MAYA PROJECT RESEARCH
Description and Results
The following account of our research activities follows the
outline given. For each topic, we describe the associated
conservation challenges, give some background knowledge on the
topic, describe our research activities, and give a brief
synopsis of our results.
8. Monitoring Population Status of Vulnerable and Threatened
Species
Species whose populations are endangered, threatened, or
vulnerable clearly merit special monitoring. In our project
area, two raptor species merit special attention because they
are intrinsically rare, patchily distributed, and/or declining
in number. These are the Orange-breasted Falcon (Falco
deiroleucus) and the Harpy Eagle (Harpia harpyja).
Here we describe our efforts with these species.
Orange-breasted Falcon (Falco deiroleucus)
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Orange-breasted Falcon (Falco deiroleucus)
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The Orange-breasted Falcon is one of the world's least known
and possibly rarest falcons. Though occurring from Guatemala and
Belize to northern Argentina, this falcon is nowhere known to be
abundant; it is patchily distributed, and seemingly rare in most
areas. These falcons appear to be reliant on mature forest and,
at least in Central America, nest mainly on large cliffs, which
are rare landscape features. These attributes combine to make
this mysterious bird inherently vulnerable, and possibly
deserving of some level of official listing.
The Peregrine Fund's attention to wild populations of the
Orange-breasted Falcon began in 1979 when Peter Jenny and
coworkers searched for wild pairs in Guatemala, Belize, and
Ecuador, finding several pairs and making initial field
observations.
In 1991 we renewed our attention to wild populations, and
began an intensive effort to find and study nesting pairs in
Guatemala and Belize. From 1991 to 1997, we found and monitored
the status of 19 nest sites in Guatemala and Belize, the largest
aggregation of nest sites known anywhere.
These efforts, conducted by Aaron Baker with the assistance
of Oscar Aguirre, resulted in a report on the species'
population status and reproductive trends in these two countries
over the 6-year period from 1992 to 1997 (Baker et al.
2000).
Aaron found no indication of declines of eyrie site occupancy
or reproductive rate during this 6-year period. However, we
consider it likely that Guatemala and Belize are home to fewer
than 50 breeding pairs of Orange-breasted Falcons, and certainly
fewer than 100. Recent searches by Peregrine Fund workers from
Honduras and El Salvador south to Panama encountered none of
these falcons except one or more pairs in Panama. Hence we
consider it prudent to consider the Guatemala/Belize enclave as
a small, intrinsically vulnerable population, disjunct from the
rest of the species' breeding range.
The main threat to this species is almost certainly
deforestation, especially in areas where forest occurs in
conjunction with large, traditional breeding cliffs. We know of
no evidence that chemical pollutants are affecting breeding
success, but the possibility of such effects should perhaps not
be ruled out.
We see a need for additional research on this species'
distribution, population size, and population tendencies
throughout the species' range. Whether it is relatively common
anywhere within its large South American range is unknown, and
no reliable estimate of the global population size can currently
be made.
Harpy Eagle (Harpia harpyja)
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This Harpy Eagle (Harpia harpyja) was
killed near the Guatemala/Belize
border in the year
2000.
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The Harpy Eagle, the world's most powerfully armed bird of
prey, historically ranged from northern Argentina to southern
Veracruz, México. While still occurring in large areas of rain
forest throughout much of this historic range, these eagles have
declined and even disappeared in many areas. Declines have
probably been due both to deforestation and shooting.
Our concern here is with the Harpy Eagle's population status
at the northern extent of the species' range, in México,
Guatemala, and Belize. Since the 1988 inception of the Maya
Project, we have sought reliable evidence of historic and recent
occurrences of this species in the region. We have gathered
evidence of several recent wild specimens, and are currently
preparing a publication regarding the species' status in Belize
and Guatemala, through collaboration with Robin D. Bjork (Oregon
State University and Wildlife Conservation International) and
Lee Jones in Belize.
The main point we wish to make here is that wild populations
of Harpy Eagles do still occur in México, Guatemala, and
Belize. It may yet be possible to save this eagle in the wild at
the northern extreme of its range.
 Literature Cited, Monitoring Population Status of Vulnerable and Threatened
Species
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