Sailors believe that seeing an albatross while at sea is a sign of good luck, while killing one spells doom and despair. The mighty albatross often flies alongside ships hoping to get ahold of some tasty garbage or scraps upon which it can feast. It's particularly persistent when compared to other birds and will continue following ships long after others have given up and turned back toward dry land.
Legend has it that these birds feel such affinity for ships because they contain the souls of drowned sailors, so killing one is akin to killing a fellow seaman [source: Webster]. Anyone who kills one of these birds is doomed to bear a tremendous burden – or hang an albatross around his neck – a fate masterfully illustrated in Coleridge's poem "The Rime of the Ancient Mariner." The superstition may not be as prevalent these days, when modern instruments and technology make humans less reliant on birds while at sea, but the idiom of hanging an albatross around one's neck has spread beyond the seafaring world to become a common expression representing a heavy burden.