Why This Science Matters

San Diego County is the home for many different reptiles, amphibians, birds, insects, and mammals. Scientists from the U.S. Geological Survey study these animals in an effort to discover how the existence of these species affects our environment and local ecological system. The information provided by these studies is used to make predictions about how man and urbanization are impacting the future existence of many native animals in Southern California and what that will mean to our environment.

What is Biodiversity?
Biodiversity can be defined as a wide variety of different species living in the same area. There are fewer than 25 locations around the world in which scientists have identified environments that support a variety of animals living in close proximity. These areas are known as "hotspots". One such "hotspot" can be found in San Diego County.

Why protect the local fauna?
Biodiversity is important to man's existence. Species of all types play an important role in the ecological system found in nature. Several kinds of living groups depend on other living groups for food. For example, wolves sometimes eat birds, which eat insects, which eat plants. This process is called the food chain. The elimination of one species from this cycle can result in the deterioration or loss of the other living creatures that are dependent upon it as a food source. Disruptions to the food chain in man's past have had adverse effects on communities dependent on farming or hunting.

In addition, the destruction of fauna can have long-reaching implications for mankind. Many species are early indicators of pollution and environmental degradation that can affect human health. For example, in the 1970's scientists discovered that DDT, a poison once used by farmers to control insects, was polluting some lakes and rivers. The animals that were dependent on the water for survival began to die. DDT caused several species of animals living around these areas to become endangered and it was beginning to have dangerous effects on man. Although some people were adversely affected by the pollution created by the DDT poisoning, the impact could have been much more severe without the warning system provided by nature.

Protecting the local fauna can also have other benefits. Many different types of living things have the potential to become sources for new medicines or provide a natural protection against disease. The Western Fence Lizard is a great example of how a relatively small creature provides a natural protection for Lyme Disease. Ticks that carry the disease bite the lizard, and as a result, the Lyme disease bacteria inside of the tick is destroyed. Only recently did scientist discover the importance of the Western Fence Lizard and the benefits it was having on man.

It is every person's duty to protect the fauna of San Diego. San Diego is home to a variety of mammals, reptiles, amphibians, birds and insects. Many of these species are declining in number due to man's effect on the environment. However, many of these same species contribute to man's existence. Find a way to positively impact the biodiversity that exists in our community. Ask yourself this question: What you can do to make a difference?

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Explore This Topic

The following questions accompany this lesson. The answers are given below each question. To reveal an answer, place the cursor over "REVEAL THE ANSWER".

1. What is an endemic species?

2. What is the Western Fence Lizard and how does it prevent the transmission of Lyme disease in California?

3. How has man's search for recreation and food led to the demise of the Western Terrestrial Garter Snake?

4. What new information has been determined recently about Jerusalem Crickets?

5. How does man negatively impact Southern California's biodiversity?

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Links and Resources

Field Guide to San Diego Fauna

Reptiles and Amphibians of Coastal Southern California

Western fence lizard

Western fence lizard

Californian's Wildlife Reptiles

Red racer snake

Two-Striped Garter Snake

Jerusalem Cricket

Lyme Disease and Western fence Lizard

Endangered Species

Mountain Yellow-Legged Frog

National Parks Conservation Association: On the Rebound (mountain yellow-legged frogs)

A Field Guide to Reptiles and Amphibians of Coastal Southern California
Case, Ted and Robert Fisher. Ted Case: La Jolla, CA. 1997.

California's Wild Heritage: Threatened and Endangered Animals in the Golden State
Steinhart, Peter. Sierra Club: San Francisco, 1990.

Endangered Wildlife and Habitats in Southern California
Remington, Janet et al. Natural History Foundation of Orange County: San Juan Capistrano, CA. 1990.

California Endangered Species Resource Guide
California Department of Education: Sacramento, 1996.

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Lesson developed by Tracee Parsons, science teacher, The Preuss School.