Black-throated Diver
Gavia arctica
Length 60-70cm

Large, robust water bird which swims buoyantly. Dives well and often for fish. In summer, unmistakable with blue-grey head and nape, black throat and black and white stripes on side of neck. Belly and underparts white, wings and upperparts black with chequerboard of white spots on back. Sexes similar. In winter, has mainly blackish upperparts and white underparts; white 'thigh' patch often visible at water level. Rare breeding bird on lochs in W Scotland. In winter, more widespread in coastal waters around Britain; rarely on inland reservoirs.