Possible Clues:

• The Ancient Mariner got it in the neck
• Large oceanic bird
• Handicap: a golfing term
• Bird of the Ancient Mariner
• I take 1 across at sea in the Antarctic, under a pound
• Flyer unfortunately shot down by crew member
• Great shot required to get this bird
• Burdensome bird
• Three under for handicap
• Bird has a weight at sea