Toni ChristopherMarine MammalsDr. Jerry Skinner

The study of animal sounds, their meanings, and their purpose

Two categories of them Terrestrial or airborne Underwater or Marine

Three sub-categories Hearing ability and mechanisms Sounds and how they’re made Function and meaning of specific sounds

AIRBORNE UNDERWATER

Medium: air

Shorter range sounds

Higher frequency

Medium: water Longer range sounds Lower frequency Sounds heard faster

and clearer Water conducts sounds

better Already matches

density of inner ear where sound is processed

Other senses are dulled by the water

Water absorbs and reflects light, making sight very limited

Smell can’t be relied upon because molecules take so long to diffuse in water

Long, low frequency songs

A single high frequency click or whistle

Rapid bursts of high frequency clicks or whistles

Echolocation, or locating by means of reflected sonar signals Not observed in baleen whales

Communication within the group Navigation Detection of both predators and prey Courtship rituals

Air passes through structure in nasal cavity called phonic lips

Membranes collide and vibrate surrounding tissue

Vibrations pass through head tissue while air enters vestibular sac

Air either reused or sent through blowhole All toothed whales except Sperm Whale

have two sets of phonic lips; one set per independent sound

Thank you Dr. Skinner!

Do not have phonic lips

Larynx may be used but no vocal cords

Don’t need to exhale to produce sounds

Recycled air or cranial sinuses may be used

Base units (“notes”) – single sounds up to a few seconds long May change pitch to higher or lower and/or

amplitude to louder or quieter Sub-phrases – four or six units, ten seconds

at most Phrases – two sub-phrases Themes – phrases repeated over for two to

four minutes Songs – group of themes about 30 min

long Repeated for either hours or days

Defining territory to other whales Sexual selection during mating season Multiple males competing over same

mate “flirting”

Singing reported in groups of one female and many males

Also reported when a male is following a female around, acting as an “escort”

Echolocation

Toni ChristopherMarine MammalsDr. Jerry Skinner