Skuas and jaegers stercorariidae

The skuas are seabirds in the family Stercorariidae. The three smaller skuas are called jaegers in North America. They have even been sighted at the South Pole. 
 

Description:

These medium to large birds usually have a grey or brown plumage, often with white markings on the wings. The skuas range in size from 310 grams (11 oz), to   1.63 kg (3.6 lb). On average, a skua is about 56 cm (22 in) and 121 (48 in) across the wings. They have longish bills with a hooked tip, and webbed feet with sharp claws. They look like large dark gulls, but have a fleshy cere above the upper mandible.