Ross's Goose

The Ross's goose, Anser rossii, presents a striking figure with its pure white plumage contrasted by black wingtips. This diminutive goose, the smallest among North America's white geese, is easily distinguished by its relatively short neck and compact body. A characteristic feature is its short, triangular bill, tinged with blue and adorned with warty structures that become more pronounced with age. Adult Ross's geese boast all-white secondary feathers, while the juveniles display dark centers. The legs of these birds transition from olive gray in goslings to a deep red as they mature.

Identification Tips

To identify the Ross's goose, look for a rounded head perched atop a short neck, and a proportionally small bill without the "black lips" seen in the snow goose. Males are slightly larger than females, with the former reaching lengths of 23.2-25.2 inches and wingspans of 44.5-45.7 inches. Females are typically 6% smaller. The rare dark phase of this species is exceedingly uncommon.

Habitat

The Ross's goose breeds in the central Arctic's flat plains, amidst rock outcrops, drumlins, wet meadows, and marshy tundra. The landscape is dotted with dwarf birch, willow, grasses, sedges, and an array of low-growing vascular plants such as crowberry, lapland rosebay, and lousewort.

Behaviour

These geese are social birds, forming large nesting colonies on islands within shallow lakes and on adjacent mainland. They construct ground nests from twigs, leaves, grass, moss, and down. Females lay an average of 4 eggs per clutch and incubate them for 21–23 days. Ross's geese are migratory, departing Canadian breeding grounds by mid-October and returning from mid-April to May. They are grazers, feeding on grasses, sedges, and small grains, often in large mixed flocks with snow geese.

Song & calls

The vocalizations of Ross's goose can be heard on xeno-canto, where one may listen to the calls that punctuate the Arctic air.

Breeding

Ross's geese breed in large colonies, with females diligently incubating their clutch of approximately 4 eggs for three weeks. The nests are a simple affair, lined with down for insulation.

Similar Species

The Ross's goose is often mistaken for the white-phase snow goose, which is approximately 40% larger. The snow goose also has a larger bill with distinctive black coloration, which the Ross's goose lacks.

Diet and Feeding

Ross's geese are herbivores, grazing on a diet of grasses, sedges, and occasionally small grains. They forage in large flocks, often alongside snow geese, taking advantage of the abundant vegetation in their Arctic and migratory habitats.

Conservation status

Once considered rare, possibly due to overhunting, the Ross's goose has made a remarkable recovery. Thanks to conservation efforts, it is now classified as Least Concern by the IUCN and is protected under the Migratory Bird Treaty Act. The population has increased dramatically, and the species is no longer in immediate peril.