Other examples include: 1  Some mating dances, commonly carried out by birds, are examples of fixed action patterns. 2  In these cases, the sign stimulus is typically the presence of the opposite sex. 3  Kelp gull chicks are stimulated by a red spot on the mother's beak to peck at the spot, which induces regurgitation.
Norwegian's 13-ship fleet sails all over the world, with 2015 itineraries lasting anywhere from one to 45 days. The cruise line's most popular routes include Hawaii, Alaska and the Caribbean, with home ports in U.S. cities like Honolulu, Los Angeles, Miami, New York and Seattle.
Carnival is the largest of the major cruise line companies, with 24 ships (compared to 22 for Royal Caribbean and just 13 for Norwegian) as well as the largest market cap ($37 billion).