Lecture 17 - Migration

Question 1

What is animal migration

Answer 1

The temporary movement of Individuals or populations (or parts of populations) between two well-defined habitats with a return journey

This movement may occur on a temporally predictable basis (day, season, lifetime)

Question 2

Dispersal

Answer 2

Unidirectional movement of animals or cells for a specific purpose (expansion of habitat/wound healing)

Question 3

The transpolar migration of the artic

Answer 3

Green = during autumn (post-breeding) migration (August–November) down south (Antarctica)

Red = winter range (December–March) migration west across Antarctica

Yellow = spring (return) migration (April–May) up back north towards greenland

Question 4

Transoceanic migration of sharks

Answer 4

Great white sharks travel between northern Australia and South Africa (11,000km)

Question 5

Anadromy

Answer 5

Where a fish is born in freshwater, matures in salt water (ocean/sea), and returns back to freshwater to reproduce

Question 6

Catadromy

Answer 6

Where a fish is born in salt water (ocean/sea), matures in freshwater, and returns back to salt water to reproduce

Question 7

The most common form of migration in the animal kingdom

Answer 7

Part of the population migrates and part stays resident

Question 8

Diel vertical migration

Answer 8

The synchronised movement of zooplankton and fish up and down in the water column over a daily cycle

Question 9

Costs of migration

Answer 9

Increased predation, the energetic cost of movement, more pathogens and parasites, and the uncertainty of the final destination

Question 10

Benefits of migration

Answer 10

Enhanced foraging possibilities, avoiding current predators, extreme climate avoidance, and potential reproductive success

Question 11

Migration difficulties due to human interference

Answer 11

Humans cause habitat loss and degradation, causing lower habitat connectivity (migratory corridors) and so stop points for migratory animals may be ruined

This is why migratory animals are so sensitive to habitat change

Question 12

Elsie lake dam

Answer 12

Led to local extinction of anadromous Pacific lamprey

Question 13

Xiananjiang dam

Answer 13

Riverine species loss of fishes from 107 to 83 due to disruption to migratory journeys

Question 14

Types of migration

Answer 14

Transgenerational, partial, diel vertical, anadromous, and catadromous