From the Guanacaste Journal: guaco

The Journal

The laughing falcon: A real threat to snakes



According to a study on birds of the Nicoya Peninsula, another key species that inhabits Guanacaste is the laughing falcon, known locally as guaco because the repetitive “wah-co” sound it makes — more like a lunatic laughter that goes on compulsively at dusk in lowland jungles.

This bird of prey is an important biological control agent, particularly because it feeds on snakes, which just can’t outwit the laughing falcons’ brilliant hunting skills, as they trap the reptiles and they hang them from their perches atop cenizaro, ceiba, tempisque and ojoche trees.

The laughing falcon measures approximately 53 cm (21 inches) in length and has an average weight of 600 grams.

Adults’ head, neck and lower part of the body are white, with a black mask that covers their eyes, cheeks and back of the neck. The upperparts are dark brown, black and pale yellow tails, and yellow legs. Juvenile guacos are mostly yellowish.

The laughing falcons’ preferred habitation sites are open areas of secondary forest growth, small forest patches, and savanna trees.

Their flight is sustained, with short flaps. They like to perch during long periods of time on long, exposed branches, as they search for food. It is at dusk when they offer their laugh-like songs most often.

As mentioned above, the main part of the guaco’s diet is snakes, which they trap with their densely scaled talons. After catching the reptiles, the falcon quickly decapitates them with their bills and takes the prey to its perch. Some of their victims include venomous coral snakes. Laughing falcons also feed on lizards and rodents.

Because it feeds on all these species, the guaco’s role in keeping the ecosystem’s balance is very important.

Laughing falcons breed during the dry season. They most often nest in cavities high up on tall trees, though they are known to sometimes nest in holes in cliffs — or take over the nests of hawks or crested caracaras.

This bird is a common resident of lowland areas on both the Pacific and the Caribbean. On rare occasions it can be seen as high up as 1,850 meters above sea level.

Unfortunately, populations of the laughing falcon are low in the Guanacaste Biological Corridor. Most of these birds have been spotted on the foothills of Cerro Cordones, in San Antonio de Nicoya. Likewise, they can be seen in the lowlands of San Pedro de Santa Cruz, particularly in pairs.

Very few of them can be spotted in other areas of Guanacaste, such as the Diria National Park, the Barra Honda National Park, and the Monte Alto Natural Reserve.