L4 - Prioritisation

Question 1

What is the ideal preservation method?

Answer 1

To preserve every cog and wheel in an ecosystem - but there are too many species to give them equal attention

Question 2

What are the four main approaches to prioritisation?

Answer 2

1) Taxonomically unique species
2) Species that indirectly protect others (keystone / umbrella / flagship / indicator)
3) Rare species
4) Threatened species

Question 3

What does it mean to be taxonomically distinct?

Answer 3

The degree to which a species or a group of species differs from others in its evolutionary relationship, rather than just its physical characteristics or shared common names

Question 4

Why are taxonomically unique species important to conserve?

Answer 4

They have great genetic diversity - sole family representatives have greater conservation importance as they represent more genetic and functional diversity.

Question 5

How many genera have gone extinct since 1500?

Answer 5

75 gone extinct, and the extinction rate is 35x higher than background extinction rate.

Question 6

What is the Vane-Wright equation for distinctiveness?

Answer 6

D = (Max branches from root) / (Branches from root to spp)

Question 7

What are the pros and cons of prioritising taxonomically unique species?

Answer 7

PROS - based on sound and intuitive principal

CONS - requires detailed taxonomic knowledge, only works for some groups

Question 8

What is a Keystone Species?

Answer 8

A species whose impact on its community or ecosystem is large, and disproportionately large relative to its biomass

Question 9

Give an example of a keystone species?

Answer 9

Eg. Starfish
- When removed from an ecosystem, the original system collapsed from 15 to 8 species
- starfish are predators that prevent other species dominating

Question 10

What is the equation for the Community Importance index (CI)?

Answer 10

CI = (change in community trait) / (change in focal spp biomass)

A CI > 1 indicates a keystone species

Question 11

What are the negatives of keystone preservation?

Answer 11

1) Many keystone species are only identified from anecdotal evidence
2) Robust identification of keystone species is difficult, often requires removal experiments
3) A few now-keystone species can have equivalent effects of a keystone

Question 12

What is an umbrella species?

Answer 12

A species, usually large vertebrates, that requires a large area for its conservation. Protection of an umbrella species encompasses other species with similar habitat requirements.

Question 13

What is an example of an umbrella species?

Answer 13

Saiga antelope -
- in 1950 had 2 million, 2010 saw a 95% decline = critically endangered

Question 14

What is a flagship species?

Answer 14

A charismatic species that promotes conservation of a region / habitat. Can require small or large areas - eg. seahorse (home range 10m2) and panda (4-8km2)

Question 15

What is an indicator species?

Answer 15

A species with a narrow ecological tolerance so reliably only found in a specific habitat

Question 16

What is a rare species?

Answer 16

• Small geographic range size
• Small population size
• Habitat specialist

Question 17

Are rare species always threatened?

Answer 17

Short answer = no
Eg. Seychelles Small Day Gecko
- endemic and very small geographic range - c. 50,000 individuals
- But found in high population densities, natural habitat rainforest but can survive in agricultural and urban areas

Question 18

Give two examples of common species going extinct

Answer 18

1) Rocky mountain Grasshopper
- 1880s were very abundant
- by 1902 went extinct - probably due to a loss of breeding habitat

2) Passenger pigeon
- 25-40% of North American birds
- 3-5 bill. discovered when Europeans discovered US
- Extinct by 1914 - due to habitat loss and hunting

Question 19

How are species prioritised by extinction threat?

Answer 19

Population Viability Analysis (PVA) is based on detailed demographic data:
- current pop size
- birth rate
- date rate
- how these vary with the environment

Question 20

What is the IUCN red list?

Answer 20

• Process started in the 1960s
• c. 170,000 species now assessed
• All birds, mammals, amphibians and corals
• plans underway for plants and fish

Question 21

What are the four levels of endangerment?

Answer 21

Critically endangered
Endangered
Vulnerable
Near Threatened

Question 22

What are the 6 criteria the IUCN evaluations are based on?

Answer 22

1) Range size
2) Population size
3) Number of populations
4) Severely fragmented populations
5) Population trend
6) Extreme population fluctuations

Question 23

What are the two definitions for range size?

Answer 23

1) Extent of occurrence - area within the range boundary
2) Area of Occupancy (AoO) - occupied grid cells within boundary

Question 24

How is the population size determined?

Answer 24

- Based of the number of mature individuals capable of reproduction - Re-introduced individuals must have bred successfully before being counted - If sex ratios or breeding ratios biased, tries to take this into account

Question 25

What are