Small Mammal Module
Objective: 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 measurements
Northern flying squirrels (completed)
Dusky-footed woodrats (completed)
Long-Term Grids
• 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
Overall Yearly Trends
deer mice
chipmunks
flying squirrels
woodrats
Mean Abundance
20
15
10
5
0
2003
2004
2005
2006
Year
2007
2008
2009
Long-Term Grids
Habitat Types
Douglas Fir
Pine - Cedar
Red Fir
White Fir
Flying Squirrels
Woodrats
8
2.5
7
2.0
Mean Abundance
6
5
1.5
4
1.0
3
2
0.5
1
0
0.0
2005
2006
2007
2008
2009
2003
2004
2005
2006
2007
2008
2009
Long-Term Grids
Habitat Types
Douglas Fir
Pine - Cedar
Red Fir
White Fir
Chipmunks
Deer Mice
50
60
40
50
Mean Abundance
Douglas Fir
Pine - Cedar
Red Fir
White Fir
40
30
30
20
20
10
10
0
0
2003
2004
2005
2006
2007
2008
2009
2003
2004
2005
2006
2007
2008
2009
Long-Term Grids
Treatments
Control
Group-select
Heavy-thin
Light-thin
Flying Squirrels
Woodrats
1.4
1.2
Mean Abundance
2.0
Treatment
1.0
1.5
Treatment
0.8
0.6
1.0
0.4
0.5
0.2
0.0
0.0
2005
2006
2007
2008
2009
2003
2004
2005
2006
2007
2008
2009
Long-Term Grids
Treatments
Control
Group-select
Heavy-thin
Light-thin
Chipmunks
Deer Mice
Mean Abundance
20
20
Treatment
Treatment
15
15
10
10
5
5
0
0
2003
2004
2005
2006
2007
2008
2009
2003
2004
2005
2006
2007
2008
2009
Long-Term Grids
100
Mean Cone Abundance
Annual Snow Fall
Mean Mouse Abundance
80
Mice over Time
60
40
?
20
0
2003
2004
2005
2006
2007
2008
2009
2010
Year
• 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.
Long-Term Grids
More on Mice
observed mouse abundance
predicted mouse abundance
Mean Abundance
80
60
40
20
Y= (-0.41 * snow) + (0.32 * fir) + (0.20 * pine) + 40.24
0
2004
2005
2006
2007
Year
2008
2009
Landscape
Transects
Methods
1
2
3
4
5
50 m
35 m
TU-3
Landscape Transects
Results
• 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.
Abundance:
6.58 (+ 0.24) animals/census pt.
Mean # of individuals/census point
10
8
6
4
2
0
2
3
4
Treatment Unit #
5
Species richness:
2.02 (+ 0.05) species/census pt
Mean # of species/ census point
3.0
2.5
2.0
1.5
1.0
0.5
0.0
2
3
4
Treatment Unit #
5
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
Flying Squirrel Methods
… and Radiotracking
Trapping
Collaring
Home Range
• Helps forest managers
make decisions:
– How much area is needed?
– What habitat types are in
the home range?
Home Range Area (Fixed Kernel)
• Results
Mean area = 27.2 Acres
Flying Squirrels
Spatial Organization
•Allows for inference upon social interaction
•Provides further information regarding spatial requirements
Mean % Overlap
80
60
40
20
0
female/female
female/male
male/male
male --------female ---------
Flying Squirrels
Habitat 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
Flying Squirrel
Habitat Preferences
• Compare Used habitat
with Available habitat
• Assessed on two scales:
– Broad scale- Across the
forest
– Narrow scale- Within the
home range itself
Flying Squirrel
Habitat Preferences
Results• Broad scale
-Large Sierra mixed conifer
-Medium Sierra mixed conifer
• Narrow scale
-Large Sierra mixed conifer
-Medium Sierra mixed conifer
Den Trees
• Methods
– Telemetry/Homing
– Use vs. Availability
Den
Tree
Available
Trees
Den Trees Used
92 Flying
Squirrel Dens
Measured
Black Oak
White Fir
Ponderosa Pine
Lodgepole Pine
Douglas
Red
Fir
Fir
Jeffrey Pine
Bigleaf Maple
Incense Cedar
0.4
Den Trees:
Used vs. Available
Available
Used
0.3
0.2
0.1
Den Tree Species
0.0
White Fir
Douglas Fir
Black Oak
Red Fir
70
60
Available
Used
Percent
50
40
30
20
Den Tree Size
10
0
g
plin
Sa
er
er
er
ood
ood
mb
mb
mb
rdw
rdw
wti
wti
leti
a
a
a
a
o
h
h
s
s
P
all
ge
all
ge
Sm
Lar
Sm
Lar
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
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
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
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 posttreatment 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.
Thank You!
Questions?
Den Trees Used vs. Available
Hardwoods
Conifers
Use Versus Availability of Conifers
Proportion Used
0.4
0.5
Availability
Use
Available
Use
0.4
0.3
Small
0.2
Large
0.2
0.1
0.1
0.0
0.0
5
10
4
15
6
20
25
30
35
40
45
50
55
20
8 10
12
14
16
18
22
Tree Size (cm)
(inches)
60
10
30 40 50 60 70 80 90 100 110 120 130 140 150
4 208 12
16 20 24 28 32 3640 44 4852 56 60
Tree Size (inches)
(cm)
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)
Dusky-footed woodrat Results
(Innes et al. 2007)
-1
Woodrat density (ha )
3
2
1
R2 = 0.68
P=0.08
0
0
(Innes et al. 2008)
5
10
15
20
-1
Large oak density ( >30 cm dbh)(ha )
25
Telemetry/Home Range Analysis
Concurrent
Triangulation
Home Range
Estimates
Modified from James Wilson
Overlay Habitat Map with Home
Range and Points
+
=
Courtesy of Jaya Smith