Transcript Conclusion

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Conclusion
• Be sure you have clear justifiable objectives
for control….not just because you think it will
work!
• Be sure you have data on collateral effects
from control efforts
• Be aware that you are embarking on a long
term commitment.
• DON’T enter into it lightly!!
Ok, it is justified
• How do you do it?
• First is by manipulating mortality: killing them!
• Humane considerations need to be taken into
account (often difficult to do). Even the most
obviously deleterious species will have
defenders.
• The worse thing to do is make a sport of it!
Your set to kill
• What should be the appropriate control
strategy?
• Return to harvest strategies: the one that was
most prone to overharvest?
• Fixed quota harvest!
• Saw earlier that even if you have a stable
population, can remove enough to cause
overharvesting.
That is what you want!
• You want to exceed the maximum sustained
yield!
• Add to that the instability of populations, a
fixed quota harvest, set to overharvest would
provide the maximum control and could even
cause the population to go extinct.
Again, trick is how many
• Because you can overharvest anywhere on the
curve, setting the target kill then affects the
time it takes to reach eradication.
Examples
• Setting the kill rate of feral goats in a New
Zealand park at 90%, each year would lead to
eradication in 12 years.
• If it was only 50% it would take 50 years!
Other factors?
• Again, easy to say we will kill certain number
of animals/year but… as mentioned, the less
there are, the harder they are to get!
• Adjust to hunting pressure
• Adjust habitat to hard to get to places,
• Adjust behavior: cows in Mexico.
• Judas goats
Besides hunting them?
• Poisons!
• Whole storehouse of chemical poisons have been used
on “pest” species.
• Most famous:
• 1) Warfarin on rodents, blood thinner, literally bleed to
death.
• Strychnine: used on wolves, coyotes, and anything else
that eat carrion.
• 1080: Sodium fluoroacetate is an organic compound
and an organofluorine compound that is a well known
metabolic poison. Tasteless and odorless, perfect!
• M-44 or Coyote getter: exploding device that
expels cyanide into the mouth of the animal
that bites it.
• Many others
Historic use
• Used indiscriminately, spread over 1,000s of
km sq.
• Helped exterminate the wolf in the west.
• Not so effective on coyotes!
• Along with reducing populations of hundreds
of other species!
• Many are persistent and animal that dies from
them will kill others that eat on them!
Current use
• Much more controlled, many banned
• Still use M-44s for “target” operations
• Needless to say more environmental problems
related to their use than any benefits.
Besides hunting or poisoning them?
• Biological controls
• Effective against insects but less so against
vertebrate wildlife.
• Showcase is Myxoma against rabbits in
Australia.
• Still not 100 %, rabbits developed immunity
and Myxoma reduced virulence (not
evolutionarily advantageous to kill ALL your
hosts! About 20% of previous highs.
Other forms?
• So finding a biological agent is not so great
but…
• If you can’t augment mortality, try the other
end and reduce natality!
• Controlling fertility
• One way is to introduce sterile males!
• Screwworms in southeast US.
Flood the market!
• Flood the market with sterile males and
females (if they only mate once) will not be
successfully inseminated.
• Again, useful for insects but more problematic
for vertebrate pests!
• Unless you can sterilize them at a distance,
e.g. chemicals OR use contraceptives.
But… can they be effective?
• List of 17 characteristics of an ideal
chemosterilant program for rodents!
• Highlights
• Orally effective and at low doses
• Permanent or long-lasting and effective both
sexes
• At least genus specific and inexpensive
• Highly palatable and biodegradable
More!
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No acquired tolerance or genetic resistance!
Humane: no stressful symptoms
Sufficiently stable
NOT translocated into plants, especially
crops!!
• Is it possible???
• Do we want to go this route???
Is it possible?
• A lot depends on breeding systems of species.
• Usually will not be controlled by action against
only males.
• If breeding by dominant female suppresses
subordinate females, sterilization programs
could actually INCREASE productivity unless
you sterilize a sufficient number.
• Even without breeding system considerations,
often reduced litter production can result in
increased fertility of the females that are not
sterilized or receive the contraceptive!
• In rabbits in Australia, female sterility had to
reach 80% or more for a decline to occur!
• Last note: again, long term commitment
unless you can cause extinction!
Others?
• Immunocontraception
• Causing an increase in antibodies that hinder
reproductive processes.
• Has been used in elephants, horses, whitetailed deer, and seals.
• Must be injected and often more than once in
less than one year, and repeated yearly!
Effectiveness?
• Obviously only on small populations that are
easy to catch!
• Other: genetic engineering!
• Tie a gene that can disrupt reproduction to a
low virulent virus (e.g. Myxoma for rabbits).
• Problems with this!!!
Other than killing them or reducing
reproduction?
• Indirect methods:
• 1)Exclusions: fences (Farmer Brown and Peter
Rabbit!), chemical repellents
• Can be small scale or large: Australia built a
dingo proof fence spanning 8614 km!!
• Keeps out other species too!!
• Environmental costs high.
More?
• Sonic deterrents: alarm calls, ultrasonic sounds,
etc
- Unfortunately, not very effective
• Habitat and food manipulation
- found could reduce red squirrel damage on young
pines by air dropping sun flower seeds!
- Other examples: some have been effective, others
not so. Mixed results.
Summary
• Control operations rarely meet the necessary
criteria
• 1) when benefits exceed the costs
• 2) when “pest” species is in fact the cause of
the perceived problem
• 3) when control has an acceptable impact on
non-target species.
Summary
• Most clearly justifiable for exotic species
• Less so for natives: Often are not pests in that
there are a lot of them, perceived as such
because using a resource we want.
• Should we be disrupting ecosystem structure:
reducing predators, or medium to small
mammals .
Summary
• Control methods far from species specific and
usually a lot of collateral damage is done.
• Lastly…
• Considering managing and controlling wildlife
species we have to ask ourselves….
Is this the way it should be?
• If all we want is to “ranch” a single species, ok.
• Lets manage them like cattle and control their
predators/competitors
• But is that all we want?
• Is that what is good for the ecosystems that
support these desired species?
What should our management goals
be?
• Sacrificing keystone species and ecosystem
health for one single focused use of the
ecosystem.
• Remember it is the intact ecosystem that best
supports the species we desire: Alaska/Africa
• Not saying we should discontinue hunting, just
that it should not be the only focus in
resource management.
here
Original views
• America has always used the utilization of
natural resources, in this case wildlife, as the
focus of its resource management
• But is one species management the only
vision America had?
Remember
• Started with a point in time: concern about
our wildlife resources, theoretically could
have gone in an infinite number of different
directions.
• What other directions were there??
• Return to history
Return to the past
• Said concern started with Massive abuses of
natural resources
• Concern grew from this and led to 3 different
perspectives on how to manage resources.
A look at the past
• Resource Conservation Ethic.
- resources to be used but just need to control
the use.
• Romantic Transcendental Conservation Ethic
- Nature has other uses than just economic gain.
- Advocated protection of large pristine areas
A look at the past
• Evolutionary-ecological land ethic
- based on ecological awareness
- Nature more than collection of parts
- cannot discard some based on usefulness
- Also, not a temple to be worshipped
A look at the past
• Evolutionary-ecological land ethic
-Complicated, interconnected, functional
- result of long term evolutionary change
- We can use the system but not alter basic
structure
A look at the past
• Which of the three dominated?
• Resource conservation ethic most attuned
with growing country and economy.
• No Brainer!!
• This is what we have been talking about.
• Still believe nature was to be used, just not
abused, sort of….
A look at the past
• Tried to use what we wanted wisely
• Still discarded what we did not want or need.
• Time when we eliminated wolves from lower
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• “range management” use for cows
A look at the past
• Extraction not only function of ecosystems
• Other aesthetic, non extracting recreational,
supportive roles.
• We needed clean water, air, recreational
areas, open spaces, wilderness.
• Survival depended on functioning ecosystems.
A look at the past
• This awakening a mixture of the two ethics:
• Romantic-conservation- save for inherent
value
Evolutionary-ecological – we need all the parts!
A look at the past
• Started talking about ecosystem integrity,
biodiversity, keystone species, etc.
• Saw natural systems as dynamic entities
where change essential part of system
• Changed from managing elements of the
system to managing processes.
-fire management rather than fire suppression.
Today
• All the past laid the foundation for the next
logical step:
• Ecosystem Management as
opposed to resource
management
Ecosystem management
• What is it
• Not as easy as it may seem. Books give no less
than 14 definitions!!!
• Here are some of them.
“Ecosystem management is not just about
science nor is it simply an extension of
traditional resource management; it offers a
fundamental reframing of how humans may
work with nature”
Ecosystem management integrates scientific
knowledge of ecological relationships within a
complex sociopolitical and values framework
toward the general goal of protecting native
ecosystem integrity over the long term
R. E. Grumbine
Ecosystem approach = promoting ecological
integrity while allowing human use on a
sustainable basis
S. L. Yaffee
Ecosystem management is a concept of
natural resources management wherein
national forest activities are considered within
the context of economic, ecological, and
social interactions within a defined area or
region over both short and long term
An Assessment of Forest Ecosystem Health in the Southwest
Another
• Approach to maintaining or restoring the
composition, structure, and function of natural and
modified ecosystems for long term sustainability
• Based on Collaboratively developed vision of the
desired future conditions, integrating ecological,
socioeconomic , and institutional perspectives
• Applied in geographical framework defined by
natural ecological boundaries.
Common factors
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Large scale
System wide perspectives
Emphasis on composition and processes
Integration across various spatial temporal
scales
• Participation of stakeholders/consensus
decision making.
Dominant Themes in
Ecosystem Management
• Hierarchical context
• Recognition of
ecological boundaries
• Ecological integrity
• Research and
data collection
• Monitoring
• Adaptive
management
• Interagency cooperation
• Organizational change
• Humans as ecosystem
components
• Goals set by
human values
What are these things?
• These are the “parts” necessary for an
ecosystem management plan.
• Structural framework, not just definition but a
visual image of what it is.
• But what are its goals?
Fundamental Goals of
Ecosystem Management
• To mange ecosystems so as to
assure sustainability
• To maintain ecological integrity of the
system (i.e., healthy ecosystems)
Sustainability
• Maintenance of the potential of
ecosystems to produce the same
quantity and quality of goods and
services in perpetuity
Ecosystem Goods and Services
Ecosystem “goods”
• Food
• Construction materials
• Medicinal plants
• Wild genes for domestic plants and animals
• Tourism and recreation
Ecosystem
Services
• Maintaining hydrological cycles
• Regulating climate
• Cleansing water and air
•Pollinating crops and other impt. plants
• Generating and maintaining soils
• Storing and cycling essential nutrients
• Absorbing and detoxifying pollutants
• Provide beauty, inspiration and research
Guiding Principles for
Sustainability
Must maintain the physical and biological
elements of productivity including:
1. No net loss of productivity
2. No accelerate loss of genetic potential
Fundamental Goals of
Ecosystem Management
• To mange ecosystems so as to assure
sustainability
• To maintain ecological integrity of
the system (i.e., healthy ecosystems)
How to Maintain
Ecological Integrity
• Maintain viable populations
• Ecosystem representation
• Maintain ecological processes
• Protect evolutionary potential
• Accommodate human use
Terminology
• Resilience
• Biotic Integrity
• Adaptive Management
• Disturbance
• Indicators
How do we do it?
• Integration of ecological understanding and
socioeconomic perspectives and values
• Attempt to reconcile human interests and
needs with natural resource protection.
Conflict common!
•
Resolution requires perspectives from:
1) Ecologists
2) Diverse interest groups
3) Government agencies.
Three components
• Ecological.
• Socioeconomic.
• Institutional.
Three arenas in which we need to work.
Three Contexts
• Different view points
• Different possession of fact.
• Different capacities to pursue or prohibit
actions.
Three context model
• Core of ecosystem management structure
• Simple obvious solutions not universal
• Challenge to blend perspectives.
Visual conception
• Circles representing each
• Overlap in 4 areas. A, B,C,D.
• Gives us idea of how each
interact.
Zone A: Regulatory authority
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Ecologists feed info to agencies
Policy made based on info.
Legal right to do so.
Typical structure in past.
Zone B: social obligations.
• Socioeconomic and Institutional.
• No ecology
• Socioeconomic responsibilities
of agencies.
- Equal opportunities, etc.
Zone C: Zone of influence.
• People via groups influence
• Informal, interpersonal
relationships
• Trout Unlimited, Nature
Conservancy.
• Voluntary, private lands.
Ecosystem management stresses
-Partnerships of all stake holders
-Conflict low if knowledge high
-Conflict high if knowledge low.
-Adaptive management.
• So, need considerations on various levels
here
• Last three lectures on three different
considerations of ecosystem management
• 1) biological: populations
• 2) institutional: adaptive management
• 3) society: the human dimension