How many animals do we need to save?. How Many Animals Do We Want to Save? The Many Ways of Setting...

How many animals do we need to save?

How Many Animals Do We Want to Save? The Many Ways of Setting Population Target Levels for ConservationERIC W. SANDERSONNovember 2006 / Vol. 56 No. 11 BioScience 911

ExtinctionVortex

A population of a few individuals cannot survive

Can a number of individuals be set?


Fewest number of individuals for an area, but fewest number for what?


Extreme examples:

•Ecotourism want the largest possible population

•Mining or Agriculture would like none or somewhere else…NIMBY

What are the consequences of setting the wrong number?

•Too high

•Too low


•Scientists are reluctant to set a specific number

•Policymakers want information from scientists

What are the consequences of setting the wrong number?

Subjective values meets objective science

http://www.forwolves.org/ralph/historical.html

Yellowstone area wolf packs 2004

How many wolves should be in Yellowstone NP

How many tigers does the world need? None?

What criteria do we use to set limits?•Money•Land•Development


Who benefits?•Animals- what is the minimum number for sustainable survival


Who benefits?•Animals- what is the minimum number for sustainable survival•Ecosystem- What is the minimum number to maintain a healthy ecosystem?


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?

Who benefits?•Animals- what is the minimum number for sustainable survival?

Genetic Diversity

Who benefits?•Ecosystem- What is the minimum number to maintain a healthy ecosystem?

Density may be more important than total number


Density may be more important than total numberManage population and monitor effects on ecosystem


Density may be more important than total numberManage population and monitor effects on ecosystemSome species may be used to monitor health of overall ecosystem

Who benefits?•Humans- How many do we need to derive some beneifit?

Total eradication may be goal- mosquitos


Total eradication may be goal- mosquitosEcotourism/Tourism


Total eradication may be goal- mosquitosEcotourism/TourismHarvest sustainable population


Total eradication may be goal- mosquitosEcotourism/TourismHarvest sustainable populationEcosystem benefits- seed dispersal, pollinators, nutrient recycling


Total eradication may be goal- mosquitosEcotourism/TourismHarvest sustainable populationEcosystem benefits- seed dispersal, pollinators, nutrient recycling

These functions cannot practically or economically be carried out by humans


Total eradication may be goal- mosquitosEcotourism/TourismHarvest sustainable populationEcosystem benefitsCultural, Aesthetic, Spiritual

How many animals do we want to save?


Complex interactions of science, economics, and ethics.


Complex interactions of science, economics, and ethics.

If a number is set, it may stay static as conditions change.

How many animals do we want to save?Sanderson’s proposed solution:

How many animals do we want to save?Sanderson’s proposed solution:Minimum Viable Population- number of individuals that allows animals to exist free from human interference.


Most of human history includes critical and profound interactions with other organisms. That is now diminished or gone.

How many animals do we want to save?Sanderson’s proposed solution- multilayered

approach:1. Demographic sustainability


approach:

1. Demographic Sustainability

2. Ecological Functions (includes ability to

freely evolve)


approach:


2. Ecological Functions

3. Human Use and Interactions


approach:




4. Can we return animals to levels that existed

before humans had a negative impact?

Instead of a single number…A number for each level can be determined.





4. Can we return animals to levels that existed

before humans had a negative impact?

How many animals do we need to save?

http://wisdomquarterly.blogspot.com/2008/07/painful-facts-dukkha.html

Skills needed for the exams:


1. Understand material from lecture.

Quizzes can help diagnose.

Be self-critical and skeptical.



2. Be able to apply the information.http://www.youtube.com/watch?v=lDbSbOsoRnY


http://www.youtube.com/watch?v=lDbSbOsoRnY


2. Be able to apply the information.

Lecture is presented linearly, but applying the information may mean seeing it non-linearly.



3. Communicate what you know.

If I answered your question with what you wrote down, would it make sense?



2. Be able to apply the information.

3. Communicate what you know.


http://www.mac-pac.org/temp/motivation.html

How many animals do we need to save?. How Many Animals Do We Want to Save? The Many Ways of Setting...

Documents

Transcript of How many animals do we need to save?. How Many Animals Do We Want to Save? The Many Ways of Setting...