Wild Living resources: Plentiful and Endangered

1
Chapter 12

• Wild Living resources Plentiful and Endangered

2
Four Main Points

• Justifications for preservation
• Causes of Extinction
• Human Impacts
• Wildlife Management (solutions)

3
Four possible goals of wildlife conservation

• 1 - wild creature/wild habitat
• 2 - wild creature/managed habitat
• 3 - zoo
• 4 - genetic material

4
2 definitions

• Endangered - faces threats that could cause
  extinction in a short time
• Threatened - a decline in population causes
  concern about extinction

5
Who is most endangered?

• 1 - Insects
• 2 - Mollusks
• 3 - Fish
• 4 - birds
• 5 - Mammals

6
Justifications for saving species

• Utilitarian
• Ecological
• Aesthetic
• Moral

7
Utilitarian Justification

• Species are useful
• Genetic characteristics - useful in agriculture
• Chemical and medical uses
• New crops and products

8
Utilitarian (cont.)

• Indigenous peoples
• Pollution control
• Filter feeders and plants
• Tourism
• Medical research

9
Ecological Justification

• To keep the system running
• Keystone species may be important
• Forest Conservation
• Soil conservation and water control

10
Ecological (cont.)

• Global Perspective
• Bacteria, pollinators

11
Aesthetic/Cultural

• Beauty
• Traditions ie bald eagle

12
Moral Justification

• All species have right to exist
• Formalized in the UN charter for nature in 1982
  and the Endangered species act

13
Extinction!!!!!

• From 580 million ybp to industrial rev rate was 1
  per year
• Has accelerated since then, see graph page 239.

14
Extinction

• There have been many mass extinctions in
  history (see page 235
• These generally coincide with catastrophic/climati
  c events

15
Extinctions

• More recent mass extinctions coincide with
  arrival of humans on land masses

16
Causes of extinction

• Population risk
• Low numbers can decrease chance of mating
• Environmental Risk
• Changes in surroundings effect survival

17
Causes of extinction

• Natural Catastrophe
• Fire, volcano, hurricane
• Genetic Risk
• Genetic drift, probability of accumulation of
  detrimental genes

18
Common Traits of Endangerment

• Long lived and large
• Low repro rates, slow recovery
• Specialist species
• Not adaptable to changes

19
How people cause extinction

• Intentional hunting
• Habitat destruction/disruption
• Introduced species
• pollution

20
Wildlife management

• renewable - can be regrown
• MSY v OSY
• Sustainiblity of a species v. of its ecosystem

21
Logistic growth and MSY

• See graph on pg 243
• If population is harvested at the inflection
  point msy sustains the population level
• This is not a very reliable system

22
4 principles

• A safety factor
• Concern for the community level
• Maintain the ecosystem
• Monitoring and analysis

23
Wildlife management techniques

• May set limit on age sex or size of individuals
  killed
• May manipulate habitat and ecosystem
• Need to know pop size, growth, other mortality,
  carrying cap, natural variation

24
What is being done?

• Emergency actions
• STOP HARVESTING!

25
What is being done?

• Minimum viable population size
• The 50/500 rule
• 50 breeding adults avoids genetic problems
  (inbreeding)
• 500 avoids problems of low variability (response)

26
What is being done?

• Ecological Islands
• All parks are some form of ecological island
• Size must be considered

27
What is being done?

• Exotic species as a solution
• Ex. Dung beetles introduced to offset the effect
  of a previously introduced species, cattle

28
What is being done?

• Long term planning
• Linkages between facilities
• Zoos, hospitals, parks,
• Can help with genetic diversity

29
The endangered species act

• Unlawful selling, importation, exportation, of
  E. species or products
• Illegal harass, harm or capture,
• Protects habitat