Lecture 7 Extinctionsd1229/444/2008/7. Extinction.pdf · 2008. 9. 29. · 9/29/2008 6 Extinction...
Transcript of Lecture 7 Extinctionsd1229/444/2008/7. Extinction.pdf · 2008. 9. 29. · 9/29/2008 6 Extinction...
-
9/29/2008
1
Lecture 7
Extinction
Extinction:
I. Species of the Day
II. Some Definitions
III. Past Mass Extinctions
IV. The Current Mass Extinction
V. Extinction Rates
VI. Who goes extinct?
VII.In-situ Conservation Strategies
-
9/29/2008
2
Species of the Day:
Gray wolfCanis lupus
Federal – 1967Endangered
2006 – Delisted Great Lakes2008- Mtn. – Prairie Region
Under Review
Some Definitions:
• Extinct
• Extinct in the wildExtinct in the wild
• Globally extinct
• Locally extinct
• Ecologically extinctBlack Footed Ferret
Passenger Pigeon Grizzly Bear
-
9/29/2008
3
Past Mass Extinctions:
Past Mass Extinctions:
Prehistoric Mega-faunal Extinction:
North America - 10 000 to 4000 years agoNorth America - 10,000 to 4000 years ago
• Mammoth• Mastodons• Camels• Ground sloths• Sabertooth cats• Short-faced bear
-
9/29/2008
4
Past Mass Extinctions:
Prehistoric Mega-faunal Extinction:
Australia - 60 000 to 50 000 years ago:Australia - 60,000 to 50,000 years ago:
• Giant herbivorous and carnivorous kangaroos
• Various marsupial species• Many reptiles and birds• Greater diversity of species
compared to North America
Current Mass Extinction
-
9/29/2008
5
Extinction:
Extinction Rates:
Background Extinction Rates:
B k d t 0 0001 0 00001%Background rate = 0.0001-0.00001%Mammals & Birds = 0.01%
(E.O. Wilson et al. 2000)
-
9/29/2008
6
Extinction Rates:
Extinction Rates on Islands:
Extinction Rates:
Extinction Rates in Water:
• 12 species (3 marine mammals 5 marine birds • 12 species (3 marine mammals, 5 marine birds, & 4 mollusks)
• 1/3 of freshwater fish species are in danger of extinction (in North America)
• 7% of California’s native fish are extinct and 56% are in danger of becoming extinct
Devils Hole pupfish
-
9/29/2008
7
Who Goes Extinct?
Why do species go extinct?
• Something causes a large population to decline • Something causes a large population to decline.
• Small populations go extinct.
What is rarity?
• A species that lives in a narrow range.
• A species that occupies only one or a few specialized habitats.
• A species that is found only in small populations• A species that is found only in small populations.
Who Goes Extinct?
-
9/29/2008
8
Extinction:
Ex Situ and In Situ Conservation Strategies
Extinction:
Ex Situ Conservation Facilities
• Zoos
Captive Breeding Programs
• Aquariums
• Botanical Gardens and Arboretums
Seed banks
Agricultural seed bank
Tree clone banks
-
9/29/2008
9
Extinction:
Approaches to Establishing New Populations:
1. Reintroduction
2. Augmentation program
3. Introduction program
Green Sea TurtleChelonia mydas
Black footed FerretMustela nigripes