Anatomy:
Toothed whales have a single blowhole on the top of the head (while the baleen
whales possess two of them). Except for the sperm whale, most toothed whales
are smaller than the baleen whales. The teeth differ considerably between
the species. They may be numerous, with some dolphins bearing over 100 teeth
in their jaws. The other extremum are the Narwhal with its long tusk and the
almost toothless beaked whales with bizarre teeth only in males. Not all species
are believed to use their teeth for feeding. For instance, the Sperm Whale
is likely to use its teeth for aggression and showmanship.
Behaviour:
Vocals
Vocalizations are of great importance for toothed whales. They maintain a
broad variety of calls to communicate, but also are capable of using ultrasound
for echolocation.
Movement:
Most toothed whales swim rapidly. The smaller species occasionally ride waves,
like the bow waves of ships. Most frequently can dolphins be encountered this
way. They are also famous for their acrobatic breaching from the water, e.g.
the Spinner Dolphin.
Social behaviour:
Generally toothed whales live in groups of up to a dozen animals. These so-called
schools occasionally can join, forming bigger aggregations up to thousands
of whales. Toothed whales are capable of complex interactions, e.g. cooperative
hunting. In captivity some species display a high potential for learning;
for this reason they are considered being among the most intelligent animals.
Human Impact
The Sperm Whale has been hunted commercially for long times (see whaling).
While small whales like the Pilot Whale today are still being pursued, the
main threat for most species is bycatch. Especially during the tuna fishery
thousands of dolphins drown each year.
Keeping small whales (mostly Bottlenose Dolphins, Orca or Belugas) in captivity
is a great attraction for ocean parks and zoos. However, it is controversial
because of the marine mammals' need for large spaces.
