Pilot whale

Pilot whales are two species of oceanic dolphins, whose scientific name is Globicephala. The two types of pilot whales are the long-finned pilot whale and the short-finned pilot whale. Their behaviour resembles that of the larger whales more than that of dolphins. 
The two look similar at sea and are usually just known simply as pilot whales or "calderón" in Spanish. They and other large dolphins are also known as blackfish.
Pilot whales can be found nearly worldwide. The long-finned variety prefers colder waters, for example near Antarctica. The short-finned ones can also be found in tropical waters. Pilot whales are highly social animals, they live in groups of 20-30 animals, called "pods". Larger groups of over 100 pilot whales have been observed. Studies suggest that the young remain in the same pod as their parents, which is unusual for mammals. Female short-finned pilot whales go through menopause. Females that no longer reproduce contribute to the survival of the young.
For reasons which are unknown, pilot whales seem to end up stranded on a beach fairly often.