Post on 11-Jan-2016
transcript
Factors of Extinction
Why are some species more or less prone to extinction?
Specialization
Source: http://www.destination360.com/north-america/us/alaska/alaska-whale-watching.php
Source: http://www.koalas.org/koala-australia.html
Source: http://www.biojobblog.com/tags/panda/
Overspecialization of feeding Over specialization of habitat
Reproductive Rate
Source: http://www.pbase.com/johncarol/image/73692533
Source: http://www.srgc.org.uk/bulblog/log2007/100107/log.html
r versus K strategists
Prey/Man
Source: http://www.awf.org/section/wildlife/elephants
Source: http://www.nytimes.com/2006/07/16/world/europe/16tuna.html
Source: http://animals.nationalgeographic.com/animals/mammals/wolf.html
Man preying on species Hunting Trade
Species preying on man or livestock
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
Nesting sites Food Breeding Habitat
Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/a/axis-deer-512754-ga.jpg
Behavior
Migratory Patterns Fixed Flexible
Source: http://www.sciencedaily.com/releases/2008/01/080108083008.htm
Source: http://www.ag.gov.au/www/agd/rwpattach.nsf/VAP/(454DFAFE2D6830FB1D0597823A67B5D6)~red+crabs+migration.JPG/$file/red+crabs+migration.JPG
Distribution
The more limited the more prone
Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/g/grassland-kangaroos-76934-ga.jpg
Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/p/polar-bear-cubs-492324-ga.jpg
Overall Numbers
The lower the numbers the more prone
Source: http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/platypus.jpg
Source: http://photography.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/Photography/Images/POD/b/baby-gorilla-gabon-651797-ga.jpg
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
from: The IUCN Red List of Threatened Species
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
Threatened
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
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 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 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