Feeding Stratgies:

Question 1

What is the diet of odontocetes?

Answer 1

Fish: Oceanic dolphins
Squid: Sperm whales, beaked, pilot, Risso’s dolphins

Question 2

How does feeding in odontocetes contrast to that in mysticetes?

Answer 2

Hunt individual prey items
Several species target deep prey
Less seasonal diets
- Many follow diel feeding patterns where they follow the vertical migration of the deep scattering layer

Question 3

What is the deep scattering layer?

Answer 3

Deep water with a diurnal vertical migration
Largest animal migration in terms of biomass
Small mesopelagic fish, crustaceans, squid

Question 4

How are orca’s extreme specialists when it comes to foraging and diet?

Answer 4

Residents orca whales: salmon eaters
Transient orca whales: marine mammal eaters

Question 5

How are bottlenose dolphins extreme generalists when it comes to foraging and diet?

Answer 5

Will eat any fish or squid nearby of right size
Use a variety of techniques

Question 6

What does specialisation or differences in diet in odontocetes influence?

Answer 6

Behaviour, habitat use, and physiology

Question 7

What is the feeding ecology of mysticetes?

Answer 7

Lunge feeders (rorqual) - smaller baleen
Skim feeders (right whales) - large baleen
Suction feeders (grey whales)

Question 8

What food do mysticetes target?

Answer 8

Lunge feeders: krill, small fish
Skim feeders: copepods
Suction feeders: benthic crustaceans

Question 9

What are the mechanics of lunge feeding?

Answer 9

Whales accelerate rapidly towards a dense aggregation of prey. They then open their mouths to an 80’ angle which fulls up with water. They then invert their tongue and inflate their buccal cavity. The drag created brings them to a near stop. They close their mouths and filter the water through their baleen (at a slow swim or glide). Once the water has been excreted, the whale accelerates

Question 10

What are the Energetics of lunge feeding?

Answer 10

High energy feeding on tiny prey is enough to sustain them as the energetic cost of a single lunge is much less then that gained from the krill.

Question 11

What is bubble-netting in humpback whales?

Answer 11

Cooperative behaviour where they produce bubbles to concentrate small fish towards the surface before engulfing them.