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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

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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

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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

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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

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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)

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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

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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?

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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

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Extinction:

Approaches to Establishing New Populations:

1. Reintroduction

2. Augmentation program

3. Introduction program

Green Sea TurtleChelonia mydas

Black footed FerretMustela nigripes