Common minke whale calls were recorded from October to May – peaking in March – and had a source level of about 150 decibels at a reference pressure of one micropascal at one metre. Their source remained a mystery for decades. By the early 1980s they were thought to come from whales, but it wasn't known what species. In the early 2000s, it was suggested these sounds might originate from minke whales, based on their similarities to vocalizations produced by Southern Hemisphere forms. Finally, during a 2002 HICEAS ("H"awaiian "I"slands "C"etacean and "E"cosystem "A"ssessment "S"urvey) survey, the R/V "David Starr Jordan", using a
Creature type (Dungeons & Dragons) all animal type monsters are based on real world animals. Creature entries based on mythological, fictional, or nonexistent animals are usually classified as magical beasts (see below). Besides ordinary fish, birds, reptiles and mammals, the animal type is also applied to depictions of dinosaurs, prehistoric animals, and "dire" or specially modified, often larger and scarier, versions of real world animals. Some real world animals are not given the animal type in the game. Examples include arthropods (insects, spiders, etc.) and worms, which the game classifies as "vermin" (see below) and not animals. Mollusks, such as octopuses, are often classified as