Small Mammal Module · -Focal species: radiotelemetry & habitat measurements. Northern flying...
Transcript of Small Mammal Module · -Focal species: radiotelemetry & habitat measurements. Northern flying...
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)
• 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
Year
2003 2004 2005 2006 2007 2008 2009
Mea
n Ab
unda
nce
0
5
10
15
20deer micechipmunksflying squirrelswoodrats
Long-Term Grids
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
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
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
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
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.
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
2 34
5
1TU-3
Landscape TransectsMethods
50 m
35 m
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.
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
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
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
Trapping
Collaring
… and Radiotracking
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)
• ResultsMean area = 27.2 Acres
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 ---------
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
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
• Broad scale-Large Sierra mixed conifer-Medium Sierra mixed conifer
Results-
• Narrow scale-Large Sierra mixed conifer-Medium Sierra mixed conifer
Flying SquirrelHabitat Preferences
Den Trees
• Methods– Telemetry/Homing– Use vs. Availability
AvailableTrees
DenTree
Den Trees Used
White FirBlack Oak
DouglasFir Red
FirIncense Cedar
Bigleaf Maple
Jeffrey Pine
Lodgepole PinePonderosa Pine
92 FlyingSquirrel Dens
Measured
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
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 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.
Thank You! Questions?
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)
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)
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
Telemetry/Home Range Analysis
Modified from James Wilson
Home RangeEstimates
ConcurrentTriangulation
Overlay Habitat Map with Home Range and Points
+ =
Courtesy of Jaya Smith