
A wild Harpy Eagle begins to hunt at approximately 1 year
of age. The Peregrine Fund has also found that this is similar
to captive-bred and released eagles in Panama. Once a released
eagle is hunting, and does not require constant monitoring,
it will be trapped, then relocated to a final release area.
For the Belize Harpy Eagle Restoration Program this area
is the Rio Bravo Conservation Management Area, in northwestern
Belize, under the management of Programme for Belize.
C. SELECTION OF RELEASE SITES FOR CAPTIVE BRED
The principal consideration for release site selection
includes habitat structure, prey abundance, logistics to
the work site, and relative isolation from human activity.
D. INSTALLING RADIO-TRANSMITTERS
A small radio transmitter is attached to the birds to allow
biologists to track the Harpy Eagles once they are released.
The transmitter is glued with epoxy and cable-tied to the
upper (proximal) ventral part of the deck feather (middle
tail feather), and will be attached to the bird until it
molts. This normally takes a year.
E. FEEDING THE HARPY EAGLES AT THE HACK SITE
The Harpy Eagle monitors place food for the birds when
it is dark, either at night, or in the very early morning
hours before dawn. At the hack site, the attendants always
approach the hack box from the back so that the birds do
not see human activity.
The females usually consume more than the males. The eagles
receive one rat each day. Dead wildlife is NEVER given to
the Harpy Eagles. The cause of death of most wildlife cannot
be determined, therefore, it is risky to feed Harpies animals
which may have been poisoned, or died from a disease.
F. RELEASE FROM THE HACK SITE
In the wild, young Harpy Eagles generally fledge between
6 and 7 months of age. Given this, the young Harpy Eagles
are usually released from the hack box between 175 and 210
days of age. Work both in Panama and Belize has shown that
some of the eagles may come out of the hack box within seconds.
Others may stay in the hack box for hours. The birds are
G. FEEDING TREES
A feeding tree is basically a Harpy Eagle feeding station
located away from the hack box. This is done due to three
possible scenarios. 1. If the eagle leaves the hack site
and does not return within 7-10 days, monitors must set
up a tree for the bird to ensure that it is eating. In Panama,
it has been experienced that Harpy Eagles sometimes will
not return to the hack site and will feed only at the feeding
trees. 2. It is done to lure Harpy Eagles away from the
hack box. This ensures that the release area does not become
“crowded”. Also, it allows the release of more
birds at one site than normally would be possible. 3. If
a Harpy Eagle appears to be flying/dispersing, it can be
used to keep the bird in one general area.
H. DISPERSAL AND TRACKING
The young eagles will begin to range from the hack site
and may only return to the hack box every few days. This
does not mean that they are independent or dispersing. This
is a natural part of their exploratory nature. It exposes
them to prey sources, other raptors and also, unfortunately,
possible fatal experiences. In the wild, Harpy Eagles are
dependent on their parents for at least 2-3 years after
fledging. Therefore, observing tracking and identifying
each eagle is done with diligence.
I. POTENTIAL HAZARDS TO THE EAGLES
Experience from Restoration work in Panama has shown that
3-4 possible scenarios exist as potential hazards. First,
the birds could become increasingly used to humans as their
food provider and will not learn to seek and kill prey.
If this happens, they may never learn to hunt and could
potentially starve to death. While possible, this is unlikely
to happen. Second, it is possible that the released birds
may fall prey to another predator. This is most likely to
occur once the eagles are hunting for themselves, as they
can be caught on the ground while eating their quarry. Very
little can be done if this occurs and some natural mortality
must be anticipated. Third, if a resident Harpy Eagle pair
is in the released Harpy Eagle area, they could possibly
kill the birds – again, an unlikely scenario to happen
as part of the Belize Harpy Eagle Restoration Program. And
the fourth possible hazardous outcome would be a threat
from hunters who might shoot and kill the birds.
J. RELOCATION OF HARPY EAGLES
|By using radio-telemetry
to locate an eagle and a trap with bait, any released
Harpy Eagle can potentially be captured. This is done
by experienced personnel and only in circumstances when
the bird’s life is at risk, or if there is an
immediate need for relocation. Moving of the eagles
from the initial release site to the final release area
will take place by the fastest and least stressful means
of transportation. The eagles will be placed in large,
covered kennels and escorted by a biologist at all times.
The relocation area would be a large, suitable habitat
for Harpy Eagles, with potential prey items and emergent
trees.. Ideally, there would be a non-existing or low-density
population of wild Harpy Eagles to avoid possible intra-specific
FINE TUNING THE PANAMA WORK FOR BELIZE
The Belize Harpy Eagle Restoration Program, BHERP, is
part of a larger 25 year effort aimed at restoring Harpy
Eagles to a sustainable population throughout the MesoAmerica
Biological Corridor, MBC. Over this period of time, about
60 eagles are expected to be bred in captivity at the Neotropical
Raptor Center in Panama, and about 8 new breeding pairs
in key locations in the MBC will be established.
In Belize, this project aims to restore lost or depleted
populations of Harpy Eagles using captive breeding and release
methods that have been used to restore other endangered
raptors, such as the Peregrine Falcon and the Mauritius
Kestrel. The BHERP serves to empower biodiversity conservation
efforts by using the Harpy Eagle as an umbrella species.
Sustaining Harpy Eagle populations in a forested landscape
rich in its biodiversity, maintains these ecosystems in
a healthy state.
In the BHERP, it is aimed to annually release 4-6 Harpy
Eagles in the Rio Bravo Conservation Management Area. A
thorough assessment of the forest was undertaken to determine
the status of the prey base. Overflights were accomplished,
as well, to obtain a visual understanding of the amount
of forest area available for this important final release.
These fly-overs were made with assistance from LightHawk.
Most of these eagles will be released at approximately 2
years of age and will be independent of human care. At around
5 years of age, a Harpy Eagle reaches sexual maturity. Given
this, it will be another 3 years before the released eagles
are ready for breeding. As these first few years are critical
to the survival of the eagles (and as with most raptors,
a high mortality percentage should be expected, this has
been documented at 60-80%), a high number of Harpy Eagles
will need to be released in order to achieve a healthy number
of adult breeding pairs.
All of the released Harpy Eagles will be fitted with a VHF
radio transmitter. This allows their monitors to locate
them once they begin to disperse from the release area.
In addition, a small sample of birds will be fitted with
satellite transmitters (PTT). These units will assist in
the tracking of the birds and will allow a more precise
and regular understanding of their movement patterns.
To maximize the success of the release project, a crew
of 2-3 biologists will be part of the program. They will
monitor the behavioral patterns of the released eagles.
The information gathered will allow for making necessary
changes in the release strategies. The biologists will be
trained in radio tracking, observations and data collection
techniques. This training will occur prior to the release
of the Harpy Eagles. It will continue once they are in the
field. To assist, supervisors will conduct semi-regular
evaluations in order to insure that the work is being carried
out as needed. The country coordinator of the BHERP will
also make visits to the project site and provide assistance.
PROGRESS FOR THE BHERP SINCE JANUARY
In June, the 4 Harpy Eagles were trapped and new radio-transmitters
were placed on each bird. This will enable the biologists
monitoring the birds to obtain continual data on their ecology.
The Harpy Eagles initially released at LCRS, have shown
to be dispersing further and further away from their original
site of release. This mirrors the Panama project, and provides
a strong confidence level that the released birds will follow
a general time frame of release-to-dispersal behaviour.
In Panama, captive-bred and released Harpy Eagles have
shown to begin hunting independently at approximately 1
year of age. This, too, has been reflected in the BHERP.
Prey documented by the Harpy Eagles to date include:
- Kinkajou, Potos flavus
- Anteater, Tamandua mexicana
- Opossum, Didelphis marsupialis
Spider monkey, Ateles geoffroyi, and Howler monkey, Alouatta
pigra, are both present in the area, but have not been preyed
upon by the Harpy Eagles.
AT THE BELIZE ZOO AND TEC
“Panama”, the captive-bred Harpy Eagle at TBZ,
continues to be a popular attraction and education exhibit.
His lack of shyness around human visitors adds to the value
of his serving as an ambassador for the released Harpy Eagles
A new sign has been erected by his exhibit explaining the
probable prey choices for the released birds in Belize.
A few times, it has been overheard in presentations given
by tourguides to their clients that “Some people are
against Harpy Eagles coming back to Belize because they
will decimate our Howler monkey populations”.
The sign explains that these birds seek, for good reason,
solitary arboreal prey. Taking an Anteater or a Kinkajou
is far less risky than flying into a troop of Howler monkeys
for a meal. It has also been shown that male Howler monkeys
will attack back, and this is a threat which can greatly
endanger a Harpy Eagle (Touchton 2002). However, at some
times of the year, food resources for primates are at a
hard decline. When this occurs, the weaker members of the
troop will often fall behind. These individuals are likely
to fall prey to a predator. This is called “how nature
PROBLEMS AFFECTING THE PROGRAM
Unfortunately, there has been a marked increase of Guatemalan
incursions over the border and into the area around LCRS.
Their main purpose for entering Belize is to harvest “Xate”,
the leaf of a Chamadorea species of palm that is widely
used in the floral industry. However, they hunt, and they
have caused disturbances at LCRS. It is viewed that their
increased presence puts the released Harpy Eagles at serious
risk. At this time, a removal strategy is being considered
and the aim is to get the 4 birds to their final destination
at Rio Bravo Conservation and Management Area, as soon as
A lack of support funds is still causing problems for
the BHERP. Grants are pending, however, the project continues
to be hampered by funding gaps.
THE UNDP/GEF/SGF ENVIRONMENTAL EDUCATION PROGRAM
Thanks to a grant received by the United Nations Development
Programme, Global Environmental Facility Small Grants Program
UNDP/GEF/SGF, last year, our Education Department has put
forward a dynamite program which has seen an increase of
awareness about the Harpy Eagle communities in Belize.
The targeted communities have been in the Belize and Orange
Walk Districts, and the villagers have been Creole, Mestizo
and Mennonites. These villages lie closest to the forests
of Rio Bravo, the final destination site for the 4 Harpy
Eagles presently at LCRS.
Since hunting has been a major cause of the reduction of
Harpy Eagle populations throughout Central America, informing
these communities about the important role the Harpy Eagle
plays in the local ecology becomes critically important.
A total of 23 presentations were made throughout these communities,
and many of the participants came to The Belize Zoo to meet
and greet, “Panama”, the official Belizean Harpy
Eagle ambassador for his species “out there”.
The Education program has included the distribution of
colour posters and brochures as well as the production of
a short video about the program. The video, detailing the
exciting aspects of BHERP, has been shown nationwide in
Belize, and will continue to be shown on various television
stations, throughout the year.
UNFORTUNATE NEWS FOR THIS UPDATE RECEIVED 7 JULY
One of the male Harpy Eagles was found dead less than 2
km from LCRS. The cause of death, at this time, remains
unknown. The bird will undergo a necropsy and a report on
this will appear in a later update.
Given that mortality rate is expected to range about 60
percent in re-introduction programs, this event, while very
sad, is also part of the reality of assuming an ambitious
and complicated program such as the BHERP.
A great deal of collaboration and assistance is a continuing
part of this important conservation work. Special thanks
Biologists monitoring Harpy Eagle activity since last Update:
- Kevin Hall
- Phillip Hannon
- Todd Gillen
- Chris Hatten
The Belize Defence Force, BDF
The Peregrine Fund
Education Department, TBZ
Birds Without Borders/Belize
The Ministry of Natural Resources, Government of Belize
Las Cuevas Research Station
Programme for Belize
Richard and Carol Foster, Cinematographers
Howell, S.N.G. and Webb, S. A guide to the birds of Mexico
and northern Central America. 1995.
Touchton, J., Hsu, y and Palleroni, A. Foraging ecology
of reintroduced captive-bred subadult harpy eagles (Harpia
harpyja) on barro Colorado island, Panama. 2002.
Sharon Matola, Belize Country Coordinator
Back to main Harpy Eagle introduction
Update 2 of October 18, 2003
Update 3 of January 2004
Update 5 of December 2004