Conservation Chapter 14

Wildlife Resources  What is happening to the wildlife and plant resources around us today?

U.S. Species Diversity

Decreasing Biodiversity  10-20% of species alive in 1975 were extinct in 2000  Mostly plants, invertebrates in tropical rain forests (many undescribed species)  40% of all species live in tropical areas  Disappear along with forests

Extinction Not New  99% of all species have gone extinct  Gradual environmental changes have been responsible for most extinctions  Rapid environmental changes from asteroids, etc. also have been important in many extinctions

Extinction Rates  Background (natural) rate of extinction  Mass extinction

Why Should We Care About Extinctions and Biodiversity? 1) economics 2) aesthetics 3) ecological 4) ethics

Cinchona Cinchona ledogeriana, South America Quinine for malaria treatment

Rauvolfia Rauvolfia sepentina, Southeast Asia Tranquilizer, high blood pressure medication

Foxglove Digitalis purpurea, Europe Digitalis for heart failure

Pacific yew Taxus brevifolia, Pacific Northwest Ovarian cancer

Human Impacts on Biodiversity

Flathead Lake, Montana

Causes of Premature Extinction of Wild Species

Human Activities That May Cause Extinctions  Habitat disturbance/destruction  Commercial hunting  Predator and pest control  Collecting for pets, zoos, research  Pollution  Introductions of exotic species

Habitat Disturbance and Destruction California Condor

Commercial Hunting Black Rhino Range in 1700 Range today (about 2,400 left)

Predator and Pest Control African Elephant Probable range 1600 Range today (300,000 left)

Collecting for Pets, Zoos, Research

Pollution Bald Eagle - DDT

Species Introductions Dodo Bird Zebra Mussel

Threats from Nonnative Species

Strategies for Protecting Biodiversity  Species approach  Ecosystem approach

Protecting Wild Species: The Legal Approach  International Treaties: CITES - Convention on International Trade in Endangered Species  National Laws:ESA - Endangered Species Act

Protecting Wild Species: The Sanctuary Approach  Wildlife refuges and protected areas - e.g. whooping cranes  Zoos and Aquariums - captive breeding programs  Gene banks, botanical gardens, and farms

The Ecosystem Approach  Biosphere reserves  U.S. has >30 reserves - Yellowstone National Park - Great Smoky Mtns. National Park  Other countries have similar reserves

The Ecosystem Approach

Bird Success Stories California Condor Whooping Crane Peregrine Falcon Canada Goose Wild Turkey