Topic 26 -Conservation: Extinction

Question 1

examples of extinction due to human activities

Answer 1

dodo, passenger pigeon, stellar’s sea cow, Sumatran rhino

Question 2

what are the three types of extinction

Answer 2

Background Extinction
Mass Extinction
Anthropogenic Extinction

Question 3

Background extinction

Answer 3

species disappear and others take their place as environmental conditions change

Question 4

Mass Extinction

Answer 4

dying off large numbers of species as a result of natural catastrophes

Question 5

Anthropogenic mass extinction

Answer 5

dying off of large number of species as a result of human activities

Question 6

what have fossils told us about the background rate of extinction

Answer 6

1 species/year

Question 7

present anthropogenic extinction is ______times the background rate

Answer 7

1000

Question 8

Extinction is defined

Answer 8

disappearance of all individuals of a species (elimination of a species)

Question 9

Extirpation

Answer 9

the disappearance of a population of a particular species from a local area (elimination of a population)

a population may be extirpated but the species is not extinct

Question 10

what are the 6 types of extinction risks

Answer 10

smaller populations have a greater risk of extinction than larger ones

The larger the geographical range of a species- the lower the risk of extinction

the more age structure of a species -the lower risk of extinction

Large, endothermic animals have a lower risk than smaller endothermic animals

ectothermic animals have a greater risk than endothermic animals

k-selected species have a lower population resilience and so an increased risk of extinction

Question 11

allee effect

Answer 11

with species that derive benefits from naturally aggregating (ie. safety from predators) smaller population sizes can further decrease chance of success

Question 12

extinction vortex

Answer 12

a cyclic chain of events that result in a small population continuing to get smaller as a result of being small

Question 13

ubiquitors

Answer 13

widespread over a large area

Question 14

endemic

Answer 14

only occur in small areas

loss of habitat in one area leads to loss of species

Question 15

Conservation Biology

Answer 15

an integrative discipline that applies the principles of ecology to the protection of biodiversity

actual scientific discipline only since 1980

international union for the conservation of nature and natural resources

Question 16

Red list of threatened species

Answer 16

more than 26 000 species at risk of extinction
roughly 1% of species world wide
based off of 5% of described species (VERY LIKELY AN UNDERESTIMATE)

Question 17

Advantage of the IUCN classification system

Answer 17

provides a standard, quantifiable method of classifying species

Question 18

what is the problem with the classification system, what do they do to prevent this?

Answer 18

often do not have complete information

precautionary principle -in the absence of complete scientific date, uncertainty will not be used as a reason to postpone conservation efforts of species when the species is faced with the threat of serious or irreversible harm

Question 19

what are the three levels for the IUCN classification system

Answer 19

Critically endangered: have a 50% chance of extinction within 10 years (or 3 generations), whichever is longer

Endangered: have a 20% chance within 20years (or 5 generation)

Vulnerable: have a 10% chance of extinction within 100 years

Question 20

three different conservation strategies

Answer 20

Ex-situ rehabilitation
Genetic recombination
Habitat management

Question 21

Ex-situ rehabilitation

Answer 21

raise populations of species in captivity when they become “extinct in the wild” preparing for reintroduction ex california condor

Question 22

Genetic recombination

Answer 22

mix remnant populations with wild populations of related species with which breeding may occur naturally to preserve genes ex florida panthers

Question 23

Habitat management

Answer 23

preserve the natural habitat of the threatened species and hope it can restore its population sizes naturally ex prairie chicken

Question 24

Biodiversity hotspot approach

Answer 24

myers et al. 2000 Nature identified concentrated areas of high species richness “hotspots”

primary based on plant species (reflect insects)
secondary based on vertebrates

Question 25

myers defined hotspots based on 2 criteria

Answer 25

exceptional concentration of endemic (rare) species
used endemism because of low scientific info on number of species

exceptional loss of habitat -endemic species are highly vulnerable to habitat loss (extirpation can mean extinction)

cost effective way of conserving the largest number of species -with the littlest scientific information