Locomotion/energetics

Appendicular skeleton

• pectoral limb complex ( forelimb)

• pelvic limb complex (hindlimb)

Energetics

• population successes and population decline

• reproduction

• direct link between behavior and energetics

Pectoral limb complex

• widen scapula

• more marine adapted → shorter the forelimb will be

• whales have a shorter forelimb than seals

Flipper shape: wide/flatter

• fast and agile

• sharper you can turn → creates drag

• good hunters

  • killer whales, right whales, sperm whales, humpback whales

    • novels in the flippers allow them to cut through drag

• flat and paddle like: maneuverability

Flipper shape: streamlined flippers

• moving fast in one direction

  • dolphins, risso’s dolphin, Sei whale, pilot whale

• pointy and slender: fast

Pelvic limb complex

• streamlining

• where the energy is coming from is going to be different

• fluking orientation or side to side orientation

Cetacean Tail (fluke)

• no muscles and no bone

Cetacean Dorsal fin

• prevent organism from rolling

• drag

• cut through water in order to breathe better

  • more energetically

• right whale dolphins do not have a dorsal fin

• Falcate: white-sided dolphin

• Elongate: killer whale

• Triangular: Irrawaddy dolphin

• rounded: hector’s dolphin

Terrestrial locomotion: otariidae

• big feet but small amount of separation

• cannot walk left, right

  • swing legs, and shuffle back and forth

• not energetically efficient

Terrestrial locomotion: Phocidae

• can not put any weight on back flippers

  • need to bounce on their stomachs to move on land

    • more marine adapted

Terrestrial locomotion: Odobenidae

• left right lumbering

• have to go flipper first

• have to be careful no to trample each other

  • habitat loss → less space

streamlined bodies

• dealing with the density of water has big energetic costs

• being more streamlined = less energetic costs

Swimming mechanics: Polar bear

• forelimb” crawl”

Swimming mechanics: sea otter

• pelvic paddle

Swimming mechanics: eared seals

• fore flipper locomotion

Swimming mechanics: true seals

• lateral= side to side

• thunniform ( swim like a tuna)

Swimming mechanics: cetaceans and sirenians

• Dorso- ventral= up- down

Morphology propulsion

• increased are over evolutionary time

  • inter digital webbing, to fins, to large flukes

Energetics: fasting

• migration

  • humpback whales

• reproduction

  • pinnipeds

• molt

  • elephant seals (true seals)

  • weddel seals

Energetics: feast or famine

• cold water supports life better

  • gray whales in near Alaska

  • better productivity of plankton and nutrients as they move north

• gain food at higher latitudes

• lose at low latitudes

  • birthing and breeding season December- April in warmer waters

Energetics and body size

• larger animals have lower relative locomotion costs

Ecological drivers: manatees

• have very low resting metabolic rate

• slow grazing, warm ocean temps, move very slow

Ecological drivers: sea otters

• very high resting metabolic rate

• eat a lot of food → provide warmth, live in cold water

Cost of transportation: body size

• being semi aquatic is more energetically costly

• whales can migrate because they can go months without earting

  • driven by ecology of the ocean

  • driven by body size

  • driven by the need to breed