English: Red-throated Loon
Russian: Краснозобая гагара
German: Sterntaucher
French: Plongeon catmarin
Mongolian: Улаангүеэт гахууна, Улааномруут ахууна
Japanese: アビ (Abi)

Body length: 55-67cm
Wing span: 91-110 cm

Habitat: Commonest loon in most regions. Breeds on often small and fishless pools on tundra or on forest bogs, commuting to larger lakes or coast for food.

Identification: Smallest loon, but only slightly smaller than Black-throated. Bill uptilted with straight culmen, usually held pointing slightly upwards. Forehead flat, and inclination to have angled hindcrown. Usually noticeably flat-chested (useful esp. at long range; Black-throated has prominent chest). In flight, look for slimmer neck; also more ‘sagging’ neck giving hunchbacked impression; bill often pointing slightly upwards even in flight; usually modest foot projection, making wings set behind centre (but a few have feet projection more, as on Black-throated); generally somewhat faster and deeper wingbeats than Black-throated in comparable winds; and rather common habit of moving head as if ‘calibrating vision’ (Black throated does this only infrequently).

• Adult summer: Rufous neck patch is dark, and can look black at a distance, so (pale) grey throat and plain upperparts best long-range marks. 
• Adult winter: In profile, more than half of neck is white, visible in flight too, and, seen from behind, some white visible on sides of neck (Black-throated usually entirely dark-necked from rear), and a little white surrounds eye; whole upperparts finely speckled with white. Flanks show as a complete pale band (mottled) above waterline (if any pale visible), usually not as a conspicuous white patch at rear.
• Juvenile: As adult winter, except white areas on head and neck have fine, dusky streaking  (often extensive) not pure white, and upperparts have duller, greyer speckling.
• 1st summer: Summer plumage only partial. Often twin dark stripes on foreneck in transition.