1. Chapter 12

2. Extinctions
Local- species is no longer found in an area it once inhabited
Ecological- numbers of species are so few that it can no longer play its ecological roles in biological communities
Biological- species is no longer found anywhere on Earth (forever)

3. Endangered VS. Threatened
Endangered- so few individual survivors that species could become extinct
Threatened- abundant in natural range but declining numbers & likely to become endangered

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

5. Extinction Rates 0.1 to 1% per year
1,000 to 10,000 times higher than prior to humans

6. Rates
Rate of species loss & the extent of biodiversity loss are likely to increase in next years due to human population growth
Current & projected extinction rates are much higher than global average in endangered centers of biodiversity
Humans are eliminating degrading & simplifying many biologically diverse environments

7. Why?
It will take at least 5 million years for speciation to rebuild the biodiversity we are likely to destroy during this century.
Intrinsic value- (existence) inherent right to exist & play its ecological role regardless of its usefulness to us
Biophilia- love of life

8. Causes of Reduction of populations
Habitat
loss
Overfishing
Pollution
Habitat degradation
and fragmentation
Commercial
hunting and poaching
Climate change
Introducing
nonnative species
Sale of exotic pets
and decorative plants
Predator and pest control
Secondary Causes
Population growth
Rising resource use
No environmental
accounting
Poverty
Basic Causes
Causes of Reduction of populations

9. Premature Extinctions
Habitat disturbance – agriculture, commercial development, water development, outdoor recreation, livestock grazing, pollution
Indian tiger, Black rhino, African & Asian/Indian elephant

10. Habitat fragmentation - large, continuous area of habitat is reduced in area & divided into small scattered, isolated spots
(Deliberate) Nonnative species- used as biological control; no natural predators, competitors, parasites, or pathogens to help controls numbers; wipe out native species, disrupt ecosystems & cause large economic losses

11. Accidentally introduced Species
Figure 12-9b Page 235
Sea lamprey
(attached to lake trout)
Argentina fire ant
Brown tree snake
Eurasian muffle
Common pigeon
(Rock dove)
Formosan termite
Zebra mussel
Asian long-horned
beetle
Asian tiger mosquito
Gypsy moth larvae
Accidentally introduced Species

12. (Accidental) Nonnative species- arrive as stowaways on aircraft, tankers, cargo ships; no natural predators allow rapid spreading
Poaching- killed for valuable parts or sold to collectors; increases chances of premature extinction
Mountain gorilla (live), panda pelt, chimpanzee, Imperial Amazon macaw, rhinoceros horn

13. Deliberately introduced Species
Figure 12-9a Page 235
Purple looselife
European starling
African honeybee
(“Killer bee”)
Nutria
Salt cedar
(Tamarisk)
Marine toad
Water hyacinth
Japanese beetle
Hydrilla
European wild boar
(Feral pig)
Deliberately introduced Species

14. Exotic & decorative- profitable
Predator & pest control- people exterminate species that compete with them for food & game animals
Elephants, prairie dogs, wolves, bobcats, coyotes
Exotic & decorative- profitable
Exotic birds (macaw), amphibians, reptiles, mammals, tropical fish
Climate change & pollution- human activities bring a rapid climate change
Polar habitats
Pesticides- honey bees, birds, fish

15. Birds Decline in population – 70%
1 in 6 bird species – threatened with extinction
Environmental Condition Indicator
Live in every climate & biome
Respond quickly to environmental changes to habitats
Easy to track & count

16. Ecosystems Vulnerable
Characteristics of
Successful
Invader Species
Characteristics of
Ecosystems Vulnerable
to Invader Species
High reproductive rate, short generation time (r-selected species)
Pioneer species
Long lived
High dispersal rate
Release growth- inhibiting chemicals into soil
Generalists
High genetic variability
Similar climate to habitat of invader
Absence of predators on invading species
Early successional systems
Low diversity of native species
Absence of fire
Disturbed by human activities
Figure Page 238

17. Reducing the Threat
Identify characteristics that allow species to become successful invaders & vulnerable ecosystems
Inspect imported goods that may contain invaders
Identify harmful invader species & pass laws banning transfer
Prevention & control

18. CITES Convention on International Trade in Endangered Species
Restrictions on species that cannot be traded or sold (over 30,000 species)
Difficult to enforce
Enforcement varies from country to country
Highly profitable trade occurs in countries that did not sign treaty

19. ESA Endangered Species Act
Designed to identify & legally protect endangered species in US & abroad
Americans cannot sell or buy products made from these animals

20. HCPs Habitat Conservation Plans
Landowners, developers, loggers allowed to destroy part of endangered or threatened species population on private land in exchange for taking steps to protect the species

21. Safe Harbor Agreements
Landowners voluntarily agree to take specified steps to restore, improve, or maintain habitat for threatened or endangered species located on their land

22. Voluntary Candidate Conservation Agreements
Landowners agree to take steps to help conserve a species whose population is declining
***All 3 are designed to be a compromise between private landowners & interest of endangered & threatened species

23. Landowner Compensation
Advantages-
Disadvantages- cost, hinders passage of new land use, environmental, health, & safety laws

24. ESA Expensive failure Only 37 species have been removed from this list
14 recovered
8 extinctions
Others removed due to technical errors or discovery of new populations

25. Wildlife Refuge
Serve as a vital wetland sanctuary for migratory waterfowl
Some set aside for specific endangered species
Bad news- 60% of activities that are harmful to wildlife occur within refuges; invasions by nonnative species; too much hunting/fishing & use of powerboats & off-road vehicles cause damage

26. Gene Bank
Preserves genetic info & endangered plant species by storing seeds in refrigerated, low-humidity environment; store wide range of threatened species & genetic diversity
Bad news- expensive to operate; destroyed by accidents; prevents evolution

27. Botanical Gardens Arboretums
Contain living plants; educates million of visitors
Bad news- too little capacity; too little funding

28. Zoos
Used to preserve some individuals of critically endangered species with long-term goal of reintroducing the species into protected wild habitats
Egg pulling- collecting wild eggs laid by critically endangered bird species & hatch in zoos or research centers
Captive breeding- wild individuals are captured for breeding with aim of reintroducing offspring into the wild

29. Bad news- lack of space & money; major role needs to be education

30. Aquarium
Exhibits unusual & attractive fish & marine animals; education to public about need for protection; not an effective gene bank
Bad news- considered a prison; fosters the false notion that preserving small numbers is useful

31. Reconciliation Ecology
Science of inventing, establishing, & maintaining new habitats to conserve species diversity in places where people live, work, play
Examples
Butterfly habitat- 20+ neighbors provide self-sustaining habitat would attract birds or bat-eating insects
Safe harbor agreements- bluebirds- nest boxes