Breeding biology of the Crested Caracara in the Cape region of Baja California, Mexico

The breeding biology of the Crested Caracara (Caracara plancus) was studied during the 1990 and 1991 breeding seasons in Baja California Sur, Mexico. Sixteen nests were monitored in 1990 and six in 1991. The breeding season extended from February-August. Caracaras were more abundant during the post-fledging period (October-November) when up to 1.2 birds/km were registered in road surveys. The cardon cactus (Pachycereus pringlei) was the most used structure for nesting (76% of nests), although other tree-like structures were also used. Nest material consisted mainly of twigs of rama parda (Ruellia peninsularis), coralvine (Antigonon leptopus) and condalia (Condalia globosa). Nesting success estimated using the Mayfield method was 0.75 and 0.38 in 1990 and 1991, respectively Mean (+/-SD) productivity was 2.2 +/- 0.4 and 1.8 +/- 0.7 fledglings per successful nest in 1990 and 1991, respectively. Five second clutches were registered. The productivity of the Cape region Crested Caracara population was similar to that reported for caracaras in Texas but higher than in Arizona.