Chap 12 Flashcards
(26 cards)
critically endangered
the species has an extremely high risk of going extinct in the wild
extinct
the species is no longer known to exist
extinct in the wild
the species exists only in cultivation, in captivity, or as a naturalized population well outside its original range
For species you need to know
the number of individuals of endangered spp there are out there,
What threats they are facing
IUCN broken into 5 categories
- Extinct, Extinct in wild
- Critically endangered, endangered, vulnerable
- Near threatened, Least concern
- Data deficient
- Not evaluated
endangered
the species has a very high risk of extinction in the wild
vulnerable
the species has a high risk of extinction in the wild
Near threatened
the species is close to qualifying for a threatened category, but is not currently considered threatened
Least concern
the species is not considered near threatened or threatened
data deficient
inadequate information exists to determine the risk of extinction
Not evaluated
the species has not yet been evaluated against the Red List criteria
most spp are not evaluated
IUCN red list criteria for assignment to critically endangered category
A. Observed reduction in numbers of individuals
B. Total geographic area occupied by the species
C. predicated decline in number of individuals
D. Number of mature individuals currently alive
E. Probability the species will go extinct within a certain number of years or generations
A. Observed reduction in numbers of individuals
the population has declined by ≥80% over the last 10 years or 3 generations, based either on direct observations or inferred from factors such as levels of exploitation, threats from introduced species and disease, or habitat destruction and.or degradation
B. Total geographic area occupied by the species
the species has a restricted range (<100km2 at a single location) and there is observed or predicated habitat loss, fragmentation, ecological imbalance, or heavy commercial exploitation
C. predicated decline in number of individuals
the total population size is <250 mature, breeding individuals and is expected to decline by ≥25% within 3 years or 1 generation
D. Number of mature individuals currently alive
the population size is < 50 mature individuals
E. Probability the species will go extinct within a certain number of years or generations
extinction probability is >50% within 10 years or 3 generations
The IUCN categorizes the top 10 causes for species listed as critically endangered, endangered, and vulnerable
Lowest to highest
- Persecution
- Accidental mortality
- Changed native species dynamics
- Natural disasters
- Human disturbance
- Invasive species
- Pollution
- Harvesting
- Intrinsic factors
- Habitat loss/degradation
Threat analysis
an assessment of the factors that caused the population to decline and that are keeping the population at dangerously low numbers
The IUCN threats are….
general categories that are determined largely through expert opinion
detailed, ________ needs to be performed before conservation plans and action can be made
species-specific analysis
To assess threats, conservation scientists rely on 3 principle methods:
- manipulative experiments
- observational studies
- models
Manipulative experiments
treatments are assigned to study subjects
Manipulative experiments, 3 key elements
- must control for confounding variables
- must have replication
- must have randomly assigned treatments
