Reserva Ecológica Costanera Sur

Sitio realizado por aficionados a la observación de aves desde 10 de enero 2006

Spurs

Spurs are bony projections occurring on legs and wings of birds. Those on the legs are known as tarsal spurs and most galliform birds bear this type of spurs. Wing spurs form in the area of the carpal joint (roughly expressed our wrist) and mostly emerge from the carpometacarpus, an oval-like bone which correspond to our palm and wrist bones.
Spurs are conical and may be slightly curved. They are covered with a sheath of horn which molts periodically. They are used as defence or offence weapons by exhibiting them to intimidate or hurt if necessary. They differ in size according to the species and sex.
Birds with wing spurs are found in the orders Anseriformes and Charadriiformes. In the reserve they are represented by the Southern Lapwing, the Wattled Jacana (Charadriiformes) and the Southern Screamer (Anseriformes). The distinctive fact is that screamers bear two spurs. The main one extends from the proximal part of the metacarpal bones and a smaller one, from the distal end. Miden 35 y 15 mm respectivamente y tienen una punta muy aguda y dos filos laterales cortantes.





Chajá/Southern Screamer© J. Simón Tagtachian