Appearance

Orinoco Goose carries itself upright, and is identified by its off-white neck, breast and belly, black wings with a white speculum, orange and brown on flanks, and salmon legs. It vocalizes frequently in territorial displays and as contact calls between adults and young, having a range of calls from high whistles to guttural cackles and honks.

Males are noticeably larger than females, and perform territorial displays to protect nest-sites and to protect their mates from other males.

Orinoco Goose is larger than Black-bellied Whistling-Duck (Dendrocygna autumnalis), with entire head, neck and chest creamy white. The bill of the goose is mostly dark and short, easily distinguished from the uniformly red and proportionally larger bill of Black-bellied Whistling-Ducks. In flight, Black-bellied has white on forepart of wing, whereas the Orinoco Goose has white on the secondaries (Hilty and Brown 1986).

The following description is based on Restall et al. (2006); see also Blake (1977):

Adult male: Head, neck and breast to central belly offwhite, streaked slightly buffy on nape and scalloped on breast. Mantle gray scalloped white; band across upper mantle, scapulars, breast-sides and flanks orange. Wings black with broad white speculum. Large crescent of dark brown behind flanks. Undertail coverts white.

Female: Similarly patterned, but has drab wash to crown and back of neck; orange flanks less extensive; and dark post-flanks patch borders scalloping on sides to belly.

Unmistakable.

Non-breeding adults in the Venezuelan llanos are observed in large flocks during Feb - April in which some birds are missing primary and secondary wing features, suggesting that non-breeders do form molt flocks (Kriese, pers. obs.).

Unlike true geese, Orinoco Goose adults with young in Venezuela do not molt their wing feathers during the brood-rearing period.  It is unclear then if they molt during the non-breeding season (Kriese, pers. obs.).

There is no alternate plumage.

Iris: dark

Bill: Black above, red below.

Tarsi and toes: Bright salmon red in male, and slightly duller orange in the female.  Juveile individuals have duller color on legs and feet compared to adults.

Total length: 61-66 cm (Restall et al. 2006), 61-76 cm (Hilty and Brown 1986).

Linear measurements:

Below from Kriese (2004) and from Davenport, Nole, and Carlos (unpublished data):

Adult male:

tarsus length:  96.6 ± 1.7 mm

body mass:  1800 ± 54.0 g

Adult female:

tarsus length:  86.6± .7 mm

body mass:  1333.8 ± 47.5 g