Herpetotheres

The laughing falcon (''Herpetotheres cachinnans''), also called the snake hawk (erroneously, since it is not a hawk), is a medium-sized bird of prey in the falcon family ( Falconidae), the only member of the genus ''Herpetotheres''. This Neotropical species is a specialist snake-eater. Its common and scientific names both refer to its distinctive voice.

Taxonomy

Its English name comes from its loud voice, as does the specific name ''cachinnans'', Latin for "laughing aloud" or "laughing immoderately". The generic name ''Herpetotheres'' refers to its preferred food; it is Latinized Ancient Greek, derived from '' rpeton'' (ἑρπετόν, " reptile") + ''therizein'' (θερίζειν, "to mow down").

Its relationships with other members of the Falconidae are unclear. Traditionally it has been placed in the subfamily Polyborinae with the caracaras and forest falcons, but the American Ornithologists' Union's North American Check-list Committee now places it in the same subfamily as the true falcons, while the South American Check-list Committee places it with the forest falcons but not the caracaras, and it has also been considered a subfamily of its own.Channing & HCT (1996)

Description

The laughing falcon is longJiménez & Jiménez (2003) and has a wingspan of . As usual among birds of prey, the females are bigger, weighing compared to the males' .

Adults have a pale buff head, changeable between a more brownish and an almost white hue according to feather wear and individual variation. The broad black face mask stretches across the neck as a narrow collar, bordered with white. On the crown, the feather shafts are dark, producing a somewhat streaked effect. The upper wings and back are blackish brown. The uppertail coverts are whitish buff again, and the rectrices are barred black and whitish, ending in white. The underside is uniformly pale buff; there may be a bit of dark speckling on the thighs, however. The underside of the wing is pale rufous-buff, sometimes with some dark spotting on the underwing coverts. The tips of the primary remiges are barred with pale grey below, their bases are quite rufous. The iris is dark brown, the bill is black with a pale yellow cere; the feet are also pale yellow.

Immature birds differ little from adults; they have lighter margins to the back feathers, producing a scalloped effect. The light parts of the plumage are almost white, paler than in adults; the unfeathered parts are also paler. Nestlings are covered in peculiarly dense down, reminiscent of a duckling's; they are generally brownish buff, darker above, and already show the blackish facial marks of the adults.

With its big white (immature) or pale buff (adult) head having a dark brown mask from the eyes around to the nape, it is unmistakable. In flight it shows a rufous patch near each wingtip (formed by the basal parts of the primaries) and a shape more like an ''Accipiter'' hawk than most of its falcon relatives, with short, rounded wings and a long tail.

Voice

The namesake call is a long series of separate, rather human-like cries, each one often rising sharply in pitch in the middle and sometimes falling sharply at the very end, changing from a "joyful" to a "sad" sound, and rendered as ''ha-ha-ha har-her-her'' or ''haww harr herrer''. The series may be introduced by faster ''hahahahahaha'' calls suggestive of maniacal laughter, particularly when the bird is startled. Sometimes two birds call together at different pitches and tempos, producing a striking off-beat effect.

The laughing falcon has another call, typically given at dusk. This two-note call is preceded by a series of ''gwa'' notes given every half-second or so. They become more emphatic and after some time change to a sequence of the ''gwa co'' call proper, with the first syllable higher in pitch than the second, but not differing in emphasis or volume. The ''gwa co'' call may be repeated 50 times or more. Sometimes, the initial calls are a ''oo oo-oo cow-cow-cow'', sometimes a descending ''gwaaaaaaa....''. On occasion, the two-syllable call is not given, and instead the simple ''gwa'' is repeated as often as the full call.

The familiarity of these sounds in the American tropics is attested to by such common names as ''acauã'' (Portuguese), ''halcón macagua'', ''guaco'', ''halcón guaco'', and ''guaicurú'' (Spanish), and ''guaycurú'' (Guaraní).

Distribution and habitat

It is found from both coastal slopes of Mexico through Central and South America south to the Peruvian Amazon and Bolivian Amazon region, practically all of Brazil, and northern Argentina and Paraguay, at altitudes up to (rarely to in Colombia), though it is often absent from mountainous regions. It occupies varied habitats, usually including at least scattered trees; it prefers humid regions to arid ones and tends to avoid closed forest. It is generally not bird migration, migratory, though in some areas it may make seasonal movements.

Behavior

The flight is slow, with quick, shallow wingbeats interspersed with glides; the bird rarely if ever Lift (soaring), soars. When it lands, it will jerk the tail forcefully just like a wagtail. A laughing falcon frequently and often conspicuously stays on a Perch (disambiguation), perch for hours, sitting upright and observing the ground alertly, sometimes flicking its tail or nodding, or moving around a bit on its perch with slow, cautious little steps. It is generally peaceful and unlike other falcons will not harm smaller birds.

Feeding

It catches mainly snakes, including venomous ones such as coral snakes, and also lizards, and, to a lesser extent, small rodents, bats and centipedes. The laughing falcon pounces on its prey from flight, often with an audible thud, and then biting it just behind the head, sometimes removing the head in the process. It carries the food to a perch to eat. It may carry small snakes in its bill and swallow them tail-first; big snakes may be carried head-forward in its claws, as an osprey carries a fish, and then torn to pieces.

Breeding

The laughing falcon breeds in rock crevices, tree cavities, or occasionally in abandoned nests of a ''Buteo'' hawk or Caracara (subfamily), caracara; in general however it does not even gather nesting material in significant quantities. It lays one or two eggs according to some sources, but according to others always just one. The eggs have heavy dark brown markings on a brown or whitish or pale buff background. The young are thought to leave the nest eight weeks after hatching. The breeding season has been given as April and May, though it may well vary across the large range of this species.

Culture

The Ch'ol Maya of Chiapas, Mexico, believe that the laughing falcon can kill poisonous snakes because the birds are healers that can cure themselves if they are bitten. Tzotzil healers imitate the call of a laughing falcon in order to cure a snake bite.Bassie-Sweet (2015)

Footnotes

References

*Bassie-Sweet, Karen (2015): "The Ch'ol Maya of Chiapas"; University of Oklahoma Press, Norman.
* Channing, Keith & Hawk Conservancy Trust (HCT) (1996).
* Cuervo, Andrés M.; Hernández-Jaramillo, Alejandro; Cortés-Herrera, José Oswaldo & Laverde, Oscar (2007): Nuevos registros de aves en la parte alta de la Serranía de las Quinchas, Magdalena medio, Colombia [New bird records from the highlands of Serranía de las Quinchas, middle Magdalena valley, Colombia]. ''Ornitología Colombiana'' 5: 94-98 [Spanish with English abstract]
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* Howell, Steven N.G. & Webb, Sophie (1995): ''A Guide to the Birds of Mexico and Northern Central America''. Oxford University Press, Oxford & New York.
* Jiménez, Mariano II & Jiménez, Mariano G. (2003): El Zoológico Electrónico &ndash

Version of 2003-AUG-01. Retrieved 2007-FEB-22.
* Lewis, Charlton T. & Short, Charles (1879): ''căchinno. In: A Latin Dictionary''. Clarendon Press, Oxford. HTML fulltext
* Stiles, F. Gary & Skutch, Alexander Frank (1989): ''A guide to the birds of Costa Rica''. Comistock, Ithaca.
* Remsen, J. V., Jr.; Cadena, C. D.; Jaramillo, A.; Nores, M.; Pacheco, J. F.; Robbins, M. B.; Schulenberg, T. S.; Stiles, F. G.; Stotz, D. F.; and Zimmer, K. J. Version (2008-12-22). A classification of the bird species of South America. American Ornithologists' Union
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* Woodhouse, S.C. (1910): English-Greek Dictionary – A Vocabulary of the Attic Language. George Routledge & Sons Ltd., Broadway House, Ludgate Hill, E.C
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External links

*

Photos, videos and observations
at Cornell Lab of Ornithology, Cornell Lab of Ornithologys Birds of the World
Laughing falcon videos, photos & sounds
on the Internet Bird Collection

{{Taxonbar, from=Q903642

Falconidae
Birds described in 1758
Taxa named by Carl Linnaeus
Birds of Mexico
Birds of Central America
Birds of South America