How Will Climate Change Affect Birds?
David Karowe
Department of Biological Sciences
Western Michigan University
Temperature Anomaly (oC)
Since 1900, Earth has warmed ~ 0.8o C
12 warmest years in history:
2002-2012, 1998*
*
Warming is 10-20 times faster than
in at least the last 800,000 years
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Temperature difference relative to 1950-1980
Precipitation is a very important component of climate
- severe rainstorms have become more common
40% increase in southwest Michigan since 1948
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1950-1959
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At the same time, much of the world has been
experiencing more frequent and stronger droughts
Palmer Drought Severity Index (PDSI)
At the same time, much of the world has been
experiencing more frequent and stronger droughts
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1950-1959
2000-2009
Palmer Drought Severity Index (PDSI)
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Climate predictions are coming true in the U.S.
In 2011, 10 states had their wettest spring on record
As a result, there was extensive flooding
4
2012 was the warmest year on record for the U.S.
Much of the U.S. has been experiencing severe drought
September 2012
77% drought
5
“Natural variation” cannot explain current warming
What causes “natural variation”?
Recently, while Earth has been warming fastest,
solar irradiance has been decreasing
Temperature
Solar Irradiance
6
In two major ways, current warming is
very different than any warming period
in at least the last 800,000 years
1. It’s at least 10-20 times faster
2. It’s happening while solar input is decreasing
Best estimate: ≥ 95% of current warming
is due to human activities
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How have birds responded to recent climate change?
1. Changes in geographic range
- latitudinal shifts, elevational shifts
2. Changes in seasonal timing (phenology)
- migration, nesting
Some U.S. birds are shifting their ranges north
From 1970-2000, 33% of 27
species with a southern
breeding distribution shifted
north
- average shift of 3.9 mi/yr
- but most species haven’t
shifted
Great-tailed Grackle
8.0 mi/yr
Blue-gray Gnatcatcher
7.5 mi/yr
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Winter ranges are also shifting north
For 254 U.S. species from 1975-2005, northern range
boundary shifted north by 0.84 mi/yr
- but, again, most
species haven’t
shifted
Northern Bobwhite
Long-billed Curlew
For some species, southern range is contracting
In New York state from 1980-2005, 22 northern species
lost part of their southern range
Pine Siskin
Bobolink
- but southern species did not expand
their northern range boundary
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Some species have shifted to higher elevations
From 1975-2000, 27% of 485 Southeast Asian species
expanded their ranges upward
Little Forktail
Russet Sparrow
- most did not shift their
lower range margin upward
In New York, only resident species have shifted to
higher elevations
Carolina Wren
Tufted Titmouse
- but mean elevational shift was only 50 feet in 25 years
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Are birds shifting their ranges fast enough?
- in France from 1989-2006,
bird communities shifted
north by 3.3 miles/year
- but climate shifted north
by 10.3 miles/year
In Peru, elevational shifts among 55 bird species
also appear to be lagging behind climate change
- probably constrained by rate of vegetation shifts
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Some species are showing phenological shifts
(changes in timing of life events)
e.g. on Cape Cod from 1970-2002, median date of migrants’
spring arrival shifted earlier for 8 of 32 passerines
- but 24 of 32 species have not shifted their arrival dates
3.6 days/dec
1.2 days
2.9 days
1.1 days
2.1 days
1.0 days
1.8 days
1.0 days
Some Canadian species are also arriving earlier
Of 96 migrant species, over a 63-year period,
25 significantly advanced their spring arrival dates
20 days earlier
15 days earlier
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In Pennsylvania, from 1961-2006, local breeders
shifted spring migration more than northern breeders
- but climate is
changing faster for
northern breeders
- and northern breeders
are migrating earlier
in the fall
General trend: short-distance migrants are tracking
climate change better than long-distance migrants
Some species are starting to lay eggs earlier
e.g. Italian Black Kites are laying eggs 10 days earlier
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Species that have been tracking climate change
have fared better than species that have not
- e.g. 100 European species since 1990
returning earlier, increasing
Stock Dove
returning later, decreasing
Black-throated Loon
This is also true among populations of a single species
- Dutch Pied Flycatcher populations with little advance
in egg laying date have declined by up to 90%
- probably due to
mismatched timing
with major food
resource (caterpillars)
- populations with much advance have declined by <10%
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How will our climate change in the future?
It depends on our choices
If we remain on our current course,
future climate change will be severe
Depending
on choices
we make,
Earth will
likely warm
by 2-5o C
by 2100
Actual
“Business
as usual”
Alternate energy
sources
5o
4o
2o
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Will a 5o temperature rise matter?
When Earth was 5o cooler:
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Much of the world is likely to experience much
more frequent and stronger droughts by the 2060s
2060-2069
1950-1959
2000-2009
Palmer Drought Severity Index (PDSI)
- current drought indices will no longer work
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Most summers are likely to be hotter than any
experienced thus far
Most summers are likely to be hotter than any
experienced thus far
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Many areas are also predicted to experience
“disappearing climates” by 2100
(current climate does not occur within 500 km)
Low
Moderate
High
Probability of disappearing climate
How will future climate change affect birds?
It depends on the choices we make
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Which species are particularly vulnerable?
1. Species that fail to track changing climates
- long-distance migrants
2. Species that live in the tropics
- disappearing climates
3. Species that have nowhere to go
In Antarctica, Emperor and Adelie penguins need ice
but Chinstrap and Gentoo penguins nest on land
19
Other high latitude species have nowhere to go
Scandinavian bird species
are predicted to lose 80%
of their suitable habitat by
2080
High elevation species also have nowhere to go
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All of Earth’s 1,009 montane bird species are
predicted to be “climate losers”
Climate change has the potential to cause a
massive extinction event among the world’s birds
~ 1,750
~ 900
~ 400
~ 125
~ 200
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And put many more species at risk of extinction
~ 2,450
~ 2,200
~ 2,150
~ 1,850
~ 1,950
Western Hemisphere birds could be similarly affected
22%
1%
27%
3%
32%
6%
38%
12%
52%
23%
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However, including vegetation in addition to temperature
and precipitation makes the predictions less dire
For 150 eastern U.S. species with 4o warming, many more
predicted “climate losers” than “climate winners”
Loss >25%
No change
Gain >25%
P e rc e n t o f S p e c ie s
90
80
70
60
50
40
30
20
27 36 9
20 20 3
Neotropical
Temperate
1
16
2
10
0
Resident
- resident species are predicted to be much less affected
than short-distance and long-distance migrants
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More climate losers than climate winners predicted
in all habitats except wetlands
Loss >25%
No change
Gain >25%
P e rc e n t o f S p e c ie s
70
7 1 11
60
50
40
30
20
24 20 9
4 6 1
14 9 5
Forest
Grassland
Shrubland
10
0
Wetland
What will climate change mean for Michigan species?
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At least 20 common tree species are predicted to
decline by 50-100% in Michigan, including:
-98%
black spruce
-89%
balsam fir
-97%
-89%
paper birch
aspen
-67%
-66%
sugar maple
eastern hemlock
20 southern species are predicted to arrive in Michigan
loblolly pine
sweetgum
shortleaf pine
Virginia pine
sugarberry
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As go the forests, so go the birds
50 Michigan bird species predicted to decline by 50-100%
Common loon
Evening
grosbeak
White-throated
sparrow
Red-breasted
nuthatch
Veery
Magnolia
warbler
Yellow-bellied
sapsucker
Blackburnian
warbler
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15 new species are predicted to arrive in Michigan
northern
bobwhite
Mississippi
kite
yellow-billed
cuckoo
scissor-tailed
flycatcher
little blue
heron
painted
bunting
cattle egret
summer
tanager
What can I do to minimize climate change?
We can change the future by implementing
multiple solutions that already are available
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Next time, buy a more fuel-efficient car
20 mpg
34 mpg
30 mpg
50 mpg
Weatherize your house: weather-strip, adequately
insulate attic, and replace single-pane windows
with triple-pane windows
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Unfortunately, energy conservation is not a solution
50 mpg
- really just delays the inevitable
To limit warming to 2o C, we need to reduce
greenhouse gas emissions by 80% by 2050
This can only happen through aggressive expansion
of alternate energy sources
Solar
Wind
Globally, we generate only 0.2% of our energy from wind,
and only 0.1% from solar
29
Global wind potential is >40 times worldwide use
All 9 highest CO2-emitting countries could use wind alone
183x
23x
183x
30x
8x
18x
3x
3x
8x
The “intermittency problem” can be solved easily
e.g. Luddington pumped storage plant
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Solar energy has even greater potential
Three main technologies:
solar thermal
parabolic trough
photovoltaics
Global potential estimated at up to 100 times current use
A small portion of the Sahara desert could supply all
of the world’s electricity
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A solar array 100 x 100 miles could provide all of US
energy needs today
Again, “intermittency problem” can be solved easily
solar thermal
parabolic trough
- store excess heat during day, generate electricity at night
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Educate others
Encourage policymakers to make smarter choices
MI 6th District voters will have a clear choice
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What would Earth gain by these smarter choices?
3.5o C
warming
Low
Moderate
High
Probability of disappearing climate
2o C
warming
Bottom Line:
1. We’re causing climate to change at an
alarming rate.
2. If we continue on our current path, the future
is very likely to include unprecedented
hardships for many bird species, especially
tropical and montane species.
3. We can change our path by making smarter
choices in our own lives and by electing leaders
who will also make smarter choices.
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Thank you for listening
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