Petrel

The Petrel is an oceanic bird mentioned in the How to Train Your Dragon Book series.

Description
The term 'Petrel' most birds in the Order Procellariiformes, except the Family Diomedeidae, which are the albatrosses. Petrels are sometimes referred to as 'tubenoses', because they have a tubular nasal passage for smelling within their bill. All petrels live and feed out on the open ocean, eating fish and marine invertebrates. Occasionally some species may eat carrion. Petrels are so suited for life at sea and on the wing that many species cannot actually walk and must crawl or shuffle. Petrels generally only return to land to breed and lay eggs. Typically they stick to remote islands, and congregate in colonies. Most species mate for life and typically only attempt to lay and raise a single egg in a year.

Family Hydrobatidae or Northern Storm Petrels, mostly live in the Northern Hemisphere. Historic Vikings most likely encountered the European Storm Petrel (Hydrobates pelagicus).

Function
In the Book series, petrels are mentioned as a metaphor for comparison to something else.

In reality, many cultures throughout history have opportunistically hunted petrels for food.