Download Sustaining Biodiversity - species Mass extinction events Levels of

Sustaining Biodiversity ‐ species
Background extinction rates – estimate 1 species / million species / year (0.0001%/year)
Current estimates – 100X background rates, primarily due to human activities (0.001%/ year)
Still seems pretty small…and there’s the planet’s whole mass extinction history… so, why worry?
Current habitat destruction, hunting, etc. estimated to increase extinction rate to 0.1 to 1% /year by end of century.
Levels of extinction
Photo: USFWS
Local: Mexican grey wolf in American Southwest
Reintroduced to N.M., Arizona by USFW Service – (grey wolf in Yellowstone another example)
Ecological: Sea otters
Reduced numbers in Aleutean Islands lead to increase in sea urchins; kelp forests devastated
(photo: www.turtletrack.org)
At 1% extinction rate, ¼ to ½ of current species could vanish by end of century; RATE is faster than EVER estimated, even during previous mass extinctions.
Humans not present during previous mass extinctions…
Mass extinction events Biological: Golden toad, adapted to cloud forests
Associated with climate change (no more “cloud” in the forest!)
www.amersol.edu.pe
Endangered species: how different from threatened species?
Grizzly bear
Utah prairie dog
Kirkland’s warbler
Knowlton cactus
Swallowtail butterfly
Humpback chub
Florida manatee
African elephant
Golden lion Siberian tiger
tamarin
Fig. 5‐2a, p. 95
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IUCN, International Union for Conservation of Nature monitors threatened, endangered and extinction of species globally IUCN REDLIST: http://www.iucnredlist.org/
Characteristic
Low reproductive rate
Specialized niche
Giant panda
Black‐footed ferret
Whooping crane
Northern spotted owl
Blue whale
Elephant seal, desert pupfish
Feeds at high trophic level
Bengal tiger, bald eagle, grizzly bear
Fixed migratory patterns
Commercially valuable
Florida panther
California condor
Hawksbill sea turtle
Black rhinoceros
Blue whale, giant panda, Everglades kite
Narrow distribution
Rare
Mountain gorilla
Examples
Blue whale, giant panda, rhinoceros
Blue whale, whooping crane, sea turtle
African violet, some orchids
Snow leopard, tiger, elephant, rhinoceros, rare plants and birds
Large territories
Fig. 5‐2b, p. 95
California condor, grizzly bear, Florida panther
Fig. 5‐3, p. 96
What is the value of a species?
Red list also monitors extinctions: 9 Biological extinction 9 Local / subspecies extinctions
http://usatoday30.usatoday.com/news/world/environment/story/2011‐11‐10/africa‐rhino‐extinct/51149676/1
Fig. 5‐6b, p. 100
Ecological value: Lions as top predators
Economic value:
How much is one lion worth in ecotourism dollars over its lifetime, vs. its value for its pelt?
Ecological value ‐ diversity
Economic value ‐ are wild fisheries affected?
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Plants as medicines
Pacific yew taxol
Success!
• Prowolski Horses –
Native to Mongolia’s Gobi Desert
• Extinct in wild –
reintroduced from zoo populations
Opium poppy morphine
Eucalyptus menthol
Ephedra
nasal decongestant
animal.discovery.com
Jairo S. Feris Delgado Southern Resident Orca population Listed Endangered
Underlying causes
• Population growth
• Rising resource use
• Undervaluing natural capital
http://www.psp.wa.gov/vitalsigns/orcas.php
Made up of J, K and L pods (family groups)
http://www.care2.com/news/member/285806679/614303
http://whaleresearch.com/
J pod = 25 individuals
K pod = 20 individuals
L pod = 40 individuals
• Poverty
Direct causes
• Habitat loss
• Habitat loss
• Pollution
• Commercial hunting and poaching
• Habitat degradation and fragmentation
• Habitat degradation and fragmentation
• Climate change
• Sale of exotic pets and decorative plants
• Introduction of nonnative species
• Overfishing
• Predator and pest control
• Introduction of nonnative species
http://westseattleblog.com/2011/10/video‐what‐the‐orcas‐did‐on‐the‐other‐side‐of‐puget‐sound
Fig. 5‐5, p. 99
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Some deliberate introductions are not so good…
HIPPCO
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European wild boar (Southeast U.S.)
HABITAT destruction/degradation
INVASIVE species
POPULATION growth
POLLUTION
CLIMATE CHANGE
OVEREXPLOITATION
Invasive water hyacinth
Many insect, plant, and aquatic invaders are accidental introductions
How do they get here?
Most deliberate introductions are useful for humans
Accidental introductions
Argentina fire ant
Crops for food
http://cisr.ucr.edu/
Many insect, plant, and aquatic invaders are accidental introductions
BJORN SVENSSON How can these lead to species extinctions? Reduce genetic
biodiversity?
ROGER STANDEN How do they get here?
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Climate change can lead to habitat loss
Fig. 5‐10, p. 103
DDT in fish‐eating birds (ospreys) 25 ppm
Biomagnification
DDT in large fish (needle fish) 2 ppm
DDT in small fish (minnows) 0.5 ppm
DDT in zooplankton
0.04 ppm
DDT in water
0.000003 ppm, or 3 ppt
Fig. 5‐11, p. 103
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