Brant Goose
Branta bernicla
The brant is a small goose with a short, stubby bill. It measures 55–66 cm (22–26 in) long, 106–121 cm (42–48 in) across the wings and weighs 0.88–2.2 kg (1.9–4.9 lb). The under-tail is pure white, and the tail black and very short (the shortest of any goose). The body of the dark-bellied nominate subspecies B. b. bernicla is fairly uniformly dark grey-brown all over, the flanks and belly not significantly paler than the back. The head and neck are black, with a small white patch on either side of the neck.
ID text from Wikipedia, CC BY-SA 4.0

Nene
Branta sandvicensis
The nene is a large-sized goose at 41 cm (16 in) tall. Although it spends most of its time on the ground, it is capable of flight, with some individuals flying daily between nesting and feeding areas. Females have a mass of 1.525–2.56 kg (3.36–5.64 lb), while males average 1.695–3.05 kg (3.74–6.72 lb), 11% larger than females. Adults have a black head and hindneck, buff cheeks, and a heavily furrowed neck. The neck has black and white diagonal stripes. The adult's bill, legs, and feet are black.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: Brant Goose and Nene.