The Aplomado Falcon (Falco femoralis) is so rare in Costa Rica that the first edition of the standard Costa Rican field guide (Garrigues & Dean, 2007) did not even show an illustration of this species. At that time only three recent reports were known , all from Palo Verde in Guanacaste in the north-west. Earlier still, when Stiles & Skutch published their classic A Guide to the Birds of Costa Rica (1989), only one sighting had been confirmed.
However, in mid-July of this an immature bird appeared on the west side of the city of Cartago at Coris. The bird has remained at or near that location up until the present date and has been seen by numerous birders. I myself took the opportunity to visit the area and failed to find the bird on the first occasion. On my second visit, however, there it was, perched in the top of a cypress tree. Since this falcon hunts from an exposed perch it really was not surprising that I was able to locate it.
According to reports it has been hunting Great-tailed Grackles and Melodious Blackbirds, among other bird species, thus giving aid, however slight, to native bird populations. The two aforementioned species are fairly recent invaders from the north and are major indicators of deforestation. On my visit the falcon flew down very slowly from the cypress and perched nicely on a post only a few feet above the ground, affording an excellent view from close proximity. After a while it flew off, this time rapidly, and attacked a Yellow-headed Caracara (Milvago chimachima) before settling on another high tree snag.
To complete this post, here’s a photo of said caracara, a species whose range in Costa Rica is rapidly expanding: