Title: How many animals do we need to save?
1How many animals do we need to save?
2How Many Animals Do We Want to Save? The Many
Ways of Setting Population Target Levels for
Conservation ERIC W. SANDERSON November 2006 /
Vol. 56 No. 11 BioScience 911
3A population of a few individuals cannot survive
ExtinctionVortex
4Can a number of individuals be set?
5Can a number of individuals be set? Fewest
number of individuals for an area, but fewest
number for what?
6- Can a number of individuals be set?
- Extreme examples
- Ecotourism want the largest possible population
- Mining or Agriculture would like none or
somewhere elseNIMBY
7- What are the consequences of setting the wrong
number? - Too high
- Too low
8- Can a number of individuals be set?
- Scientists are reluctant to set a specific number
- Policymakers want information from scientists
9What are the consequences of setting the wrong
number? Subjective values meets objective science
10How many wolves should be in Yellowstone NP
Yellowstone area wolf packs 2004
http//www.forwolves.org/ralph/historical.html
11How many tigers does the world need? None?
12- What criteria do we use to set limits?
- Money
- Land
- Development
13- What criteria do we use to set limits?
- Money
- Land
- Development
- Who benefits?
- Animals- what is the minimum number for
sustainable survival
14- What criteria do we use to set limits?
- Money
- Land
- Development
- Who benefits?
- Animals- what is the minimum number for
sustainable survival - Ecosystem- What is the minimum number to maintain
a healthy ecosystem?
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16- What criteria do we use to set limits?
- Money
- Land
- Development
- Who benefits?
- Animals- what is the minimum number for
sustainable survival - Ecosystem- What is the minimum number to maintain
a healthy ecosystem? - Humans- How many do we need to derive some
beneifit?
17- Who benefits?
- Animals- what is the minimum number for
sustainable survival? - Genetic Diversity
18- Who benefits?
- Ecosystem- What is the minimum number to maintain
a healthy ecosystem? - Density may be more important than total number
19- Who benefits?
- Ecosystem- What is the minimum number to maintain
a healthy ecosystem? - Density may be more important than total number
- Manage population and monitor effects on ecosystem
20- Who benefits?
- Ecosystem- What is the minimum number to maintain
a healthy ecosystem? - Density may be more important than total number
- Manage population and monitor effects on
ecosystem - Some species may be used to monitor health of
overall ecosystem
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22- Who benefits?
- Humans- How many do we need to derive some
beneifit? - Total eradication may be goal- mosquitos
23- Who benefits?
- Humans- How many do we need to derive some
beneifit? - Total eradication may be goal- mosquitos
- Ecotourism/Tourism
24- Who benefits?
- Humans- How many do we need to derive some
beneifit? - Total eradication may be goal- mosquitos
- Ecotourism/Tourism
- Harvest sustainable population
25- Who benefits?
- Humans- How many do we need to derive some
beneifit? - Total eradication may be goal- mosquitos
- Ecotourism/Tourism
- Harvest sustainable population
- Ecosystem benefits- seed dispersal, pollinators,
nutrient recycling
26- Who benefits?
- Humans- How many do we need to derive some
beneifit? - Total eradication may be goal- mosquitos
- Ecotourism/Tourism
- Harvest sustainable population
- Ecosystem benefits- seed dispersal, pollinators,
nutrient recycling - These functions cannot practically or
economically be carried out by humans
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28- Who benefits?
- Humans- How many do we need to derive some
beneifit? - Total eradication may be goal- mosquitos
- Ecotourism/Tourism
- Harvest sustainable population
- Ecosystem benefits
- Cultural, Aesthetic, Spiritual
29How many animals do we want to save?
30How many animals do we want to save? Complex
interactions of science, economics, and ethics.
31How many animals do we want to save? Complex
interactions of science, economics, and
ethics. If a number is set, it may stay static
as conditions change.
32How many animals do we want to save? Sandersons
proposed solution
33How many animals do we want to save? Sandersons
proposed solution Minimum Viable Population-
number of individuals that allows animals to
exist free from human interference.
34How many animals do we want to save? Most of
human history includes critical and profound
interactions with other organisms. That is now
diminished or gone.
35How many animals do we want to save? Most of
human history includes critical and profound
interactions with other organisms. That is now
diminished or gone.
36- How many animals do we want to save?
- Sandersons proposed solution- multilayered
approach - Demographic sustainability
37- How many animals do we want to save?
- Sandersons proposed solution- multilayered
approach - Demographic Sustainability
- Ecological Functions (includes ability to freely
evolve)
38- How many animals do we want to save?
- Sandersons proposed solution- multilayered
approach - Demographic Sustainability
- Ecological Functions
- Human Use and Interactions
39- How many animals do we want to save?
- Sandersons proposed solution- multilayered
approach - Demographic Sustainability
- Ecological Functions
- Human Use and Interactions
- Can we return animals to levels that existed
before humans had a negative impact?
40- Instead of a single numberA number for each
level can be determined. - How many animals do we want to save?
- Demographic Sustainability
- Ecological Functions
- Human Use and Interactions
- Can we return animals to levels that existed
before humans had a negative impact?
41How many animals do we need to save?
42Skills needed for the exams
http//wisdomquarterly.blogspot.com/2008/07/painfu
l-facts-dukkha.html
43Skills needed for the exams
1. Understand material from lecture. Quizzes
can help diagnose. Be self-critical and
skeptical.
http//wisdomquarterly.blogspot.com/2008/07/painfu
l-facts-dukkha.html
44Skills needed for the exams
1. Understand material from lecture. 2. Be
able to apply the information. http//www.youtube
.com/watch?vlDbSbOsoRnY
45Skills needed for the exams
2. Be able to apply the information. Lecture is
presented linearly, but applying the information
may mean seeing it non-linearly.
http//wisdomquarterly.blogspot.com/2008/07/painfu
l-facts-dukkha.html
46Skills needed for the exams
3. Communicate what you know. If I answered
your question with what you wrote down, would it
make sense?
http//wisdomquarterly.blogspot.com/2008/07/painfu
l-facts-dukkha.html
47Skills needed for the exams
1. Understand material from lecture. 2. Be
able to apply the information. 3. Communicate
what you know.
http//www.mac-pac.org/temp/motivation.html