Extinction - What makes a species vulnerable to extinction? Flashcards
Define Extinction
- species has completely disappeared
Define Extinction in wild
- species exists ex situ (managed populations in zoos or natural areas where it is not native, cultivated pops)
Define Extirpation
Species exists in wild elsewhere but it is no longer in local area…locally extinct
Define Regional Extinction
Extinct in country or region of interest, but exists it exists elsewhere
Define Ecological Extinction
Species exists in-situ but pops very small -> species has insignificant impact ton its community
Define Endemism
a species that is geographically restricted to a region (when endemic is lost in one area, it is lost globally)
Which are more vulnerable to extinction, common or rare species?
rare
L> term rare can be applied to the entire geographic range of a sp or its distribution and abundance in a specific place
Are all endemic species endangered species?
not necessarily
Define artificially rare
a species that was once widespread but now has a narrow range due to human activity
Define neoendemic
endemic sp that occupy a narrow range bc it recently speciated from a wide spread closely related species (peripheral isolate speciation)
L> naturally quite rare
Define plaeoendemic
endemic species that are the only living descendants of their lineage
L> ex: coelacanths, Giant Panda
*naturally rare
What does biodiversity hotspot mean?
- places with high degree of biodiversity (must contain a specific degree of endemism), threatened with at least 70% habitat loss
What are high-irreplaceability areas?
areas that contain at least one at risk endemic sp are considered irreplaceable, target all areas with at least one endemic sp (different approach to hotspot conservation)
**covers more islands
Who determines which species are at risk?
- IUCN
- International Union for Conservation of Nature (IUCN)
L> influence, encourage and assist societies throughout the world to conserve the integrity and diversity of nature and to ensure that any use of natural resources is equitable and ecologically sustainable
L> publishes a red list: comprehensive info on status of wild species
What conservations services does the IUCN provide?
- conservation planning
L> informs species based conservation actions and identifies important conservations sites - decision making
L> influences conservation decisions at various scales - monitoring
L> indicating the current status of species and revealing trends in their extinction risk over time, to track progress - assesses extinction risk of known species
What are the IUCN Red list categories?
- Extinct (EX)
- Extinct in Wild (EW)
- Critically Endangered (CR)
- Endangered (EN)
- Vulnerable (VU)
- Near Threatened (NT)
- Least Concern (LC)
- Data deficient (DD)
- Not evaluated (NE)
What are two additional IUCN red list categories at the regional/national level?
- Regionally extinct (RE)
2. Not applicable (NA)
Define IUCN Red list categories:
1. Extinction (EX)
- no longer exists anywhere
Define IUCN Red list categories:
2. Extinct in wild (EW)
- only extant in cultivated or captive or naturalized outside of its OG range
Define IUCN Red list categories:
3. Critically Endangered (CR)
- extremely high risk of extinction in wild
Define IUCN Red list categories:
4. Endangered (EN)
- at very high risk of extinction in wild
Define IUCN Red list categories:
5. Vulnerable (VU)
- at risk of extinction in wild
Define IUCN Red list categories:
6. Near Threatened (NT)
-close to qualifying as an at risk category
Define IUCN Red list categories:
7. Least Concern (LC)
- species not NT or in a threatened category (widespread and abundant sp)
Define IUCN Red list categories:
8. Data deficient (DD)
- not enough info to make a determination
Define IUCN Red list categories:
9. Not evaluated
species has not been evaluated yet
Define IUCN Red list categories:
10. Regionally Extinct (RE)
- no longer exists in a region of interest but does elsewhere
Define IUCN Red list categories:
11. Not applicable (NA)
- species not eligible for regional red list bc introduced or only a rare migrant in area
Who determines which species are at risk?
- Natural heritage Data Centre?
- Natural Heritage Data Centres
L> continental US, 3 provinces and 14 Latin American countries
L>collects , organizes, manages info about conservation interest targets
L> ranks based on number of remaining pops, number of remaining individuals / extent of remaining area, number of protected sites, degree of threat and innate vulnerability
L> ranked 1 (critically imperilled) to 5 on global, national or regional scale
L> includes X (extinct), H(historically known), Unknown category
L> public access
** Supported by Nature Conservancy and COSEWIC
Who determines which species are at risk?
- Living planet Index
- monitors vert sp using IUCN criteria
- globally and by region
- found that half of Canadas wildlife is declining
Who determines which species are at risk?
- COSEWIC
- Committee on status of endangered wildlife in Canada
L> relies on info from other sources (living planet etc)
L> decision tree is ued ot track changes in status of sp already on national red list, determines status of previously DD etc
Who determines which species are at risk ?
- IUCN
- Natural heritage data centres
- Living Planet Index
- COSEWIC
What are the main types of at risk species?
- Narrow geographic range
L> endemic to one area
L> esp vulnerable on islands or alpine regions
*one type of rare sp - One/ few populations
L> increased risk bc of stochastic processes
L> sp with narrow ranges also fall in this category usually…
*one type of rare sp - Small population sizes
L> increased risk of extinction bc of previously mentioned reasons
** another type of rare sp - Declining populations
- hunted species
L> overexploitation can cause sp sizes to decline rapidly, especially if there are no regulations in place or if individuals/groups ignore them
What are some other species types that likely make them at increased risk of extinction?
- area demanding species
L> large home range
L> fragmentation can be a huge issue
L> ex jaguars, caribou - large body sizes/ low reproductive rate
- poor dispersers
- seasonal migrants or other sp that rely on two or more habitats for entire life cycle
- species that lack genetic diversity (ex small pops)
- specialists with specific niche requirements
- species found in undisturbed environments or that have had no contact with humans..more sensitive than
- species that are susceptible to allee effects (ex small pops)
- species with closer relatives that are at risk
**species at highest risk likely fall in more than one category
What makes migratory species vulnerable to extinction?
- many flyways in danger due to habitat destruction
- flyways likely shift temporarily/ spatially (climate change)
- flyway = migratory path used
What species are often keystone species?
- large predators (long lived, long gestation etc)
- top down regulation
