Biology 1229 Extinction Extinction p the cessation of
Biology 1229 Extinction
Extinction p “the cessation of existence of a species”
IUCN categories p Extinct n No reasonable doubt that the taxon is gone. p 717 animal and 87 plant species since 1500
Lytta mirifica Thylacine Quagga Great Auk Stead’s Bush Wren Passenger Pigeon Labrador duck huia dodo Steller’s Sea Cow
IUCN categories p Extinct n in the wild Species only exists in captivity or cultivation p 37 animals and 28 plants
Extinct in the wild Hawaiian Crow St Helena Redwood Wood’s Cycad Partula snails Redtail Shark Black-footed ferret
IUCN categories p Critically n endangered Extremely high risk of extinction in the wild p 3240 species (up from 3124 in 2007 and 3071 in 2006) p Includes 6 species of fungi
North American Burying beetle Southern Bluefin Tuna Baiji Black Rhino Kakapo
IUCN categories p Endangered n Very high risk of extinction in the wild p 4768 species
IUCN categories p Vulnerable n High risk of extinction in the wild p 8911 species
IUCN categories p Near Threatened n n p Least concern n n p Ongoing conservation measures required to prevent risk of extinction 3513 Widespread, abundant & safe 17675 Data deficient n n No assessment possible 5561
Gaps in knowledge p Almost n all invertebrates Apart from ‘showy’ ones Collected beetles p Butterflies p Dragonflies p p Poor knowledge of tropics, esp. in Africa p The vast majority of described species are known from only a few specimens
A Global Extinction Crisis p >33% of frogs threatened p ¼ of Mammals face extinction p 15 -37% of species extinct by 2050 p 70% of Butterfly species in decline
Why should we care? p The sadness of losing biodiversity p Our moral responsibilities p Ecosystem services
Ecosystem services p All the free stuff we get from nature n Water purification, decomposition, dung removal, pollination, O 2 repletion, CO 2 absorption, food, pharmaceutical products etc. p $16 -54 Trillion (i. e. $16 000 000) per year… in 1997!
Why do species go extinct I? p Natural extinctions Population changes n Natural disasters n Evolution, migration and habitat change n
Why do species go extinct II? p Anthropogenic influence
Overkill Invasive species Climate Change Habitat destruction
The four horsemen of the extinction crisis I: Habitat destruction
The four horsemen of the extinction crisis II: Overkill
Stoat (NZ) NZ Flatworm (Ireland) House Mouse (Many places!) Emerald Ash Borer (SW ON) European Starling (Many places!) Rhododendron (Scotland) Red Fox (Australia) Brush-tailed possum (NZ) The four horsemen of the extinction crisis III: Invasive species Zebra Mussel (Great Lakes)
The four horsemen of the extinction crisis IV: Climate change
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