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