Selected Habitats: Oceanic Islands

Question 1

What is an oceanic island?

Answer 1

Islands that are sufficiently isolated from major land masses so it is difficult for species to colonise

Question 2

How were most oceanic islands formed?

Answer 2

Volcanic eruptions or the build-up of sand from nearby corals

Question 3

What species are most likely colonise oceanic islands easily?

Answer 3

Marine species
Sea birds
Plants with floating seeds

Question 4

What species colonise oceanic islands by chance?

Answer 4

Tortoises

Terrestrial birds

Question 5

How can tortoises end up on oceanic islands?

Answer 5

By being carried on drifting logs

Question 6

How can terrestrial birds end up on oceanic islands?

Answer 6

If they are carried by strong winds

Question 7

What will happen to species that colonise the oceanic islands?

Answer 7

They will gradually evolve to occupy the available ecological niches

Question 8

How does evolution create unique species?

Answer 8

As the conditions that affect selection pressure, and the characteristics that provide a survival advantage are different in different places

Question 9

Why might biodiversity by low on oceanic islands?

Answer 9

Because they are difficult to colonise

One or more groups of organisms may not be present

Question 10

Why aren’t many mammals found on oceanic islands?

Answer 10

Its hard for them to colonise isolated islands

Question 11

What sort of mamamals will colonise oceanic islands?

Answer 11

Seals and bats but not terrestrial mammals

Question 12

What sort of islands will have mammal species?

Answer 12

Those that were previously attached to continents

Question 13

What is an example of where mammals are present on oceanic islands after disconnecting from continents?

Answer 13

Lemurs in Madagascar

Question 14

Why are oceanic islands important?

Answer 14

The high proportion of endemic species increases the possibility of the discovery of unique medicines or features for biomemetics

Question 15

How were species exploited on oceanic islands?

Answer 15

Species were heavily exploited for food

Question 16

What species found on oceanic islands have been exploited for food?

Answer 16

Dodo
Giant tortoises
Marine turtles

Question 17

How can introduced predator species affect oceanic islands?

Answer 17

Due to the lack of mammal predators the indigenous species are not adapted to survive predatory species

Question 18

What are some examples of predatory species on oceanic islands?

Answer 18

Rats form shipwrecks

Cats that were introduced as pets

Question 19

What is the problem with introduced herbivores?

Answer 19

They destroy the indigenous plant communities

Question 20

What are some examples of introduced herbivores on oceanic islands?

Answer 20

Goats

Rabbits

Question 21

What are the problems with introduced plants on oceanic islands?

Answer 21

They may outcompete the indigenous vegetation

Question 22

what is an example of how an oceanic island was affected by an introduced pathogen?

Answer 22

Avian malaria was introduced Hawaii which killed many bird species

Question 23

How will climate change affect the spread on Avian malaria?

Answer 23

Usually not present above 1500m due to the cold but with rising temperatures it may be able to spread to higher altitudes

Question 24

What causes habitat destruction on oceanic islands?

Answer 24

Urban, agricultural and tourist developments

Question 25

How do the oceans threaten oceanic islands?

Answer 25

Sea level rise

Question 26

How can oceanic islands be conserved?

Answer 26

Usually by attempts to stop or reverse the damaging effects of human action

Question 27

What has been the biggest single action to conserve endemic species on oceanic islands?

Answer 27

The eradication of introduced species

Rats, goats, cats and rabbits

Question 28

How many islands have introduced species successfully been eradicated from?

Answer 28

Nearly 1000