5. Gannets

Northern gannets may be the most aggressive bird on earth.

Closely packed nesting pairs often engage in blood baths with their neighbours, especially early in the season when territories are being established. Unlike fledgling murres that venture to sea with their fathers, gannet fledglings go it alone. After three months in the nest, the fat-ladened young will stop accepting food from their parents and find their own way to the ocean.