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)
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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, M�xico. 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 M�xico, 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 M�xico, 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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