1. Ch 11 Species
Section 01
Section 02

2. A. SPECIES EXTINCTION The three levels of extinction are:
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.
Globally (biologically): Species is no longer found on the earth.

3. 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.
Show some information about bluefin tuna and it’s status
Figure 11-3

4. Swallowtail butterfly Humpback chub Golden lion tamarin Siberian tiger
Grizzly bear
Kirkland’s warbler
Knowlton cactus
Florida manatee
African elephant
Figure 11.3
Endangered natural capital: species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and 1,260 of those in the United States are officially listed as being in danger of becoming extinct. Most biologists believe the actual number of species at risk is much larger.
Utah prairie dog
Swallowtail butterfly
Humpback chub
Golden lion tamarin
Siberian tiger
Fig. 11-3, p. 224

5. Giant panda Black-footed ferret Whooping crane Northern spotted owl
Blue whale
Figure 11.3
Endangered natural capital: species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and 1,260 of those in the United States are officially listed as being in danger of becoming extinct. Most biologists believe the actual number of species at risk is much larger.
Mountain gorilla
Florida panther
California condor
Hawksbill sea turtle
Black rhinoceros
Fig. 11-3, p. 224

6. California Condor
SHOW
VIDEO

7. Biologists use measurements and models to estimate extinction rates
The first species to go tend to be the big, the slow and the tasty ones—ones whose valuable parts can be sold
Tigers bones
Rhino horns
Biologists use measurements and models to estimate extinction rates
Background extinction, mass extinctions, and mass depletions account for a loss of 99.9% of all species that have ever existed
Show video on player for illegal wildlife trade and depletion happening in the galapagos islands

8. Silurian Permian Jurassic Cambrian Ordovician Devonian Devonian
Terrestrial
organisms
Silurian
Permian
Jurassic
Cambrian
Ordovician
Devonian
Devonian
Cretaceous
Pre-cambrian
Carboniferous
Marine
organisms
Number of families
Tertiary
Quaternary
Figure 4.13
Natural capital: changes in the earth’s biodiversity over geological time. The biological diversity of life on land and in the oceans has increased dramatically over the last 3.5 billion years, especially during the past 250 million years. During the last 1.8 million years this increase has leveled off.
Millions of years ago
Fig. 4-13, p. 94

9. Predicting extinctions is always difficult because of three factors.
Extinction usually takes a long time and is difficult to document/prove.
A small percentage of the world’s species have even been identified.
We know very little about most of the world’s identified species

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

11. RED LIST
SHOW
WEBLINK

12. Various methods are used to estimate extinction rates
The World Conservation Union as kept Red Lists that are the world standard for listing all threatened species throughout the world.
“Half of mammals 'in decline', says extinction Red List” Oct 6, 2008
Nearly 40 percent of 44,838 species catalogued are listed as "threatened" with extinction, with 3,000 of them classified as "critically endangered,"
Species-area relationship is defined by the number of species’ increasing as the size of an area increases
Show red list link

13. When an area decreases by 90%, about 50% of the species there become extinct
Use models to estimate a species extinction risk by predicting population size, habitat changes/availability, and species interaction
Estimates of future extinction vary due to different assumptions

14. SPECIES EXTINCTION
Show them link for fish to avoid.
Percentage of various species types threatened with premature extinction from human activities.
Figure 11-5

15. SPECIES EXTINCTION
Scientists use models to estimate the risk of particular species becoming extinct or endangered.
Figure 11-6

16. Using estimated extinction rates, 20% of the world’s present plant and animal species will be gone by 2030; 50% would vanish by 2099.
Greater extinction rates than predicted are likely because of several factors
Species loss and biodiversity loss will likely increase because of exponential population growth
Biologically diverse areas (hot spots) rate of extinction may be as high as 25-50%

17. Possible colonization sites for new species are being eliminated, degraded and simplified by human activities so that new species cannot arise
Such a crisis may contribute to dominance of the world by species with survival power—cockroaches, rats and weeds!!

18. IMPORTANCE OF WILD SPECIES
We should not cause the premature extinction of species because of the economic and ecological services they provide.
It will take 5 million years for speciation to rebuild the animals and plants we will destroy in 100 years.
Medicinal properties are found in many plants and some animals
A male lion skin is worth $1,000; a male lion living for 7 years produces $515,000
Bats, often targeted for destruction by man, feed on crop-damaging insects, and pollinate flowers

19. Some believe that each wild species has an inherent right to exist.
Some people distinguish between the survival rights among various types of species (plants vs. animals).