 Otters , grey seals , killer whales and harbour porpoises are frequently seen on and around Papa Stour . Atlantic puffin , Arctic and common tern , bonxie and Arctic skua , northern fulmar , common guillemot , razorbill , curlew , wheatear , ringed plover and great black @-@ backed gull all breed on the island , and numerous migratory species have been recorded . 
