Main Points:

There are 2 “sub-orders” of cetaceans: odontocetes and mysticetes.

Odontocetes:

• There are two families of odontocetes distinguished by the shape of their teeth: the porpoises (with spade-like teeth) and dolphins (with round teeth).
• Sperm whales are the only odontocetes that don’t fit into either dolphin or porpoise categories.
• Odontocetes are pack animals that hunt cooperatively.
• Odontocetes use high frequency vocalizations for echolocation and “bio-sonar.”
• We’ve been able to learn more about odontocetes hearing because they are small and easier to keep in captivity.

Mysticetes:

• Minke whales are the smallest mysticete at 4 meters.
• Blue whales are the largest mysticete, up to 25 meters.
• Mysticetes graze on krill, plankton, and small fishes. They use low-frequency sound to communicate and navigate over long distances.
• Mysticetes are too large to hold in captivity so what we do know about them are from wild, open ocean interactions.

Examples:

Odontocetes (toothed whales):

• Dolphin
• Orca “killer whale” (actually in the dolphin family)
• Sperm whale

Mysticetes:

• Minke whale
• Blue whale
• Bowhead whale
• Right whale

Terms:

Cetaceans – whales
Odontocetes – toothed whales
Mysticetes – mustache whales
Low frequency (.1 Hz – 1kHz)
Mid Frequency (1kHz – 10kHz)
High frequency (10kHz – 200kHz)
Echolocation – sensing surroundings by emitting sound and hearing the reflection; also called “Bio-sonar”
Operant conditioning testing – training a subject to respond to a stimulus by reward or punishment; amplifies the response to the stimulus by correlating it to the subject either seeking the reward or expecting punishment when they sense the stimulus