Toni Christopher Marine Mammals Dr. Jerry Skinner
Dec 23, 2015
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