Biodiversity What is Biodiversity? The number and variety of different species in a given area.

Number of Species on Earth  1.9 million known species  Estimated 9 million species exist. May exist in remote wildernesses, deep in the oceans and even in cities. They have not been collected and classified. May exist in remote wildernesses, deep in the oceans and even in cities. They have not been collected and classified.

Levels of Diversity  Species diversity- refers to the number of different species in an area.  Ecosystem diversity- refers to the variety of habitats, communities, and ecological processes within and between ecosystems.  Genetic diversity- refers to all the different genes contained within all members of a population.

Benefits of Diversity  More species that exist, the better the balance in an ecosystem.  Medical- 74% of the top 150 prescription drugs used in the US are derived from plants.  Food- most crops originated from a few areas of high biodiversity.  Aesthetic or personal enjoyment  Clean air, clean water and fiber for clothing.

Biodiversity at Risk  Humans are the primary cause of species extinctions!!

Lemurs  90% of Lemur species face extinction.  Only found in Madagascar.  Reason: Illegal logging of tropical rainforests. Only 18% of rain forest remain. Illegal logging of tropical rainforests. Only 18% of rain forest remain.

Core Case Study: The Passenger Pigeon - Gone Forever  Once the most numerous bird on earth.  In 1858, Passenger Pigeon hunting became a big business.  By 1900 they became extinct from over- harvest and habitat loss. Figure 11-1

SPECIES EXTINCTION  Species can become extinct: Locally: A species is no longer found in an area it once inhabited but is still found elsewhere in the world. Locally: A species is no longer found in an area it once inhabited but is still found elsewhere in the world. Ecologically: Occurs when so few members of a species are left they no longer play its ecological role. Ecologically: Occurs when so few members of a species are left they no longer play its ecological role. Globally (biologically): Species is no longer found on the earth. Globally (biologically): Species is no longer found on the earth.

Global Extinction  Some animals have become prematurely extinct because of human activities. Figure 11-2

Fig. 11-2, p. 223 Aepyornis (Madagascar) Passenger pigeonGreat aukDodoDusky seaside sparrow

Endangered and Threatened Species: Ecological Smoke Alarms  Endangered species: so few individual survivors that it could soon become extinct.  Threatened species: still abundant in its natural range but is likely to become endangered in the near future. Figure 11-3

Fig. 11-3, p. 224 Hawksbill sea turtle Giant panda Black-footed ferret Whooping crane Northern spotted owl Blue whale Mountain gorilla Florida panther California condor Black rhinoceros

HABITAT LOSS, DEGRADATION, AND FRAGMENTATION  Conservation biologists summarize the most important causes of premature extinction as “HIPPO”: Habitat destruction, degradation, and fragmentation Habitat destruction, degradation, and fragmentation Invasive species Invasive species Population growth Population growth Pollution Pollution Overharvest Overharvest

 Some species have characteristics that make them vulnerable to ecological and biological extinction. SPECIES EXTINCTION Figure 11-4

Fig. 11-4, p. 225 Low reproductive rate (K-strategist) Specialized niche Narrow distribution Feeds at high trophic level Fixed migratory patterns Rare Commercially valuable Large territories Characteristic Blue whale, giant panda, rhinoceros Blue whale, giant panda, Everglades kite Many island species, elephant seal, desert pupfish Bengal tiger, bald eagle, grizzly bear Blue whale, whooping crane, sea turtles Many island species, African violet, some orchids Snow leopard, tiger, elephant, rhinoceros, rare plants and birds California condor, grizzly bear, Florida panther Examples

SPECIES EXTINCTION  Scientists use measurements and models to estimate extinction rates. The International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List, listing the world’s threatened species. The International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List, listing the world’s threatened species. The 2004 Red List contained 15,589 species at risk for extinction. The 2004 Red List contained 15,589 species at risk for extinction Red list now contains 22,000 species at risk for extinction Red list now contains 22,000 species at risk for extinction. Figure 11-5

SPECIES EXTINCTION  Percentage of various species types threatened with premature extinction from human activities. Figure 11-5

Fig. 11-5, p % Birds Plants Reptiles Mammals Fish 34% (51% of freshwater species) 25% 20% 14%

Coral Reefs  60% of Earth’s coral reefs are threatened by human activities: overfishing, and pollution.

HABITAT LOSS, DEGRADATION, AND FRAGMENTATION  Reduction in ranges of four wildlife species, mostly due to habitat loss and overharvest. Figure 11-8

Fig. 11-8a, p. 230 Range 100 years ago Indian Tiger Range today (about 2,300 left)

Fig. 11-8b, p. 230 Range in 1700 Black Rhino Range today (about 3,600 left)

Fig. 11-8c, p. 230 Probable range 1600 African Elephant Range today

Fig. 11-8d, p. 230 Range today (34,000–54,000 left) Asian or Indian Elephant Former range

Case Study: A Disturbing Message from the Birds  Human activities are causing serious declines in the populations of many bird species. Figure 11-9

Pollution  Each year pesticides: Kill about 1/5 th of the U.S. honeybee colonies. Kill about 1/5 th of the U.S. honeybee colonies. 67 million birds. 67 million birds million fish million fish. Threaten 1/5 th of the U.S.’s endangered and threatened species. Threaten 1/5 th of the U.S.’s endangered and threatened species. Example of biomagnification of DDT in an aquatic food chain. Figure 11-15

Fig , p. 237 DDT in water ppm, or 3 ppt DDT in fish-eating birds (ospreys) 25 ppm DDT in large fish (needle fish) 2 ppm DDT in small fish (minnows) 0.5 ppm DDT in zooplankton 0.04 ppm

PROTECTING WILD SPECIES: LEGAL AND ECONOMIC APPROACHES  International treaties have helped reduce the international trade of endangered and threatened species, but enforcement is difficult. One of the most powerful is the 1975 Convention on International Trade of Endangered Species (CITES). One of the most powerful is the 1975 Convention on International Trade of Endangered Species (CITES). Signed by 169 countries, lists 900 species that cannot be commercially traded.Signed by 169 countries, lists 900 species that cannot be commercially traded.

Case Study: The U.S. Endangered Species Act  One of the world’s most far-reaching and controversial environmental laws is the 1973 U.S. Endangered Species Act (ESA). ESA forbids federal agencies (besides defense department) to carry out / fund projects that would jeopardize an endangered species. ESA forbids federal agencies (besides defense department) to carry out / fund projects that would jeopardize an endangered species. ESA makes it illegal for Americans to engage in commerce associated with or hunt / kill / collect endangered or threatened species. ESA makes it illegal for Americans to engage in commerce associated with or hunt / kill / collect endangered or threatened species.

Endangered Species  Because of scarcity of inspectors, probably no more than 1/10 th of the illegal wildlife trade in the U.S. is discovered. Figure 11-19

PROTECTING WILD SPECIES: THE SANCTUARY APPROACH  The U.S. has set aside 544 federal refuges for wildlife, but many refuges are suffering from environmental degradation. Pelican Island was the nation’s first wildlife refuge. Figure 11-20

Fig , p. 246 Do not buy furs, ivory products, and other materials made from endangered or threatened animal species. Do not buy wood and paper products produced by cutting remaining old- growth forests in the tropics. Do not buy birds, snakes, turtles, tropical fish, and other animals that are taken from the wild. Do not buy orchids, cacti, and other plants that are taken from the wild. Spread the word. Talk to your friends and relatives about this problem and what they can do about it. What Can You Do? Protecting Species