Transcript Changing Limiting Factors

Conservation Challenges
• “Habitat” Effects
– Land cover change
• Urbanization
• Agriculture
– Land use
• Natural resources
– Forestry
– Fishing
– Energy
• Recreation
• Communication
– Cell towers
• “Habitat”-Independent
Effects
– Stewarding, Reserving, and
Restoring Habitat are
necessary, but NOT
SUFFICIENT
•
•
•
•
•
Exotic Species
Disease
Overharvest
Climate Change
Pollution
Conservation Challenges
• “Habitat” Effects
– Land cover change
å
Urbanization
• Agriculture
– Land use
• Natural resources
å
•
√
– Forestry
– Fishing
– Energy
Recreation
Communication
– Cell towers
• “Habitat”-Independent
Effects
– Stewarding, Reserving, and
Restoring Habitat are
necessary, but NOT
SUFFICIENT
√
√
√
•
•
•
•
•
Exotic Species
Disease
Overharvest
Climate Change
Pollution
Agriculture
• Global changes:17001990 (Meyer and Turner 1992)
(Lambin et al. 2001)
–
–
–
–
–
–
–
–
Cropland
+392 - 466%
Irrigated Cropland
+2400%
Closed Forest
-15.1%
Forest and woodland -14.9%
Grassland/pasture -1%
Lands drained
1.6 x 106 km2
Urban settlement 2.5 x 106 km2
Rural settlement 2.1 x 106 km2
All Species
Farmland Specialists
An
Example
From
Czech
Republic
(Reif et al. 2008)
Generalists
Bird Declines
continued despite
reduction in
Agricultural Intensity
after fall of
communism
Continued decline
could be due to:
1. Factors other than
Ag
2. Lag effect
3. Cumulative effect of
loss of farm area
4. Abandonment of
farms
Improving Agriculture for Birds
• Intensification
generally reduces
bird diversity
• Set asides help
(CRP lands, field
borders, no till)
• Herkert 2009
Fishing and Seabirds
• Eiders and cockles
• We hypothesize that the population of common eiders
collapsed as a result of a combination of factors:
heavy fishing pressure on high density cockle banks
and rather low stocks in mussel cultures over the past
10 years (Camphuysen et al. 2002)
Spotted Owl Declines in Washington
(Forsman et al. unpublished)
Exotic Species
(Livezey 2009)
(Livezey 2009)
Disease
Example from California (Wheeler et al. 2009)
180
Pre-La Niña (1996-1998)
La Niña (1998-1999)
Post-La Niña (1999-2000)
Winter precipitation (cm)
160
140
120
100
80
60
40
20
0
Quillayute
(Pacific Coast)
Seattle
Washington State
Mean
Quillayute (Pacific
Coast)
Seattle
Washington State
Mean
Cold Water
Mean spring temperature (°C)
12
10
8
6
4
2
0
Weather Station
Pre La Niña (1995-98 average)
Post La Niña (1999)
Mean number detected per
10 minute point count (50m radius)
0.8
0.7
Local Effects on
Goshawk Prey
0.6
0.5
0.4
0.3
0.2
0.1
0
Douglas' Squirrel
Number harvested per hunter-day
0.6
Gray Jay
Steller's Jay
Pre La Niña (1994-98 average)
Post La Niña (1999)
Post La Niña (2000)
0.5
0.4
0.3
0.2
0.1
0
Gr o u se ( b l u e a n d r u f f e d c o m b i n e d )
(Bloxton et al.)
When prey decline, hawks have to move more
10000
95% Fixed Kernel (Ha)
8000
6000
4000
2000
0
Pre La Niña
Post La Niña
Lack of prey and increased
movement lead to lower
reproduction and survivorship
Upper 95% CI
Survival
1.6
1.4
0.8
1.2
1
Survival
Mean number young fledged per occupied
territory
1.0
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
Pre La Niña
Post La Niña
0.0
Lower 95% CI
Climate Change
European Migrants
1970 – 1990: big birds
and those not in ag
areas had best
population trends
1990 – 2000: change in
migration date most
important, habitat
specialization also
associated with declining
populations
(Møller et al. 2008)
Adapt or Go Extinct
What to Do?
• Birds are smart
• Birds are mobile
• Birds can evolve
rapidly
• But when
population size is
greatly reduced,
extinction happens
• Keep population
size (effective
population size)
large, so innovation
and adaptation can
continue to occur
Conservation Manifesto
•
•
•
•
•
Active Management to Reduce Limiting Factors
Reservation
Restoration
Reconciliation
Sustainable Concern
– Engage people to adopt a land ethic generally and
bird ethic specifically
• Conservation is getting nowhere because it is incompatible
with our Abrahamic concept of land. We abuse land because
we regard it as a commodity belonging to us. That land is a
community is the basic concept of ecology, but that land is to
be loved and respected is an extension of ethics.
(Leopold 1948)
A Bird Friendly Morality
Thou shall not covet thy neighbor’s lawn.
Thou shall not allow thy cat to roam.
Thou shall make thy windows visible.
Thou shall not light the night sky.
Thou shall provide food and nest boxes.
Thou shall not kill native predators.
Thou shall abhor uniformity.
Thou shall provide safe passage across thy
roadways.
9. Thou shall provide functional connections between
terrestrial and aquatic worlds.
10. Thou shall nurture the human bond with nearby
nature.
1.
2.
3.
4.
5.
6.
7.
8.
References
• Camphuysen, C. J., et al. 2002. Mass mortality of common eiders in
the Dutch Wadden Sea, winter 1999/2000: starvation in a
commercially exploited wetland of international importance.
Biological Conservation 106:303-317.
• Herkert, J. R. 2009. Response of bird populations to farmland setaside programs. Conservation Biology 23:1036-1040.
• Livezey, K. B. 2009a. Range expansion of barred owls, part I:
Chronology and distribution. Am. Midl. Nat 161:49-56.
• Livezey, K. B. 2009b. Range expansion of barred owls, Part II:
Facilitating ecological changes. Am. Midl. Nat. 161:323-349.
• Reif, J. et al. 2008. Agricultural intensification and farmland birds:
new insights from a central European country. Ibis 150:596-605.
• Wheeler, S. S. et al. 2009. Differential impact of West Nile virus on
California birds. The Condor 111:1-20.