Slide Set 11

Question 1

what are the 4 island types?

Answer 1

• continental
• island acres
• hotspot islands
• terrains and accretion

Question 2

where did continental islands originate?

Answer 2

• part of continental landmass

- formed by rising ocean levels and separated by tectonic processes

Question 3

describe the origin of island acres

Answer 3

• volcanic activity
• old ocean rust subducted causing stresses nearby on the overlying plate; volcanic eruptions build new islands that rise above the seafloor

Question 4

describe origin of hotspot islands and seamounts

Answer 4

• fixed hotspots scattered throughout the earths mantle
• volcanoes rise from the seafloor, plates move and islands born
• erosion reduces islands seamounts

Question 5

describe formation of island chain

Answer 5

• erosion flattens the top of islands and seamounts

- seamounts are islands of biodivercity

Question 6

seamounts

Answer 6

islands of incredible biodiversity, poorly known and being destroyed rapidly

Question 7

what is the bend in the emperor seamount

Answer 7

Hawaiian island chain suggested to be caused by a change in direction of the movement of the pacific plate about 43mya

Question 8

what are the 3 pacific islands

Answer 8

1. continental (new zealand, new caledonia)
2. island arc ( the aleutians, the kuriles)
3. hotspot islands (tuamato ridge, hawaiia islands, archipelago)

Question 9

describe terrain

Answer 9

a small area where geology is different from surrounding regions

Question 10

describe accreted terrane

Answer 10

landmass that originated as an island arc or micro continent that was later added onto a continent or other landmass

Question 11

describe archipelagos

Answer 11

variation in size and degree of isolation among islands

Question 12

what is the equilibrium theory of island biogeography

Answer 12

role of rates of immigration and extinction in controlling species divercity

Question 13

islands usually have ________ species than comparable mainland areas

Answer 13

fewer

Question 14

often the relative ____________ of species on islands is not the same as in comparable areas on the mainland

Answer 14

density

Question 15

often island densities are _________ than those con specifics on the mainlands

Answer 15

higher

Question 16

what are the patterns in island species composition

Answer 16

harmonic and disharmonic

Question 17

Harmonic biotas

Answer 17

balanced species composition similar to mainland

- expected if species are assembled randomly from mainland source pools

Question 18

dis harmonic biotas

Answer 18

unbalanced species composition is different from mainland composition
- expected if non random processes are important

Question 19

active dispersal

Answer 19

flight, ability to cope with seawater

- bats and birds and insects

Question 20

passive dispersal

Answer 20

high altitude winds, high velocity winds, ocean currents, hitch hiking
- via spores, fungi, seeds, fruits, egg masses, insects and some vertebrates

Question 21

many island species are _________ rather than specialists

Answer 21

generalists

Question 22

why are island species generalists

Answer 22

• role of resource limitations compared to mainland areas, food resources have lower standing stocks and renewal rates
• organisms that have lower demands are less fussy and have a greater probability of establishing a persisting population

Question 23

island food resources are _________

Answer 23

limited

Question 24

what are advantages of being a small bodied generalist

Answer 24

• small animals need less
• different sources
• small animals can maintain higher max pop densities
• such populations are less susceptible to extinction through demographic processes

Question 25

in general the greater the area the _____ the number of species supported

Answer 25

greater

Question 26

is island species relationship linear?

Answer 26

no, richeness increases less rapidly for larger islands | S=cA^(z)

Question 27

smaller islands have greater rates of __________

Answer 27

extinction

Question 28

density overcompensation on small islands is common because?

Answer 28

large vertebrates and predators are absent, absence of cogners (other members of feeding guild), reduced competition, high densities of insects and food resources, surrounding water prevent emigration and immigration

Question 29

what is the island rule for body size?

Answer 29

tendency for small animals to become bigger and for big animals to become smaller, seems to apply for most mammals and some birds,snakes and turtles and some marine creatures

Question 30

dwarfism

Answer 30

big animals become smaller

Question 31

gigantism

Answer 31

normally small animals become bigger, trend seen in herbivores and seed eaters

Question 32

for small animals what are the 3 factors that promote gigantism?

Answer 32

1. immigration selection 2. intensified transpacific competition 3. ecological release from large competitors and predators

Question 33

for large animals what are the 3 factors that promote dwarfism?

Answer 33

1. ecological release from predators 2. intensified intraspecific competition 3. resource limitation and specialization for insular niches

Question 34

what is diamonds study of non marine resident birds?

Answer 34

only islands close to source have close to the expected number of bird species - greater the distance from source pool the more depaurate the avifauna

Question 35

as distance increases non volant mammal species richness _________ fro islands in the st lawrence

Answer 35

decreases

Question 36

islands in the central and eastern pacific have ______ gnerea

Answer 36

fewer

Question 37

islands are ________ of species from a source pool of species living on mainland area

Answer 37

recipients

Question 38

the number of species received by an island depends on what 3 things?

Answer 38

1. island size 2. Island distance 3. the source pool of species and their characteristics (richness and vagility)

Question 39

islands that are far away have _____ rates of immigration than islands that are closer to source pools of species

Answer 39

lower

Question 40

larger islands would have _____ rates of extinction, while smaller islands would have ________rates of extinction

Answer 40

lower, higher

Question 41

if there is plants present is it ____likely for there to be animals present

Answer 41

more

Question 42

MacArthur and Wilson stated

Answer 42

distance or isolation affects the rate of immigration, and size affects the rate of extinction *these control at equilibrium the number of species and the rate at which species turn over

Question 43

two equal sized islands that differ in distance from the source pool have the same __________rates but different _________ rates

Answer 43

extinction, immigration

Question 44

two different sized islands would have the same rate of __________ but different rates of ___________ where they would be greater on the smaller island

Answer 44

immigration, extinction

Question 45

immigration and extinction are ________ processes

Answer 45

independent