Colophon
The animal on the cover of Programming HTML5 Applications is the European storm petrel (Hydrobates pelagicus), also known as a stormy petrel. The name “petrel” is derived from Saint Peter, because the birds appear to walk across water—in reality, they are fluttering and pattering their feet just above the surface while looking for a meal. They are commonly found in flocks in the Atlantic Ocean and Mediterranean Sea, following ships to eat discarded food and even to take shelter on board in bad weather.
Storm petrels are the smallest European seabird, at about 15–16 cm in length with a 38–42 cm wingspan. Their plumage is primarily black, with a white rump and white coverts on the underside of their wings. Their beaks are thin and hooked, with a tubular nostril on the upper beak used to expel excess salt after drinking seawater. They have webbed feet and are able to swim, though they do not often dive for food, preferring to skim the surface of the water. The petrel’s diet consists largely of small fish, squid, plankton, and crustaceans, as well as offal left by fishing boats and other shipping traffic.
The storm petrel spends most of its life at sea, only coming to land for breeding season. In large colonies, the birds build nests on inaccessible rocky coasts and islands around the north Atlantic and western Mediterranean. During this time they are strictly nocturnal, to avoid predation from larger seabirds like gulls and skuas. They only lay one egg each season. In the winter months, they migrate to the oceans off of western and southern Africa.
Many 18th- and 19th-century sailors called storm petrels “Mother Carey’s chickens,” and believed the birds were the souls of dead seamen that warned of oncoming storms. Mother Carey is a supernatural figure who was said to live on an iceberg in the north and was thought responsible for storms at sea.
The cover image is from Cassell’s Natural History. The cover font is Adobe ITC Garamond. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont’s TheSansMonoCondensed.