Protected Species Flashcards
How does rarity influence extinction risk (Darwin)
“Rarity is the precursor to extinction… any form represented by few individuals will, during fluctuations in the seasons or in the number of its enemies, run a good chance of utter extinction.”
Describe what many species have evolved
Narrow distributions – endemics, found nowhere else in the world
Low population densities
Specialised habitat requirements
Extinction risk increases when populations / distributions decline due to external factors (threats)
Describe the extinct category
No reasonable doubt that the last individual has died after systematic exhaustive surveys
Describe the extinct in the wild category
Only survives in cultivation, captivity or naturalised populations outside past range
Describe the red list category criteria by Mace and Lande
Propose Red List categories based on quantitative assessment of extinction probability using viability analysis (PVA).
Innovations:
a) % risk of extinction over time scale
b) flexible data requirements
Describe the raw data to red list process
Majority of assessments carried out by
- members ofIUCN Species Survival Commission(SSC) appointRed List Authorities(RLAs)
- Red List Partners, or specialists working on IUCN-led projects
- But assessments can be carried out by anyone who has sufficient knowledge of a species and submitted to IUCN
Describe threatened species
> 10% extinction risk in 100 years
Describe the red list category criteria for the critically endangered (A)
A 1. Observed, estimated, inferred or suspected > 90% population reduction over last 10 years or three generations (whichever is longer) when causes ARE reversible AND understood AND ceased
A 2. OBSERVED… > 80% reduction, may NOT be reversible OR NOT understood OR NOT have ceased
A 3. > 80% PROJECTED population reduction over PAST 10 years / 3 generations
A 4. > 80% PROJECTED population reduction over 10 years / 3 generations – TIME PERIOD INCLUDES PAST AND FUTURE
Describe the red list category criteria for the critically endangered (B)
B. 1 & 2 – GEOGRAPHICAL RANGE <100km2 AND two of a-c:
a. Fragmented or isolated
b. Continued decline in numbers or habitat
c. Extreme fluctuations in population/area
Describe the red list category criteria for the critically endangered (C and D and E)
C. POPULATION SIZE – less than 250 mature individuals and declining
D. < 50 mature individuals
E. PROBABILITY OF EXTINCTION 50% over 10 years/3 generations (up to max of 100 years
Describe the red list category criteria for endangered species
A. > 70% and 50%
B. <5000km2 AND DECLINE
C. 2,500 mature individuals and decline
D. 250 mature individuals
E. 20% prob. of extinction in 20 years
Describe the red list category criteria for vulnerable species
A > 50% and 30%
B <20,000km2 AND DECLINE
C. 10,000 mature individuals and decline
D. 1000 mature individuals or <20 km2
E. 10% in 100 years
Describe near threatened species
Close to qualifying for a threatened category and likely to qualify in the future
Describe least concern species
Has been evaluated and does not qualify for threatened or near threatened species
Has been evaluated and does not qualify for threatened or near threatened
Describe data deficient
- Taxon is Data Deficient when inadequate information to make a direct, or indirect, assessment of its risk of extinction based on its distribution and/or population status.
- May be well studied, biology well known, but data on abundance and/or distribution are lacking.
- More information is required and acknowledges the possibility that future research will show that threatened classification is appropriate.
