Squirrel Along the Sourdough Trail in Winter S tudy conducted by Bryan Horsley CU Boulder EBIO Program Winter Ecology 2016 Research Question Is there a negative trail effect on the abundance of snowshoe hares andor red squirrels along the Sourdough trail in winter ID: 682516
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Slide1
Trail Effects on the Abundance of Snowshoe Hare and Red
Squirrel Along the Sourdough Trail in Winter
S
tudy conducted by Bryan Horsley
CU Boulder EBIO Program
Winter Ecology 2016Slide2
Research Question
Is there a negative “trail effect” on the abundance of snowshoe hares and/or red squirrels along the Sourdough trail in winter?I hypothesize that there is an effect and my research is designed to test this.Slide3
Snowshoe Hare (Lepus americanus
)Range: Canada, Alaska, Rocky Mtns, Appalachian MtnsRemains active through winterMostly nocturnal or crepuscularLeaps up to 12ft when moving quickly
Coat color plasticity
Food switching
Opportunistic: carrion!
Large heavily-furred rear feetShort ears and tailCanada Lynx: predatorSource: Reid 2006Slide4
Red Squirrel (
Tamiasciurus hudsonicus)Range: Canada, Alaska, Northeast U.S., Rocky and Appalachian Mtns.Remains active through winter
Conspicuous forest resident
Eats pine seeds primarily
Also nuts, fungi, fruit, sap, birds, eggs
White eye ringEars tufted in winterMakes insulated nestPrefers tree cavities
Source: Reid
2006Slide5
Background
“Quiet, non-consumptive” recreation have negative impacts on wildlife Non-motorized, non-hunting activititesSeemingly low-impact activities
A
challenging
ethical issue (personal)
Source: Reed &
Merenlender
2008Slide6
N
egative effects of recreational trailsSpook and flee - wildlife driven away from trail.Less bird nesting near trails (Miller, et al. 1998).
Dogs increase wildlife response
(Banks & Bryant 2007).
Frequent short-term disturbances can result in long term changesSlide7
A Potential Cascade Effect on Snowshoe Hare
Snowshoe hare is regularly flushed from feeding near trailWasted energy running Didn’t eat enough
Malnutrition
Death
Moves away from trail area permanently Change in habitat structureSnowshoe hare no-longer in areaImpacts on predators (Lynx canadensis
)
No food Leave or die
Hares no-longer eating Changes in vegetation structure (more growth)
Hare predators gone
Predator release effects on other animals Imbalance in numbers
Predator range reduced Lowered predator population
Changes in vegetation structure
Change in habitat stability for other inhabitants
Supporting further predator release benefits Greater imbalance
Based on a flow diagram in
Wildlife and Recreationists: Coexistence Through Management and
Research
(Knight and
Gutzwiller
, 1995).Slide8
MethodsSurvey 4 transects (2 meter W x 0.5 km L) for tracks in the snow
2 transects on the Sourdough trail2 transects 0.2 km off-trail, parallel to the on-trail transectsCompare on-trail vs. off-trail track abundance of each species (SS, SQ)
Low impact
ski technique demonstrated
by my trusty
research assistant
Dave M.Slide9
Track IdentificationSlide10
Null Hypothesis:
Proximity to the Sourdough trail has no effect on the abundance of snowshoe hares and/or red squirrels.Alternate Hypothesis:
Proximity to the Sourdough trail
does have an effect
on the abundance of snowshoe hares
and/or red squirrels.Slide11
ResultsSlide12
Analysis
Reject null hypothesis for snowshoe hareThere is a negative trail effect on snowshoe hare based on my researchAccept null hypothesis for red squirrelThere is not a negative trail effect on red squirrel based on my researchSlide13
Conclusion
Results suggest a need for more ecology-based managementTrail placement / re-routing?Usage typesRegulations
Seasonal usage (trails closed for mating)
Additional research
Which species are most impacted?
How can pressure be alleviated?Slide14
Questions?Slide15
Sources
Banks, P. B., & Bryant, J. V. (2007). Four-legged friend or foe? Dog walking displaces native birds from natural areas. Biology letters, 3
(6), 611-613
.
Ellsworth, E., & Reynolds, T. D. (2006). Snowshoe hare (Lepus
americanus): a technical conservation assessment. USDA Forest Service, Rocky Mountain Region.Knight, Richard L. and Kevin Gutzwiller. 1995. Wildlife and Recreationists: Coexistence Through Management and Research. Island Press, Washington D.C. Miller, S. G., Knight, R. L., & Miller, C. K. (1998). Influence of recreational trails on breeding bird communities. Ecological Applications,
8
(1), 162-169.Reed, S.E. and A.M.
Merenlender
. 2008. Quiet,
nonconsumptive
recreation reduces protected area effectiveness.
Conservation Letters
, 1(3), 146-154.
Reid, Fiona A. 2006. Mammals of North America.
Peterson Field Guides
. Houghton Mifflin Company, New York.