ISOLATION AND DECLINE OF A POPULATION OF THE ORANGE-BREASTED FALCON

作者：Berry Robert B^*; Benkman Craig W; Muela Angel; Seminario Yeray; Curti Marta

来源：The Condor, 2010, 112(3): 479-489.

DOI：10.1525/cond.2010.100012

• Belize
• declining populations
• Falco deiroleucus
• Guatemala
• raptor management
• small populations

Probably always rare and local because of its ecology and specialized habitat, the small, isolated population of the Orange-breasted Falcon (Falco deiroleucus) in Belize and Guatemala, likely numbering fewer than 40 territorial pairs, appears to be in steep decline in Belize. Territory occupancy (n = 12 eyries) in the population we studied in Belize declined from 83% (1992 to 1997) to 54% (2003 to 2009), and occupancy in 2009 was only half the mean in the prior decade. Mean annual production of fledglings per territorial pair declined 35% from 0.77 to 0.50. Mean annual population productivity, which measures the combined effect of occupancy and fecundity, declined 57% from 0.90 to 0.38. In contrast, neither occupancy nor fledging success in Guatemala (n = 7 eyries) declined over the same time period. Historical records and recent surveys suggest that the Orange-breasted Falcon has been extirpated from much of Central America and southern Mexico and that its range is contracting in South America, despite large areas of apparently suitable habitat. We identify factors we think are contributing to this decline, especially human-related conflicts as well as competition for nest sites and depredation by increasing numbers of Black Vultures (Coragyps atratus). We suggest potential management solutions, including genetic restoration and the creation of safe harbors for nesting.

• 出版日期2010-8