- Issue date: 4th May 1981
- two values in a se-tenant pair
- Designed by: Armando Ruiz Oteo
- Printed by: TIEV
- Print process: lithography
- stamp format height 40mm x width 48½mm
- Perforations: 14.0 x 14.0
12p muscovy duck, Cairina moschata
20p red-billed whistling duck, Dendrocygna autumnalis