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Small Mammal ModuleObjective: determine small mammal responses to forest
management practices, at local and landscape scales
Responses: demography, habitat associations, spatial distribution
Components:-Long term grids: 21 grids, 4 forest types, 4 treatment types
mammals, vegetation, cone production (in progress)
-Landscape transects: 74 transects (completed)mammals, vegetation
-Focal species: radiotelemetry & habitat measurementsNorthern flying squirrels (completed)Dusky-footed woodrats (completed)
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• 2009 accomplishments:
– 2 full samples of all treatment and habitat grids (n=21)– 823 individuals over 1,672 captures of 10 species
– full cone count sample
Long-Term Grids
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Overall Yearly Trends
Year
2003 2004 2005 2006 2007 2008 2009
Mea
n Ab
unda
nce
0
5
10
15
20deer micechipmunksflying squirrelswoodrats
Long-Term Grids
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Flying Squirrels
2005 2006 2007 2008 2009
Mea
n Ab
unda
nce
0
1
2
3
4
5
6
7
8
Woodrats
2003 2004 2005 2006 2007 2008 2009
0.0
0.5
1.0
1.5
2.0
2.5
Long-Term Grids
Habitat TypesDouglas FirPine - CedarRed FirWhite Fir
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Long-Term Grids
Habitat Types
Chipmunks
2003 2004 2005 2006 2007 2008 2009
Mea
n Ab
unda
nce
0
10
20
30
40
50
60
Deer Mice
2003 2004 2005 2006 2007 2008 20090
10
20
30
40
50Douglas FirPine - CedarRed FirWhite Fir
Douglas FirPine - CedarRed FirWhite Fir
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Flying Squirrels
2005 2006 2007 2008 2009
Mea
n Ab
unda
nce
0.0
0.5
1.0
1.5
2.0
Treatment
Long-Term Grids
Treatments
Woodrats
2003 2004 2005 2006 2007 2008 2009
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Treatment
ControlGroup-selectHeavy-thinLight-thin
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Chipmunks
2003 2004 2005 2006 2007 2008 2009
Mea
n Ab
unda
nce
0
5
10
15
20
Treatment
Deer Mice
2003 2004 2005 2006 2007 2008 2009
0
5
10
15
20Treatment
Long-Term Grids
TreatmentsControlGroup-selectHeavy-thinLight-thin
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Year
2003 2004 2005 2006 2007 2008 2009 20100
20
40
60
80
100 Mean Cone AbundanceAnnual Snow FallMean Mouse Abundance
?
Long-Term Grids
Mice over Time
• Copetto et al. 2006 documented that forest type and year explained 93% of yearly variation in deer mice on the same study grids (n = 18).
• Year is a surrogate measure that reflects:-Temporal variations in resource abundance (i.e., conifer cones).
&-Environmental factors such as precipitation.
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Year
2004 2005 2006 2007 2008 2009
Mea
n Ab
unda
nce
0
20
40
60
80observed mouse abundancepredicted mouse abundance
Y= (-0.41 * snow) + (0.32 * fir) + (0.20 * pine) + 40.24
Long-Term Grids
More on Mice
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2 34
5
1TU-3
Landscape TransectsMethods
50 m
35 m
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Landscape TransectsResults
• In 2009 we sampled 30 transects = 232 census stations across 4 treatment units, bringing our total sample to 74 transects = 599 census stations.
• 2,016 captures of 1,367 individuals of 11 species in 2009.
• 6,166 captures of 3,937 individuals of 13 species over 3 year sampling effort.
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Abundance:6.58 (+ 0.24) animals/census pt.
Treatment Unit #
2 3 4 5
Me
an
# o
f in
div
idu
als
/ce
ns
us
po
int
0
2
4
6
8
10
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Species richness:2.02 (+ 0.05) species/census pt
Treatment Unit #
2 3 4 5
Me
an
# o
f s
pe
cie
s/
ce
ns
us
po
int
0.0
0.5
1.0
1.5
2.0
2.5
3.0
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Northern Flying Squirrel and Forest Management
• Home Range• Habitat Associations• Den Trees
© Sean Bogle
Authors: Jaya Smith, *Douglas Kelt, *Dirk Van Vuren, *Michael Johnson
* Co-Principle Investigators on the Plumas Lassen Administrative Study Small Mammal Module
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Flying Squirrel Methods
Trapping
Collaring
… and Radiotracking
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Home Range
• Helps forest managers make decisions:– How much area is needed?– What habitat types are in
the home range?
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Home Range Area (Fixed Kernel)
• ResultsMean area = 27.2 Acres
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Flying SquirrelsSpatial Organization
•Allows for inference upon social interaction
•Provides further information regarding spatial requirements
Mea
n %
Ove
rlap
0
20
40
60
80
female/female female/male male/malemale ---------female ---------
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Flying SquirrelsHabitat Analysis
• Wildlife Habitat Relations (WHR) layer with 7 categories:– Riparian– Sierra mixed conifer (small,
medium and large)– Monocultures– Wet meadows – Barren areas– Chaparral– Bodies of water
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Flying SquirrelHabitat Preferences
• Compare Used habitat with Available habitat
• Assessed on two scales:– Broad scale- Across the
forest– Narrow scale- Within the
home range itself
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• Broad scale-Large Sierra mixed conifer-Medium Sierra mixed conifer
Results-
• Narrow scale-Large Sierra mixed conifer-Medium Sierra mixed conifer
Flying SquirrelHabitat Preferences
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Den Trees
• Methods– Telemetry/Homing– Use vs. Availability
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AvailableTrees
DenTree
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Den Trees Used
White FirBlack Oak
DouglasFir Red
FirIncense Cedar
Bigleaf Maple
Jeffrey Pine
Lodgepole PinePonderosa Pine
92 FlyingSquirrel Dens
Measured
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Sapling
Poletimber
Small sawtimber
Large sawtimber
Small hardwood
Large hardwood
Perc
ent
0
10
20
30
40
50
60
70
AvailableUsed
White Fir Douglas Fir Black Oak Red Fir0.0
0.1
0.2
0.3
0.4
AvailableUsed
Den Tree Species
Den Tree Size
Den Trees:Used vs. Available
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Dusky-footed woodrat Results
• Innes et al. 2007 & Innes et al. 2008
• Abundance:↑ oak density = ↑ woodrat density
• Tree house sites:large oaks, large snags
• Ground house sites:↑ large logs, ↑ large stumps, and ↑ slope
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Woodrats and Flying Squirrels:Common Ground?
• Mature black oak very important
• Large conifers preferred by NFS provide large logs and large stumps preferred by DFW
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Wildfire Restoration & Prevention• Habitat associations
– California spotted owl prey: flying squirrels, woodrats, deer mice
– Forest-wide small mammal assemblages• Spatial requirements
– California spotted owl prey: flying squirrels and woodrats
• Trends in abundance– California spotted owl prey:
flying squirrels, woodrats, deer mice– Forest-wide small mammal assemblages
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Work Plan- FY 2010
• One final season of long-term grid sampling will provide us with a balanced 4-year pre-treatment and 4-year post-treatment sample.
• Analyze long-term grid data and prepare manuscript on small mammal response to fuels management.
• Analyze landscape transect data and prepare manuscript of small mammal habitat associations and distribution in Plumas National Forest.
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Thank You! Questions?
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Den Trees Used vs. Available
Hardwoods
Tree Size (cm)5 10 15 20 25 30 35 40 45 50 55 60
Pro
porti
on U
sed
0.0
0.1
0.2
0.3
0.4
Availability Use
4 6 8 10 12 14 16 18 20 22
SmallLarge
Conifers
Use Versus Availability of Conifers
Tree Size (cm)10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
0.0
0.1
0.2
0.4
0.5
AvailableUse
4 8 12 16 20 24 28 32 3640 44 4852 56 60(inches) (inches)
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Den Trees; Use vs Availability
• Den Tree Ranking (most to least important):1. Large hardwood (≥13 inch dbh)2. Large sawtimber (Conifer ≥21 inch dbh) 3. Small hardwood (4-13 inch dbh)
4. Small sawtimber (Conifer 11-21inch dbh)5. Poletimber (Conifer 3-11 inch dbh)
6. Sapling (Conifer and hardwood <3 inch dbh)
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R2 = 0.68P=0.08
0
1
2
3
0 5 10 15 20 25
Large oak density ( >30 cm dbh)(ha-1)
Woo
drat
den
sity
(ha-1
)
(Innes et al. 2008)
(Innes et al. 2007)
Dusky-footed woodrat Results
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Telemetry/Home Range Analysis
Modified from James Wilson
Home RangeEstimates
ConcurrentTriangulation
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Overlay Habitat Map with Home Range and Points
+ =
Courtesy of Jaya Smith