Jon Atwood, PhD Department of Environmental Studies Observers at
the Kekoldi watchsite, in the Caribbean lowlands of Costa Rica,
monitor the highest concentration of autumn, southbound migrant
Peregrine Falcons (Falco peregrinus) in the world. Currently
little data exist on the migratory behavior of this species in
the tropics. During daily observations from 15 August-30 Nov
2005, I counted 2,344 peregrines as they passed within sight of
the Kekoldi Reserve. The majority of observations (91%) occurred
from 1-21 Oct. Most aged birds were adults. Of the juveniles
counted, the most were seen later in the season. Peregrines
relied primarily on circle soaring and passed predominantly
during midday hours, coinciding with the peak of thermal
activity. Flapping occurred most frequently early in the day,
decreased through midday, and then increased slightly in the
afternoon. The general daily flight path shifted from the coast
to inland as wind direction shifted from south to northeast.
Flight altitude was greatest du