Designed by Paul Smith 2006. This website is copyrighted by law.
Material contained herewith may not be used without the prior written permission of FAUNA Paraguay.
Photographs on this web-site were taken by Paul Smith, Hemme Batjes, Regis Nossent,
Alberto Esquivel, Arne Lesterhuis, José Luis Cartes, Rebecca Zarza and Hugo del Castillo and are used with their permission.
CRACIDAE - GUANS, CURRASOWS AND CHACHALACAS
Six species of this exclusively New World family occurs in Paraguay. They can be split into two subfamilies (see below). Superficially similar to other gallinaceous birds, the oldest fossils date back 50 million years. Neck long, head small, and bill short and chicken-like. At least some brightly-coloured naked skin is present on the head and/or around the bill. The tail is long and the wings are rounded and concave. Some species have modified outer primaries permitting the production of loud, mechanical, whirring noises during nuptial displays. Sustained flight is rare despite the well-developed breast muscles. Longer flights usually begin with a period of frantic flapping, followed by longer glides, the tail aiding manoeuvrability. Most species are arboreal, some are more terrestrial, but all species sometimes feed on the ground. Legs strong (more so in terrestrial species) and claws curved. Elongated hallux is the same length as the three forward-facing toes, an adaptation for perching in trees. When in the trees they move with a series of hops, often propelled by the wings. On the ground they walk gracefully with long paces. Modified, extended trachea with a looped structure lowers pitch and increases volume of vocalisations. Males possess a copulatory organ. All species nest in trees, laying a small clutch of unmarked eggs that are incubated exclusively by the female. Moult is extremely slow, affecting only a few feathers at a time. Males are larger than females.
Subfamily Cracinae: Currasows
Crax - Crested head and coloured wattles at base of bill. Large pelvis and heavy large bill. Mostly terrestrial in forested areas. Heavy-bodied with strong, long legs. Strongly sexually dimorphic.
Subfamily Penelopinae: Guans and Chachalacas
Some brightly-coloured naked skin on head and throat. Smaller pelvis and bill. Mostly arboreal. More slender, with weaker, shorter legs. No sexual dimorphism.
Ortalis "Chachalacas" - Small and dull-coloured. Sociable. Occurring in open or semi-open habitats. Lacks dewlaps or wattles.
Penelope "Guans" - Unspecialised, homogeneous group occurring in forested areas. Mostly dull and brownish with brighter naked skin on the face.
Pipile "Piping-Guans" - Plumage mostly black with some white. Naked and colourful throat and dewlap. Outer primaries sharply attenuated.
REFERENCES
Campbell B & Lack E 1985 - A Dictionary of Birds - T & AD Poyser.
del Hoyo J 1994 - Cracidae Handbook of the Birds of the World Volume 2 - Lynx Ediciones.
