Table of Contents

Introduction
The pathology of extinction
- Rates of natural and present-day species extinction
  - How many species are there?
  - Calculating background extinction rates
  - Recent extinction rates
    - Pacific island birds
    - Flowering plants
    - Freshwater mussels and clams
    - Freshwater fish
    - Australian mammals
  - Calculating relative rates of extinction
  - Predicting future rates of extinction
    - Inexorable declines
    - Surviving but threatened small populations
    - The loss of populations
    - The loss of ecosystems
- Factors that cause extinction
  - Habitat loss
    - On land
      Endemic species
      Range size
      Terrestrial hot spots
      Predictions of extinctions based on habitat loss
      Fire suppression as habitat loss
    - In the oceans
    - In fresh water
  - Pollution
  - Introduced species
  - Overharvesting
    - Whaling
    - Fishing
    - Logging and collecting
  - Secondary extinctions
  - Global warming
- Which species are most vulnerable to extinction?
  - Endemism and rarity
  - Body size and related reproductive characteristics
  - Behaviour
    - Size of home range
    - Concentration
    - Low dispersal
    - Mating systems
  - Insularity
  - Human use
Preventing the loss of biodiversity
- Species interventions
  - Protective custody
  - Genetic intervention
  - Associated difficulties and costs
    - Protecting species
    - Removing invasive species
    - Introducing species
- Habitat protection
- Habitat connections
- Habitat management
  - Fire control
  - Flood control
- Habitat restoration
- Putting a price on conservation

Fast Facts

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Media

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conservation: Media

ecology

Videos

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Learn how the Brazilian government incentivized forest clearing in the Amazon for beef production and ranching

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Encyclopædia Britannica, Inc.

Understand how overfishing and climate change lead to the depletion of worldwide fish population

Understand how overfishing and climate change lead to the depletion of worldwide fish population

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Contunico © ZDF Studios GmbH, Mainz; Thumbnail © Banol2007/Dreamstime.com

Investigate declines in tiger populations threatened by habitat fragmentation and illegal hunting

Investigate declines in tiger populations threatened by habitat fragmentation and illegal hunting

Learn about declines in tiger populations.

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Learn about efforts to protect the Seychelles' wildlife.

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Learn how the camera traps help capture images of wild animals in their natural behaviors and habitats

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© American Chemical Society (A Britannica Publishing Partner)

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Learn about the efforts of AfriCat Foundation to protect the cheetahs in Namibia

Learn about efforts to protect cheetahs in Namibia.

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© MinuteEarth (A Britannica Publishing Partner)

Learn how invasive species and habitat destruction have threatened Hawaii's yellow-faced bees

Learn how invasive species and habitat destruction have threatened Hawaii's yellow-faced bees

Learn about conservation efforts to help the endangered yellow-faced bee, whose populations...

Encyclopædia Britannica, Inc.

Learn why the construction of dykes is crucial in protecting the north German coastlines

Learn why the construction of dykes is crucial in protecting the north German coastlines

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Understand how biodiversity is a boon for the economy

Understand how biodiversity is a boon for the economy

Why biodiversity is good for the economy.

© MinuteEarth (A Britannica Publishing Partner)

Know about the exploitation of animals, the darker side of animal tourism

Know about the exploitation of animals, the darker side of animal tourism

How the animal tourism industry exploits animals.

© Behind the News (A Britannica Publishing Partner)

Know the importance of maintaining genetic diversity during the breeding programs of endangered species in captivity

Know the importance of maintaining genetic diversity during the breeding programs of endangered species in captivity

Why genetic diversity is important when breeding animals in captivity.

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Know why India's Ganges River and its tributary the Yamuna River, as well as New Zealand's Whanganui River, were granted the same legal rights as people in 2017

Know why India's Ganges River and its tributary the Yamuna River, as well as New Zealand's Whanganui River, were granted the same legal rights as people in 2017

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Learn about the efforts of the Afri-Leo Foundation to protect the lions in Namibia

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Learn about efforts to protect lions in Namibia.

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Learn how ecotourism at the Monteverde Cloud Forest Biological Reserve in Costa Rica helps conservation and the lives of the residents

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Hear how the physical appearance of certain animals influence in saving endangered species at the expense of rational conservation approach

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Learn about the conservation efforts to protect the marine ecosystem of the St. Anne Marine National Park, Seychelles

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Overview of conservation efforts in the Seychelles.

Contunico © ZDF Studios GmbH, Mainz; Thumbnail © Zi Magine/Dreamstime.com

Images

Terrestrial hot spots of biodiversity

Terrestrial hot spots of biodiversity

Encyclopædia Britannica, Inc.

bracket fungus

bracket fungus

Saprotrophic bracket fungi decomposing a dead tree.

Encyclopædia Britannica, Inc.

dandelion

dandelion

Dandelion (Taraxacum officinale).

Alan Punton/A to Z Botanical Collection

plesiosaur fossil

plesiosaur fossil

Fossil of the plesiosaur Cryptocleidus, a large marine reptile of the Jurassic...

Courtesy of the American Museum of Natural History, New York

species of apes

species of apes

Representative apes (superfamily Hominoidea).

Encyclopædia Britannica, Inc.

phylogenetic tree

phylogenetic tree

Phylogeny based on differences in the protein sequence of cytochrome c in organisms...

Encyclopædia Britannica, Inc.

western bluebird

western bluebird

Western bluebird (Sialia mexicana).

Herbert Clarke

eastern bluebirds

eastern bluebirds

Eastern bluebirds (Sialia sialis).

© Index Open

dodo

dodo

Dodo (Raphus cucullatus).

Encyclopædia Britannica, Inc./Christine McCabe

Cape sugarbird and king protea

Cape sugarbird and king protea

Cape sugarbird (Promerops cafer) perched on a flower of the king protea...

© Nigel J. Dennis, The National Audubon Society Collection/Photo Researchers

thylacine

thylacine

The Tasmanian tiger—also called the thylacine or Tasmanian wolf—was a carnivorous...

Encyclopædia Britannica, Inc.

California condor

California condor

California condor (Gymnogyps californianus).

John Borneman—The National Audubon Society Collection/Photo Researchers

plastic pollution

plastic pollution

Dowitcher bird (Limnodromus species) standing on a pile of garbage.

© gaurav_gadani/iStock.com

tropical forests and deforestation

tropical forests and deforestation

Tropical forests and deforestation in the early 21st century.

Encyclopædia Britannica, Inc.

Everglades marsh

Everglades marsh

A freshwater marsh, dominated by saw grass and dotted by palms and cypresses, in...

Jeff Greenberg/Peter Arnold, Inc.

apapane

apapane

Apapane (Himatione sanguinea).

Drawing by John P. O'Neill

Brazil

Brazil

The coastal forest of Rio de Janeiro state, Brazil, badly fragmented as portions...

Courtesy, Stuart L. Pimm

passenger pigeon

passenger pigeon

The last known passenger pigeon died in 1914.

Encyclopædia Britannica, Inc.

coral reef

coral reef

Between 4,000 and 5,000 species of fish—perhaps a third of the world's marine fish—live...

© Digital Vision/Getty Images

European, or common, starling

European, or common, starling

European, or common, starling (Sturnus vulgaris).

George W. Robinson—Root Resources/Encyclopædia Britannica, Inc.

Brown tree snake (Boiga irregularis)

Brown tree snake (Boiga irregularis)

Brown tree snake (Boiga irregularis).

USDA/APHIS

rufous fantail

rufous fantail

Rufous fantail (Rhipidura rufifrons)

E. McNamara—Ardea, London

breaching humpback

breaching humpback

Humpback whale (Megaptera novaeangliae) breaching.

Al Giddings/Images Unlimited

whaling

whaling

Japanese factory ship hauling a minke whale through a slipway in the ship's stern,...

Culley/Greenpeace

aquatic food web

aquatic food web

Generalized aquatic food web showing the network of feeding relationships that exist...

Encyclopædia Britannica, Inc.

mamo

mamo

Mamo (Drepanis pacifica), a nectar-feeding honeycreeper.

Painting by H. Jon Janosik

carbon dioxide emissions

carbon dioxide emissions

Map of annual carbon dioxide emissions by country in 2014.

Encyclopædia Britannica, Inc.

American songbirds

American songbirds

Distribution of songbirds in North and South America.

Encyclopædia Britannica, Inc.

Baikal seals

Baikal seals

Baikal seals (Phoca sibirica), endemic to Lake Baikal, southeastern Siberia,...

© Doug Allan/Oxford Scientific Films Ltd.

elephant seal

elephant seal

Northern elephant seal (Mirounga angustirostris).

© Radkol/Dreamstime.com

Florida panther

Florida panther

Florida panther (Puma concolor coryi).

Courtesy, Stuart L. Pimm

bald eagle

bald eagle

Bald eagle (Haliaeetus leucocephalus).

Alan & Sandy Carey/Getty Images

white rhinoceros

white rhinoceros

White rhinoceros (Ceratotherium simum), Mkuze Game Reserve, South Africa.

© Digital Vision/Getty Images

Exxon Valdez oil spill

Exxon Valdez oil spill

Workers cleaning rocks coated in oil from the Exxon Valdez, an oil tanker than ran...

Exxon Valdez Oil Spill Trustee Council/NOAA (ID: line1532)

Podcasts

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