“The first animal species to go are the big, the slow, the tasty, and those with valuable parts such as tusks and skins.”

E.O. Wilson

Endangered and Extinct Species

Sustaining Biodiversity

Species Extinction

• Local extinction: when a species is no longer found in an area it once inhabited but is still found elsewhere in the world.

• Ecological extinction: when so few members survive that the species no longer play its ecological role in their communities.

• Biological extinction: when a species is no longer found on earth. This is forever.

Not yet extinct…

• Vulnerable or threatened species: still abundant in its natural range but because of declining numbers is likely to become endangered.

• Endangered species: has so few individual survivors that the species could soon become extinct over all or most of it natural range.

The Sixth Extinction

• Background extinction rate: one species per million per year, or 0.0001%

• Conservative estimate on current extinction rate: 1,000 to 10,000 species per million per year, or 0.1% to 1%

• If there are currently around 7 million species, how long would it take to lose half of them?

Could it be worse?

Is anything benefitting?

OK, soooo, what’s the big deal?

• Rebuilding biodiversity takes a long time.• Economic value of species (instrumental

value).• Recreational use (eco-tourism).• Intrinsic value.

Extinction Threats

• Habitat loss– Greatest threat to wild species– Islands species are at greatest

risk– Deforestation– Destruction of wetlands– Plowing of grasslands

• Agriculture• Commercial development• Water development• Outdoor recreation (off-road

vehicles)• Livestock grazing• pollution

Water Development

Extinction Threats• Habitat Fragmentation

– Large, continuous area of habitat is reduced, divided, scattered, or isolated.

– Species at special risk…• Rare• Need to roam unhindered• Low reproductive capacity• Specialize niches

– Divides species into smaller groups which make them more vulnerable.• Invasion of competitive species• Predators• Disease• Storms or fires• Barriers for dispersal and gene flow

Extinction Threats• Poaching and Hunting– Two-third of animals illegally smuggled around the world

die in transit.– Poverty is a contributing factor.– China: world’s largest consumer of wildlife– Bushmeat

Extinction Threats• Predator Control– Exterminate species

that compete with us for food and game animals.

• Legal and illegal trade for exotic pets and plants

• Climate change and pollution– Species can not

adapt fast enough

Is there any hope?

• There are treaties and laws in place both nationally and internationally that try to protect and conserve endangered species:– 1975 Convention on International Trade in

Endangered Species (CITES)– Convention on Biological Diversity (CBD)

Do you think these can be effective? Why or why not?