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Factors of Extinction Why are some species more or less prone to extinction? Niche Species who have a specialized niche are more prone to extinction. Source: http://www.destination360.com/north-america/us/alaska/alaska-whale-watching.php Source: http://www.biojobblog.com/tags/panda/

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Factors of Extinction

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factors of extinction

Factors of Extinction

Why are some species more or less prone to extinction?

  • Species who have a specialized niche are more prone to extinction.

Source: http://www.destination360.com/north-america/us/alaska/alaska-whale-watching.php

Source: http://www.biojobblog.com/tags/panda/

Source: http://www.koalas.org/koala-australia.html

  • Over specialization of feeding
  • Over specialization of habitat
low reproductive rate

Source: http://www.pbase.com/johncarol/image/73692533

Source: http://www.srgc.org.uk/bulblog/log2007/100107/log.html

Low Reproductive Rate
  • r versus K strategists
predators and man

Source: http://www.nytimes.com/2006/07/16/world/europe/16tuna.html

Source: http://www.awf.org/section/wildlife/elephants

Source: http://animals.nationalgeographic.com/animals/mammals/wolf.html

Predators and Man
  • Man preying on species
    • Hunting
    • Trade
  • Species preying on man or livestock
  • Large bodied animals are hunted for sport
trophic level
Trophic level
  • Higher up in the food chains are more susceptible

Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/i/indian-tiger-india-512815-ga.jpg

interspecific competition
Interspecific Competition
  • Nesting sites
  • Food
  • Breeding
  • Habitat

Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/a/axis-deer-512754-ga.jpg

  • Migratory Patterns
    • Fixed
    • Flexible
    • Both habitats are needed
    • Barriers to the path

Source: http://www.ag.gov.au/www/agd/rwpattach.nsf/VAP/(454DFAFE2D6830FB1D0597823A67B5D6)~red+crabs+migration.JPG/$file/red+crabs+migration.JPG

Source: http://www.sciencedaily.com/releases/2008/01/080108083008.htm

  • Narrow geographical range is more dangerous. Examples: Golden lion tamarin, birds on islands…

Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/p/polar-bear-cubs-492324-ga.jpg

Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/g/grassland-kangaroos-76934-ga.jpg

overall numbers
Overall Numbers
  • The lower the numbers the more prone
  • Low population densities
  • Few populations of the species

Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/b/baby-gorilla-gabon-651797-ga.jpg

Source: http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/platypus.jpg

strategies for success
Strategies for Success
  • Generalists over specialists
  • Diversity
    • Of ecosystems
    • Complexity of food webs
  • Inertia/Constancy
  • Resilience

Source: http://www.staringspestandrodentcontrol.com/files/images/American-cockroach.preview.jpg

categories and criteria

Categories and Criteria

from: The IUCN Red List of Threatened Species

conservation status
Conservation Status
  • Extinct (EX) – there is no reasonable doubt that the last individual has died
  • Extinct in the Wild (EW) – Known only to survive in cultivation, in captivity, or as a naturalized population well outside the past range
  • Critically Endangered (CR) – Facing an extremely high risk of extinction in the wild
  • Endangered (EN) – Facing a very high risk of extinction in the wild
  • Vulnerable (VU) – Facing a high risk of extinction in the wild
criteria for cr en and vu
Criteria for CR, EN and VU
  • Reduction of population size by W% over 10 years or 3 generations
  • Size of geographic range
  • Population size of mature individuals less than X with continued decline of Y% over 10 years or 3 generations
  • Population size of mature individuals less than Z
  • Quantitative analysis showing the probability of extinction in the wild
conservation status16
Conservation Status
  • Near Threatened (NT) – Close the qualifying for a threatened category in the near future
  • Least Concern (LC) – Widespread abundant taxa are included in this category
conservation status17
Conservation Status
  • Data Deficient (DD) - there is inadequate information to make an assessment of the risk of extinction
  • Not Evaluated (NE) – has not been evaluated against criterion