BIOL 3626: Day 2

Water Properties

• dense, viscous

• transmits light and chemical signals poorly

  • however, sound travels well

• 0.5-0.9% O₂ at surface

Cetacean Traits

• warm blooded, and high metabolic rate

  • allows cetaceans to swim fast for long periods and maintain large brains

  • however, they cannot be small, need a lot of insulation (via fur or blubber), and must eat a lot

• obtain oxygen by breathing

  • allows inhabitation of waters with low oxygen content, and may even be able to go onto land

  • however, this means they must be able to go onto land

• internal reproduction and lactation

  • mother can protect and care for young when small, and form a prolonged mother-young relationship

  • however, this leads to lower reproductive rates

Mysticete vs. Odontocete Reproductive Investment

• generally, odontocetes spend much more time with their young than mysticetes

Compared to other ocean inhabitants, cetaceans are generally

• near the surface

• voracious

• covered in blubber

• large

• acoustic

• K-selected species

• good mothers but poor fathers

• social

• cognitively advanced

• very vulnerable to human harvesting

Mysticetes

• Baleen whales

• 14 species

• 6-32 metres long

  • largest: blue

• very seasonal, with very long migrations

• thick blubber

• typical reproductive rate:

  • 2 year inter-birth interval

• 20-200 yr longevity

  • longest lived: bowhead

Odontocetes

• sonar abilities

• 75 species

• 1.5-17m long

  • sperm whale largest

• nomadic or sedentary

• thinner blubber

• variable reproductive rate:

  • 1-5 years

• 8-100 yr longevity

Spectogram

• makes sound visible

  • the louder it is, the brighter it appears

Echolocation

• melon serves as a sac of fatty liquid which they ‘shoot’ a sound wave out of

  • to be recieved back, unlike bats, odontocetes do not have ears. rather, they have fused their ear bones to their jaw

• this is modified in sperm whales

Sperm Whale Echolocation

• differs from other odontocetes

• 2 melons present, the junk and the spermaceti organ. phonic lips in between both melons produces sound which hits the skull (click gets amplified), which gets shot out through the mouth

  • this click can be used to calculate the size of the whale !

Deepest/longest diving cetaceans

• Cuvier’s Beaked Whale can dive the deepest

  • can dive up to 2,992m !

• Sperm Whales can dive for the longest

  • can dive up to 2 hours !

Diving Adaptation

• blood rich in hemoglobin, muscles rich in myoglobin

  • much more effective at storing oxygen

• ability to slow heartbeat down drastically (up to as low as 2 beats per minute)

Blubber

• works to insulate, and thermoregulate the body

  • if the animal is too hot, the blood can be brought out to extremities to cool down blood, then to return back to body

• 3 main functions

  • insulation

  • energy

  • buoyancy

• mother whales can have their blubber be ‘built up’ so that they can create energy reserves to provide milk for calves

Blubber Composition

• skin

• outer later

• transitional layer

• middle layer

• transitional layer

• inner layer

• muscle

Vestigial Bone

• whale’s tail adapted from their tail bone, rather than their legs. because of this, the vestigial pelvis bone remains. however, there is no purpose for it

Swimming Musculature

• massive muscles where pointed to

  • same muscles which are used when humans do a “butterfly” swimming pattern

Asphyxiation

• since a blowhole is a nose, if something gets into it, the cetacean can asphyxiate/choke

Osmoregulation

• regulation of sodium/electrolyte levels within the body

  • since it is harmful to drink salt water, they get most of their water sources from their food

• CRUCIAL: whales don’t drink salt water !

3 Tiers of Social Structures

• Matrilines

  • tight knight family groups dependent on the mother/grandmother

• Individuals

  • social group, but not connected dependent on family

• Alliances

  • fission fusion groups

Maritime Matriline Species

• pilot whales

• orcas

• sperm whales

Fission Fusion Maritime Species

• atlantic white sided dolphins

• white beaked

PAM

• P___ Acoustic Monitoring

Why use PAM

• mitigation

• research

• characterizing species signals

• sound source characterization

• distribution and movements

• validating models

• assessing impacts

How is PAM data collected?

• hydrophone dipping

• towed array

  • chain of multiple hydrophones from a moving platform

• bottom mounted recorders

  • stationary, long term, data accessible once equipment received

• autonomous platforms

EXAM SHORT ANSWER: Whats the coolest thing you learned from “How to be a whale”?

• description of the move to water from land 50 million years ago

  • loss of hair (save a few whiskers)

  • nostrils move to the top of head

  • loss of legs

• blue whale:

  • heart rate can descend down to 2 beats per minute

  • voice can travel 500 miles

    • loudest voice of all animals

    • voice too deep for the human register

• fin whales

  • voice so powerful it can penetrate to the earths crust

• dialects and fashions of orcas; social tradition

• the ___ has an essential call, unique to all others

• 200 L whale excrement starts micro environments

  • once the southern ocean was depleted of whales during the whaling epidemic, massive ecosystem collapse followed because of the lack of ‘whale pumps’

• whale falls; carbon sink, bring nutrients down, etc.

• 52 blue; interbreeding of blue and fin whales

  • how do they breed if the two species cant communicate with eachother ?

• coolest thing for the instructor: we dont know what these calls mean !! we know for some how they are made, but for most we dont even know this

Echolocation

• used to hunt, orient themselves, understand everything that is around them

• monkey lips creates a sound, shoots to the frontal air sac, which is sent out through the mouth (passes both the spermaceti organ and the junk, both 2 versions of a melon)

  • once the sound is hit back and returned, it is recieved via jaw bone and sent to the ‘ear’

Socialization

• echolocation may be used to communicate with other individuals via multi level social structure

  • comprised of units, groups, and clans

Culture

• vertical culture: a parent teaches a younger generation

• horizontal culture: jules picks up on janis joplins accent

Coda

• series of 2-15 clicks with a ‘marble’ sound

• used to differentiate whether or not a separate clan of sperm whales ‘speaks their coda/language’

  • similar to morse code, in that they are comprised of a series of ‘dots’