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.
ANHIMIDAE - SCREAMERS
Two species of large, study waterbird weighing up to 5kg. Body extremely heavy and stocky, thick neck, but tiny head and chicken-like bill. Despite apparent bulk, the bones are highly-pneumatised and air sacs under the skin further increase lightness. They have long, broad wings and as a result they are skilful and graceful in the air, often soaring to great heights. Long, sturdy legs with disproportionately huge feet. Three front toes basally webbed with vestigial membrane. Hind toe elongated and not raised. Screamers are capable swimmers though they rarely do so. The tongue is horny. Long curved spur protrudes from wing bend, likely used in intraspecific conflicts. There is no copulatory organ. Uniquely Screamers lack feather tracts, with feathers growing evenly across the body. Another unique feature is the lack of uncinate processes, bony growths that strengthen the rib cage in other birds. Moult is gradual and there is no flightless period. Solitary breeders. Males slightly larger than females.
REFERENCES
Campbell B & Lack E 1985 - A Dictionary of Birds - T & AD Poyser.
Carbaneras C 1992 - Anhimidae Handbook of the Birds of the World Volume 1 - Lynx Ediciones.
