kristy campbell winter ecology,spring 2014 mountain research station, university of colorado,...

KRISTY CAMPBELL

WINTER ECOLOGY,SPRING 2014Mounta in Research Stat ion ,

Univers i ty o f Co lorado , Boulder

The Effect of Elevation on Mammal Behavior and Abundance in Winter

Introduction

Morphological and physiological adaptations allow mammals to survive the winter in Colorado.

Behavioral Adaptation – Some mammals utilize the insulative properties of snow.

Physical Adaptation – The Snowshoe Hare has large feet that allow it to easily walk across the snow (like snowhoes)

Introduction

Because of the deeper snowpack at higher elevations, larger mammals such as moose and deer are found more often at lower elevations (Poole & Stuart-Smith 2006).

Introduction

Studies have shown that species diversity and abundance of small mammals in riparian zones is greater than in upland areas (Doyle 1990).

These mammals may be drawn to the riparian zones for water, abundance of vegetation, or abundance of other prey mammals.

• For these reasons, I focused my study on riparian zones at different elevations.

Introduction

Hypothesis – The proportion of smaller to larger mammals increases with elevation in the winter.

Prediction - Tracks from smaller mammals (such as squirrels and Snowshoe Hares) will be more abundant at higher elevations than at lower elevations. Tracks from larger mammals (such as ungulates), will be more abundant at lower elevations.

Methods

2 elevations along Como Creek50 m transect through the riparian areaObserved animal tracks at 10 random points

along the transect

10 mRiparian zone

Methods

3020 m

2857 m

Methods

Measured Snow depth and type of vegetation at both sites. Analyzed differences in species frequency and density at both

elevations using a Chi-Square Test.

Site 1 - 3020 m site 2 - 2857 m

Site 1 Site 2

Snow Depth – 90 cm

Vegetation: Willows Lodegpole Pine Spruce Aspen

Slope – flat area ( 4◦)

Snow Depth – 60 cm

Vegetation: Willows Lodgepole Pine Spruce Aspen

Slope – flat area ( 6◦)

Results

Results: Density of Tracks

Density of track found at site 1 (high elevation) and site 2 (low elevation)Site 1 Site 2

Chi-Square Test of Independence

H0 = The density at each site is not different from a random distribution. P = 0.56There was no significant difference from random. The null hypothesis could not be rejected.

Results: Relative Frequency of Tracks

Chi- Square Goodness of Fit Test

Ho – The frequency distributions are the same.P = 0.90There was no significant difference in relative frequency of tracks found between site 1 and site 2. The null hypothesis could not be rejected.

Relative Frequency of tracks found at site 1 (high elevation) and site 2 (low elevation)

Results: Absolute Frequency of Tracks

Chi- Square Goodness of Fit Test

Ho – The frequency distributions are the same.P = 0.95There was no significant difference in absolute frequency of tracks found between site 1 and site 2. The null hypothesis could not be rejected.

Absolute Frequency of tracks found at site 1 (high elevation) and site 2 (low elevation)

Discussion

The frequency and density of different mammal tracks found at both sites tested were statistically identical to each other.Vegetation at both sites was the same.Elevation was not as different as planned.Snow depth was different, but the top layer of

snow was firm. The coyote tracks found at the high elevation did not penetrate deep into the snow.

Discussion

My hypothesis was not supported. However, due to the constraints of my study, I think that further research could be done:More replicates need to be done at each site.There needs to be a larger difference in

elevation.At least one more lower elevation needs to be

studied. Perhaps asking permission of private land owners to study animal tracks near the creek.

3200 m

2857 m

2469 m

Discussion

Not all methods could be carried out as planned:I planned to begin collecting data at 3200 m

(the top of Komo Creek), but I could not find the creek. I began instead at 3020 m.

I planned to collect my final set of data at an elevation of 2469 m, but I could not access the sampling area because it was on private land.

References

Doyle, A. T. 1990. Use of Riparian and Upland Habitats by Small Mammals. Journal of Mammalogy. Vol 71. No. 1: 14-23.

Gillis, E. A., Hilk, D.S., Boonstra R., Karels, T.J., and Krebs, C.J. 2005. Being High is Better: Effects of Elevation and Habitat on Arctic Ground Squirrel Demography. OIKOS 108:231-240.

Poole, K.G., and Stuart-Smith. 2006. Winter Habitat Selection by Female Moose in Western Interior Montane Forests. Canadian Journal of Zoology. Vol 84: 1823- 1832.