FORAGE SELECTION BY THE AMERICAN PIKA (OCHOTONA
PRINCEPS): COMPARING VEGETATION COMMUNITIES, PIKA

HARVESTING AND PLANT NUTRITION IN CONTRASTING
HABITATS
BY

MARISA LEUNG
A THESIS SUBMITTED IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
BACHELOR OF NATURAL RESOURCE SCIENCE (HONS.)
IN THE DEPARTMENT OF
NATURAL RESOURCE SCIENCES
AT
THOMPSON RIVERS UNIVERSITY

THESIS EXAMINING COMMITTEE

Karl W. Larsen (Ph.D.) (Supervisor), Professor, Dept. Natural Resource Sciences

Wendy Gardner (Ph.D.), Associate Professor, Dept. Natural Resource Sciences

John Karakatsoulis (Ph.D.), Senior Lecturer, Dept. Natural Resource Sciences
Dated the 11th day of April 2014, in Kamloops, British Columbia, Canada

ABSTRACT
Thesis supervisor: Karl W. Larsen
Understanding the relationship between animal populations and the vegetative
heterogeneity of their native habitat is becoming increasingly important as natural resource
extraction, such as mining, becomes a dominant influence on landscapes in the southerninterior of British Columbia. Identifying how wildlife (particularly herbivores) are able to
use anthropogenic plant species will allow us to better manage the quality and quantity of
forage in these anthropogenic ecosystems. Reclamation initiatives at Highland Valley
Copper Mine focus on converting waste-rock and dump site locations into land that supports
plant communities composed of agronomic and native species. The presence of American
Pikas (Ochotona princeps) in this and surrounding landscapes creates an opportunity to
investigate the plants harvested by these animals compared to that available, and also how
this pattern varies between natural and anthropogenic habitats. In August 2013, I surveyed
the plant communities surrounding a variety of pre-established pika den sites, finding that
native and anthropogenic locations showed little similarity in terms of plant species diversity,
particularly in terms of the most abundant species within each location. An examination of
pika haypiles (harvest piles) in October 2013 showed that although common plants were
being harvested, the animals also used plants that were less common. Plant species identified
as most abundant within the haypiles were primarily shrubs, forbs and grasses. I also
determined that the plants harvested by the pikas were not necessarily the most abundant nor
the most nutritional. Overall, this study revealed the foraging and dietary plasticity of pikas
in this region, and in tandem with a larger, overarching project, provides an improved
understanding of the pika population inhabiting this atypical environment.

ii

TABLE OF CONTENTS
ABSTRACT .............................................................................................................................. ii
LIST OF FIGURES ................................................................................................................. iv
LIST OF TABLES ................................................................................................................... vi
ACKNOWLEDGEMENTS .................................................................................................... vii
DEDICATION ........................................................................................................................ vii
INTRODUCTION .................................................................................................................... 1
Wildlife Habitat and Habitat Suitability ............................................................................... 1
Reclamation and Mining ....................................................................................................... 2
Vegetation, Reclamation and Herbivores ............................................................................. 3
Pikas as Small Herbivores .................................................................................................... 3
My Study and Main Objectives ............................................................................................ 7
MATERIALS AND METHODS .............................................................................................. 9
Study Area ............................................................................................................................ 9
Field Methods ..................................................................................................................... 10
Sample Preparation for Nutrient Analysis .......................................................................... 14
Laboratory Methods ............................................................................................................ 14
Statistical Analysis .............................................................................................................. 15
Aspen Leaf Analysis ........................................................................................................... 16
RESULTS ............................................................................................................................... 16
Plant Community Comparisons .......................................................................................... 16
Haypile Comparisons .......................................................................................................... 17
Nutritional Analysis ............................................................................................................ 22
DISCUSSION ......................................................................................................................... 28
Plant Community and Species Diversity ............................................................................ 29
Plant Community and Haypiles .......................................................................................... 30
Haypiles and Nutrition ........................................................................................................ 31
CONCLUSION ....................................................................................................................... 34
LITERATURE CITED ........................................................................................................... 35
APPENDIX A ......................................................................................................................... 39
APPENDIX B ......................................................................................................................... 39

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LIST OF FIGURES
Figure 1 – Adult American Pika (Ochotona princeps) (a) with a tracking collar and ear
identification tag harvesting kinnikinnick (Arctostaphylos uva-ursi) in an anthropogenic
habitat; Juvenile American Pika (Ochotona princeps) (b) (not collared nor ear tagged) in
a native habitat adjacent to Highland Valley Copper Mine, British Columbia, Canada.
Photograph by Author (August 2013) ................................................................................. 4
Figure 2 – Examples of haypiles created by American Pikas (Ochotona princeps) at
Highland Valley Copper Mine, British Columbia, Canada. (a-b) Typical haypiles found
at native denning sites, (c) Typical haypile found at anthropogenic denning sites. All
photographs by Author (August 2013)................................................................................ 6
Figure 3 – Various examples of anthropogenic sites inhabited by the American Pika
(Ochotona princeps) at Highland Valley Copper Mine, British Columbia, Canada; (a)
roadside in Bethlehem, (b) backside of Bose Road dam, (c) waste-rock dump site in
Bethlehem, (d) waste-rock and side cast dump site adjacent to a newly logged cut block
in Highmont, (e) side cast from a road in Highmont, (f) waste-rock dump site in
Highmont. All photographs by Author (August 2013) ..................................................... 11
Figure 4 – 15 study sites at Highland Valley Copper Mine, British Columbia, Canada. Plots
consisted of 5 and 20 m radiuses each. Full location names are in Appendix A. Map
courtesy of Kirby Papineau - GIS Tech, Forsite Consultants Ltd., Kamloops, British
Columbia, Canada ............................................................................................................ 12
Figure 5 – Various examples of natural talus on native sites inhabited by the American Pika
O.princeps adjacent to Highland Valley Copper Mine, British Columbia, Canada. All
photographs by Author (August 2013).............................................................................. 13
Figure 6 – Average percent cover plant species abundance across denning sites of the
American Pika (Ochotona princeps) in native habitat (top) and anthropogenic habitat
(bottom) at Highland Valley Copper Mine, British Columbia, Canada. The species list on
the abscissa consists of the entire assemblage of species identified on both the
anthropogenic and native sites. Lack of a bar indicates that the species was not found.
(Error bars indicate +/- 1 standard deviation). An exhaustive list of the common and
scientific names of all plant species is presented in Appendix B. .................................... 18

iv

Figure 7 - Number of plant species identified in each plant community surrounding the den
sites of the American Pika (Ochotona princeps), recorded during the summer season
(August 1st-5th, 2013), at Highland Valley Copper Mine, British Columbia, Canada.
Native sites are illustrated as gray bars and anthropogenic sites are depicted as patterned
bars. The abbreviations on the abscissa are names associated with each site. Site
locations can be identified on the orthographic map (Figure 5) and full site names are
listed in Appendix B. ........................................................................................................ 19
Figure 8 - Number of identified plant species within each haypile of the native (solid) and
anthropogenic (patterned) den sites of the American Pika (Ochotona princeps) recorded
during the fall season (October 10th, 2013) at Highland Valley Copper Mine, British
Columbia, Canada ............................................................................................................. 21
Figure 9 - Most abundant species identified in the haypiles of native den sites of the
American Pika (Ochotona princeps). Figure 9 (a) shows the number of den sites where
the plant species were detected, whereas 9 (b) depicts the average percent volume that
each species appeared in the haypiles. Data collected on October 10th, 2013 at Highland
Valley Copper Mine, British Columbia, Canada. ............................................................. 23
Figure 10 - Most abundant species identified in the haypiles of anthropogenic den sites of
the American Pika (Ochotona princeps). Figure 10 (a) shows the number of den sites
where the plant species were detected, whereas Figure 10 (b) depicts the average percent
volume that each species appeared in the haypiles of the pikas. Data collected on
October 10th, 2013 at Highland Valley Copper Mine, British Columbia, Canada. .......... 24
Figure 11 – Nitrogen analysis outputs for 46 species collected during the summer season
(August 1st-5th, 2013) from native 20m plot locations at Highland Valley Copper Mine,
Logan Lake, British Columbia, Canada. Most abundant species identified as comprising
portions of native haypiles of the American Pika (Ochotona princeps) are indicated by
dark gray bars. The species list on the abscissa is listed alphabetically in order of
functional groups as depicted in Appendix B. .................................................................. 26
Figure 12 - Nitrogen analysis outputs for 39 species collected during the summer season
(August 1st-5th, 2013) from 7 anthropogenic 20m plot locations at Highland Valley
Copper Mine, Logan Lake, British Columbia, Canada. Most abundant species identified
as comprising portions of native haypiles of the American Pika (Ochotona princeps) are
indicated by dark gray bars. The species list on the abscissa is listed alphabetically in
order of functional groups as depicted in Appendix B. .................................................... 27

v

LIST OF TABLES
Table 1 – Use of the Jaccard index to determine the similarity between the plant
communities surrounding the den sites of American Pikas (Ochotona princeps) between
native and anthropogenic habitats, as recorded during the summer season (August 1st to
5th, 2013), at Highland Valley Copper Mine, British Columbia, Canada. 1 = present, 0 =
not present. Scientific names for plants are provided in Appendix B. ............................ 20
Table 2 – Comparison of the relatively abundant plant species in the vegetation communities
surrounding pika denning sites with those in the animals’ haypiles. Binary values
represent presence (1) and absence (0) of the plant species. Jaccard’s index (J-values)
indicate relatively little similarity between the two groups of plants. For scientific names
of the plant species see Appendix B. ................................................................................ 25
Table 3 – Codes identifying locations of American Pika (Ochotona princeps) in the
Highland Valley Copper Mine operating area (anthropogenic habitat) and adjacent native
habitat, including detailed site information, 2013 ............................................................ 39
Table 4 – Vegetation observed near sites occupied by American Pika (Ochotona princeps) in
the Highland Valley Copper Mine operating area (anthropogenic habitat) and adjacent
native habitat, 2013 ........................................................................................................... 40

vi

ACKNOWLEDGEMENTS
Thank you to my supervising professor, Karl Larsen, for continuous support throughout the
duration of my project; to my committee members, Wendy Gardner and John Karakatsoulis,
for much appreciated field assistance and methodology guidance; to Cheryl Blair for getting
me involved with her Master’s study and helping both in the field and during the writing
process; to Lauchlan Fraser for the use of his research lab and statistical guidance; to Heather
Richardson and Dan Denesiuk for helping conduct my nutritional analysis; to Highland
Valley Copper Mine for allowing me to collect data within their operating area; to Amber
Merko and Eric Spilker for all the field work help during my August data collection period;
to all my friends that helped edit my thesis and poster; and lastly, most of all to my family for
encouraging me, motivating me and giving me strength throughout this process.

DEDICATION
To my Grandmothers – For you are the strength that gets me through the rough times and the
passion that guides me through life’s endeavours.

vii

INTRODUCTION
Wildlife Habitat and Habitat Suitability
Understanding wildlife-habitat relationships is perhaps the dominant issue in animal
ecology. Historically, studies have focused on the so-called ‘natural’ foraging patterns of
animals (Connor 1983, Huntly et al. 1986, Dearing 1996, Dearing 1997), but as landscapes
become increasingly anthropogenic in origin, the need to understand how animals respond to
habitat changes becomes progressively more important (Apps et al. 2004, Swank 2004,
Hunter 2007, Howie 2008, Manning and Hagar 2011). Intuitively, animal populations only
will persist in a given area if fundamental resource requirements are present, and adaptations
enabling individual animals to cope with environmental changes and inter/intraspecific
competition remain viable (Morrison et al. 2006). Identifying how wildlife is able to use
anthropogenic habitat allows us to identify situations where long-term persistence by animals
may be difficult or unlikely, and where management intervention is required.
One recurrent issue regarding wildlife-habitat relationships is whether or not the
presence or absence of a species is an indicator of habitat suitability (Bender et al. 1998,
Morrison et al. 2006, DeGabriel et al. 2008, Manning and Hagar 2011). One argument is that
animals settle in the most attractive available habitat patch, regardless of whether it is the
“best” in terms of providing critical resources (Battin 2004). Habitat therefore does not
necessarily have to be optimal in order for individual animals to be present, and although
individual fitness may be compromised, the presence of a species may not necessarily be an
indicator of habitat suitability. However, the plasticity and/or adaptability of animals may
allow increasing individuals to survive in atypical environments that are influenced by
human activity. Indeed, many species, plants and animals alike, have adapted to the new
stresses created by anthropogenic influences, even in close proximity to humans (Hunter
2007). With the demand for natural resources unlikely to relent, the ability of species to cope
with changing habitats will be increasingly important, and studies that reveal the implications
(or lack thereof) of animals using anthropogenic habitat will in turn be critical to our
stewardship of the environment.

Reclamation and Mining
Natural resource extraction, such as mining and forestry, has become a dominant
influence on landscapes in the southern-interior of British Columbia. Reclamation
considerations require the knowledge of native habitat and population ecology in order to
mitigate the impacts to the environment caused by these resource extraction operations. Not
only does resource extraction eradicate habitat for native plant and animal species, but also
fragments the landscape, changing the functionality of the ecosystem. At the same time, this
disturbance has the capability to provide new habitat for various species through reclamation
strategies, and thus the reclamation of vegetation communities has become an increasingly
important tool in negating or mitigating the impact of resource extraction.
The re-establishment of vegetation communities is central to the reclamation of
landscapes altered by mining. In particular, mining that involves the surface removal and
disturbance of vegetation, soil and other ecosystem attributes can only be mitigated by a
clear understanding of how (or if) the re-establishment of new vegetation communities will
replicate that of the original system, or provide an equivalent capacity to the original plant
community. The Health, Safety and Reclamation Code for British Columbia states, “it is the
duty of every owner, agent and manager to institute and carry out a program of
environmental protection and reclamation in accordance with the documented standards
throughout the life of the mine” (section 10.7.1 – Reclamation and Closure – Reclamation
Standards: Ministry of Energy, Mines and Petroleum Resources 2008). The ultimate
objective of vegetative reclamation is to return disturbed land to a capacity that is equivalent
to or greater than the pre-disturbance state of the area. Reclamation strategies put forth by
mining operations include creating suitable planting mediums via soil or biosolids,
developing self-sustaining vegetation cover by planting a combination of agronomic and
native grass, forb and tree species, promoting the re-establishment of native plant and tree
species and creating and/or maintaining biodiversity in as many environments as possible
(Jones et al. 1996, Freberg and Gizikoff 1999). Ultimately, these efforts should provide
suitable habitat for a number of wildlife species, ideally by returning pre-existing plants and
animal communities to the landscape.

2

Vegetation, Reclamation and Herbivores
The response of wildlife to re-established vegetation (through reclamation or other
pathways) should be relatively easy to demonstrate for herbivores. Herbivore species that
become established in a reclamated vegetation community will be determined to a large part
by whether original forage species are returned to the site, or whether the animals are able to
use new, alternative species that have been established. Herbivores may respond directly to
changes in vegetation communities, including those that are anthropogenic in origin. To
maximize the quality of their diet, herbivores may forage on a variety of plants that differ in
regards to palatability, digestibility, and nutrient content (Cameron et al. 2009). Thus,
understanding the relationship between herbivore populations and the vegetative
heterogeneity of their native habitat is becoming increasingly important due to its prominent
relationship to reclamation initiatives. Disturbances have the ability to alter the foraging
decisions of species (Hovland et al. 1999, Howie 2008, Manning and Hagar 2011) through
the planting of agronomic species during reclamation efforts. For example, human
alterations to the environment and plant communities have the potential to compromise the
quality of the food available to herbivores (Dearing 1996). Additionally, anthropogenicallymodified or altered habitat may affect foraging and energetic considerations, nutritional
availability, and the dispersion of food plants (Cameron et al. 2009).

Pikas as Small Herbivores
The American Pika (Ochotona princeps, O. Lagomorpha, F. Ochotonidae) is a small,
herbivorous mammal known for its unusual plant caching behaviour (Figure 1). The animal
has a widespread distribution throughout the western United States of America and
southwestern Canada, where they are found in Alberta and British Columbia (Beever and
Smith 2011). In British Columbia, they can be found throughout the southern part of the
Rocky Mountains, the southern-interior region and along the southern portion of the west
coast. The American Pika, along with other Nearctic pika species, is suggested to be a
biogeographic indicator of cool, mesic, rocky areas (Morrison et al. 2006).

3

a

b

Figure 1 – Adult American Pika (Ochotona princeps) (a) with a tracking collar and ear
identification tag harvesting kinnikinnick (Arctostaphylos uva-ursi) in an anthropogenic
habitat; Juvenile American Pika (Ochotona princeps) (b) (not collared nor ear tagged) in a
native habitat adjacent to Highland Valley Copper Mine, British Columbia, Canada.
Photograph by Author (August 2013)

4

Pikas are known as high-elevation species, sensitive to warm temperatures and possessing a
limited ability to disperse between habitat patches (Varner and Dearing 2014). They are
among the few small mammal species in Canada that are known to not hibernate over-winter,
and they also demonstrate coprophagy – re-ingesting their initial fecal matter to obtain
optimal nutrient extraction. During the late summer months they harvest plants not only for
immediate consumption but also for over-winter storage (Dearing 1996, Dearing 1997,
Gliwicz et al. 2006).
Pikas inhabit regions where most of the ground-cover vegetation is annual (limited or
absent during winter) and this requires them to spend 25-55% of their seasonal above-surface
activity period hoarding plant material to prepare for the winter months (Dearing 1997).
Above ground plant material, usually green parts of the plant or yellow deciduous leaves, is
collected by the pikas. The plant material is then carried in the mouth (either as a single
clipping or a bundle of clippings) back to the denning site (within the animal’s territory),
where it is placed in ‘haypiles’. The clippings are laid out on exposed rock faces for drying
prior to subsurface caching within the talus or rocky patches of the den site (Figure 2).
One of the most controversial debates regarding the foraging behaviour of the
American Pika is whether or not they are selective or opportunistic in their winter caching
strategies (Gliwicz et al. 2006). The contents of pika haypiles have been subjected to
numerous studies that provide arguments for both selective versus opportunistic plant haying
by pikas. Gliwicz et al. (2006) compared studies on pika haypiles and concluded that older
papers (1935-1972) carried the prevailing opinion that pikas demonstrate a generalist type of
foraging behaviour, utilizing whatever plants were available; conversely, more recent papers
(1972-2001) indicate a selective foraging behaviour based on observations and nutritional
analyses (Varner and Dearing 2014). Clearly understanding the foraging behaviour of the
American Pika is central to understanding the ecology of the animal (Dearing 1996),
particularly temporal and spatial responses to different environments.

5

a

b

c

Figure 2 – Examples of haypiles created by American Pikas (Ochotona princeps) at
Highland Valley Copper Mine, British Columbia, Canada. (a-b) Typical haypiles found at
native denning sites, (c) Typical haypile found at anthropogenic denning sites. All
photographs by Author (August 2013)
6

My Study and Main Objectives
In this study, I examined the relationship between pikas and the plant communities
present on a landscape that has partially been subject to reclamation activities. My site was
in and around the operating area for Highland Valley Copper mine (HVC) in south-central
British Columbia, Canada. The presence of pikas here is somewhat unusual in that the
operation area is outside of their assumed bioclimatic envelope and a considerable portion of
the population is apparently thriving in waste-rock piles created by mining activity (Blair in
progress, Spilker 2013). Pikas on this landscape site inhabit both native habitat
(undisturbed) and interspersed anthropogenic habitat, the latter being produced by the
reclamation activities of the mine including inhabiting multiple waste-rock piles and roadway
side-cast. This situation provides opportune conditions for investigating how the plant
species hayed compares to what is available to the animals, and how this varies between the
two types of habitats. Essentially, I focused on the comparative use of the plant communities
by pikas in these two habitats. The overarching objective of my project was to determine if
pikas living in the anthropogenic habitat displayed shifts in the plant species they hayed in
comparison to the patterns observed for pikas living in native habitats.
Reclamation studies and project proposals have been underway at HVC since 1970
(Jones and Densmore 1991) with reclamation activities occurring as early as 1984 (Freberg
and Gizikoff 1999) over a large spatial scale. The large size of the mine’s operating area
(approximately 34,000 hectares) and the potential impact it will have on the long-term
ecology of the area has resulted in considerable attention being directed towards reclamation.
This initiative at HVC focuses on converting waste-rock and dump site locations into land
that supports plant communities composed of agronomic and native species (Howie 2008).
Current reclamation projects at HVC include the transformation of a decommissioned
tailings pond into a self-sustaining trout fishery (Hamaguchi et al. 2008) and the mitigation
of several waste rock dumps via the planting of trees, shrubs and grasses via soil
reconditioning by implementing the use of biosolids (Mine Site 2013). Revegetation of the
HVC landscape has now taken place on over 2000 ha of the total disturbed area of 6100 ha
(Jones et al. 1996). Vegetation establishment, tree and shrub survivorship, growth and stock
densities, species composition, foliar nutrient status of forages and biomass production are
7

among the routine assessment and monitoring metrics incorporated into the reclamation and
sustainability initiatives at the mine (Jones et al. 1996).
With the detection of pikas in the anthropogenic reclamated landscape by Howie
(2008), HVC initiated studies into the distribution and ecology of the animals. The initial
work by Howie (2008) reported that the pika population around the mine site was strongly
associated with those locations where waste rock had been dumped. Presumably, the
interstitial spaces provided escape terrain and microsite conditions analogous to what the
animals would use in high-elevation talus habitat, allowing the animals to persevere on the
site. Howie concluded that the retention of the existing pika population on the site would
constitute a “significant contribution to the end land use objectives established for the
reclamation program” (Howie 2008).
A more detailed study on the HVC pikas is currently underway via a partnership
between HVC and Thompson Rivers University (Blair and Larsen, in progress). This work
is focusing on a broad comparison of the demographics and viability of the pika populations
inhabiting the HVC reclamated area and neighboring native habitat. The same population
has been the subject of a smaller study conducted by Spilker (2013), an Honours
undergraduate student, also at Thompson Rivers University. Spilker examined whether the
HVC population of pikas was experiencing environmental temperatures above the supposed
thermal tolerance for the species, and more specifically, whether these conditions differed
significantly between native and anthropogenic habitats. His data indicated that although
extremely warm surface and ambient temperature were present at the HVC site, the pikas
living there were able to avoid them due to the exceptional thermal refuge provided by the
waste rock that functioned as den habitat. Spilker concluded that given these resources, the
pikas would be able to persist in the area, at least under current climate conditions (Spilker
2013).
My study augments the previous and ongoing work by focusing in on the use of the
differing plant communities by pikas living in the anthropogenic HVC landscape and the
adjoining natural habitat.

8

The specific objectives of my study were:


To document and compare plant communities between pikas living in anthropogenic
and native habitat,



To document and compare plant species being hayed by the animals in both types of
habitat and answer the question of whether they are generalists or specialists, and



To assess whether the nutritional content of the plant species occurring in the haypiles
of pikas (in the two different habitats) show significant differences.

MATERIALS AND METHODS
Study Area
Highland Valley Copper is an open-pit mining operation covering approximately
34,000 hectares of land (Mine Site 2013), making it one of the larger copper mining
operations in the world. The mine is located within the Thompson-Nicola region of British
Columbia (Latitude: 50° 28’ N, Longitude: 112° 2’ W), approximately 75 km SW of the city
of Kamloops, British Columbia, Canada.
Undulating mountain ranges, steep gullies and moderate stream channels diversify the
landscape in this region, giving rise to a wide range of plant and animal species. The
operating area encompassed by HVC can be divided into a lower elevation ecotype, with the
dominant overstory vegetation consisting of Douglas-fir (Pseudotsuga menziesii var. glauca),
ponderosa pine (Pinus ponderosa), and trembling aspen (Populus tremuloides), and a higher
elevation ecotype, with the dominant species consisting of lodgepole pine (Pinus contorta),
Englemann-white spruce hybrid (Picea glauca x englemannii) and subalpine fir (Abies
lasiocarpa). These ecotypes correspond to the British Columbia government’s
Biogeoclimatic Ecosystem Classification (BEC) zones of IDFdk1 and MSxk respectively
(Howie 2008, Jones et al. 1996).
The larger concurrent study of Blair and Larsen (in progress) provided detailed
information on the location of occupied pika denning sites in both anthropogenic (reclaimed)
and natural habitat types. These sites ranged from 1446-1841m in elevation and included
9

multiple den sites where pikas had been observed haying. Pikas at each location had been
previously radio collared and ear tagged with a color-coded ear identification tag.
Classification of anthropogenic versus natural habitat was based on rock matrix. All sites
considered ‘anthropogenic’ had been altered physically by mining practices, and had been
subject to vegetation reclamation (Figure 3). Pikas designated as occupying anthropogenic
habitat were found at 7 different den sites throughout the Highland Valley mine operation [3
sites in the Bethlehem area (north of Hwy No. 97C) and 4 sites in the Highmont area (south
of Hwy No. 97C) – see Figure 4]. I also examined pikas from a nearby natural, native
environment. These native sites were essentially untouched and unaltered from their
original, natural state prior to mine construction (Figure 5). This area consisted of 8 different
den sites (i.e. 8 pikas) north of the mine property (all sites were north of Hwy No. 97C)
(Figure 4).

Field Methods
Surveys of the plant communities surrounding each pika den site were conducted
from August 1st to 5th, 2013. To do this, I established 20 m radii plots around each den site,
using a measuring tape, pin flags, and a compass. This radius was determined based on
previous observations/telemetry (Blair and Larsen, in progress) on the maximum distance
traveled by pikas while foraging. Within this plot I recorded all species of vegetation and
assigned each species to a percent cover category (ex. 1-5%, 6-10%, 11-15%, etc.). A
sample of each species was collected and placed into individually-labeled brown paper bags
to later be dried and analyzed for nutritional content (see below), except in situations where
the plant species was deemed too rare for collection. For mosses and lichens, all soil and
root material was removed prior to collection. All above-ground vegetative material for
forbs, shrubs and graminoids was collected. Leaf blades, petioles and stipules were collected
for deciduous tree species and needles were collected for coniferous tree species. All
vegetation samples were subsequently dried in paper bags in a dry, warm (~20°C) location.

10

a

d

b

e

c

f

Figure 3 – Various examples of anthropogenic sites inhabited by the American Pika
(Ochotona princeps) at Highland Valley Copper Mine, British Columbia, Canada; (a)
roadside in Bethlehem, (b) backside of Bose Road dam, (c) waste-rock dump site in
Bethlehem, (d) waste-rock and side cast dump site adjacent to a newly logged cut block in
Highmont, (e) side cast from a road in Highmont, (f) waste-rock dump site in Highmont. All
photographs by Author (August 2013)

11

Figure 4 – 15 study sites at Highland Valley Copper Mine, British Columbia, Canada. Plots
consisted of 5 and 20 m radiuses each. Full location names are in Appendix A. Map
courtesy of Kirby Papineau - GIS Tech, Forsite Consultants Ltd., Kamloops, British
Columbia, Canada
12

Figure 5 – Various examples of natural talus on native sites inhabited by the American Pika
O.princeps adjacent to Highland Valley Copper Mine, British Columbia, Canada. All photographs by
Author (August 2013)

13

I returned on October 10th, 2013 to identify the plant species in those haypiles that I
could detect and access on the pika den sites. As most of this plant material had been stored
deep within the rocks, extraction of the haypile material from within the talus was not
attempted. I inspected the plant material that was accessible by reaching into the haypiles
and uncovering any buried plant species. Plant material examined in this fashion was not
extracted completely to minimize the amount of disturbance. The volume of the haypiles
was estimated using a 4 L container as a reference. Plant species and estimated percent
compositions as a proportion of the volume of each haypile were recorded (see Appendix A).

Sample Preparation for Nutrient Analysis
Once plants were completely dried, I used a new, sterilized commercial coffee grinder
to crush the plant samples (Black & Decker model CBG100S). Each dry sample was
removed from the paper bag by tearing it open along the side. Prior to grinding the plant
samples, larger pieces were cut into smaller portions using a sterilized glass bowl and kitchen
shears. Gloves and tongs were used at all times to handle the plant samples. After each
individual sample was ground, the material was emptied from the hopper into a labeled
plastic zipper-seal bag. All utensils, instruments and the coffee grinder hopper handled using
gloves and re-sterilized between samples using acetone and Kimwipes®. This ensured that
the samples were not contaminated with any other plant material or from chemicals on my
hands.

Laboratory Methods
Each sample was weighed to the nearest milligram in a tin capsule (6 mm x 2.9 mm,
smooth #6703-0418, Exeter Analytical Inc.) using an analytical scale (CP2P-22813971,
Sartorius). The tin capsule was filled approximately three-quarters full with ground plant
material (when tapped on the counter) and the top was pinched closed using forceps. The tin
capsule was then dusted off using a paint brush to clean off any excess plant material that
could have attached to the outside of the capsule.
14

For nutrient analysis, the tin capsules containing the weighed plant samples were
placed into a nickel sleeve (7x5mm, muffled #6703-0499M, Exeter Analytical Inc.),
transferred to a sample wheel (SHA-64 sample wheel with locking pin (large drop hole)
#120-00034, Exeter Analytical Inc.) and analyzed using an automated elemental analyzer
(CE440, Exeter Analytical Inc.). Blanks, standards and conditioners were also analyzed
before and after the plant samples to ensure proper calibration the analyzer. Detailed
information regarding operation and sample run cycles can be found at the Exeter Analytical
Inc. website (http://www.eai1.com/ce440.htm, accessed 2014 January 21) in a manual
entitled “CE440 Principles of Operations Document”. This analysis provided measurements
(in percent) of nitrogen (a component of all amino acids).

Statistical Analysis
I pooled the data collected from each den site within each habitat type (native vs.
anthropogenic), and examined the differences in the most abundant plant species within
vegetative communities and within haypiles. Nutritional analysis data on the plant species
most abundant in the haypile categories were also compared between locations. To
determine the relative abundance of each plant species identified on the denning sites and in
the haypiles, I calculated the average of the abundance categories using the maximum
percent cover (i.e. 1-5% = 5%, 6-10% = 10%, etc.) assigned to the same plant species at each
den site (or in each haypile) and used these numbers to rank relative abundance of the plant
species. Species showing an average abundance above the grand mean abundance value for
all plant species (approximately 3%) were identified as the most abundant species within the
respective location.
Minitab (vers. 16) statistical software was used for comparing the native and
anthropogenic plant communities. A priori tests for normality were run on each group of
data using the Anderson-Darling two sample test, and then I used two-sample t-tests for
independent samples to determine similarity in plant communities between habitat types. I
used the Jaccard index to determine the similarity between plant species diversity of the two
habitat types (Stiling 1999). The Jaccard index is calculated by assigning each plant species
15

a binary value reflecting absence (‘0’) or presence (‘1’) within the plant communities (or
within the haypiles samples). These binary values form a contingency table that is then used
to calculate an index value that ranges between 0 (complete dissimilarity) and 1 (absolute
similarity).

Aspen Leaf Analysis
Observations of pikas collecting fallen, yellow aspen leaves prompted me to also
examine the nutrient level in this plant material along with my other plant samples. In
particular, I compared the harvested yellow leaves with green leaves still on the trees. Both
types of aspen leaves were analyzed for nutritional content to determine if the changes in
nutritional value after the leaves had abscised from the tree.

RESULTS
Plant Community Comparisons
Overall, 89 different plant species were identified within the plots surrounding the
den sites. A total of 40 plant species were found in both categories of habitats, and 35 plant
species were unique to the native sites and 14 plant species were unique to the anthropogenic
sites. An exhaustive list of the common and scientific names of all plant species detected
(both growing and in the haypiles) is presented in Appendix B. Figure 6 shows the
distribution of plant species from both types of habitat listed from most abundant to least
abundant in relation to the native site.
The number of plant species identified in each plant community surrounding
individual den sites is represented in Figure 7. On average, I detected a higher number of
plant species on pika den sites occurring in the native habitat ( = 23.0, SE = 7.5) as
compared to anthropogenic habitat ( = 15.3, SE = 3.0); (T-value = 2.42, CI = 95%, P-value
= 0.036, DF = 10). The Jaccard index also suggested relatively little similarity (J = 0.45).

16

Eleven plant species were considered to be relatively abundant on the native site, and
9 species on the anthropogenic site. Shrubs (woody-stemmed plants) and forbs (broadleafed, non-woody plants) were more likely to overlap between the two types of habitat (i.e.
common juniper, raspberry, strawberry, and thistle). Pinegrass was the only graminoid
deemed ‘abundant’ within both types of habitats. The comparison between most abundant
species in the plant communities of the native and anthropogenic habitats showed relatively
little similarity (J = 0.33; Table 1).

Haypile Comparisons
There were 27 different plant species identified in total across 7 haypiles at the 8
native-habitat den sites. One site had no visible haypiles that could be located during the
October visit. The native haypiles exhibited on average 7.5 different plant species (SE = 2.5)
which ranged from as few as 4 species to as many as 12 species across the den sites (Figure
8). In contrast, the 7 anthropogenic sites had a total of 23 identified species in 7 haypiles, for
an average of 5 species (SE = 1.5) per haypile. The number of species in the anthropogenic
haypiles ranged from 3-7 species (Figure 8).
Of the 27 species identified in the native haypiles, 10 were considered relatively
abundant (Figure 9a). These 10 plant species were composed of three shrubs, two
graminoids, two forbs, one moss and one tree species. Similarly, 10 species were also
identified as relatively abundant in the anthropogenic haypiles (Figure 10a). This group was
composed of three shrubs, three graminoids, three forbs and one tree species. Of the 10 most
abundant native species, 7 species were found in 3 or more haypiles. This varied from the
anthropogenic haypiles in which the majority of the species (8/10) were found in only 1 or 2
haypiles.

17

common juniper
raspberry
strawberry
aspen
horsetail
spruce
thistle
woodsea
black gooseberry
soopalallie
pinegrass
saxifrag
yarrow
one-sided wintergreen
fireweed
alumroot
kinnikinnick
prickly rose
grouseberry
twinflower
lodgepole pine
hair bentgrass
sedge
spiked trisetum
moss
showy daisy
pearly everlasting
dandelion
arctic lupine
mountain arnica
sweet cicely
heart-leaved arnica
bluejoint
chamomile
indian paintbrush
arrow-leaved groundsel
lobelia
willow
white-flowered rhododendron
black twinberry
stonecrop
canadian bunchberry
mullein
sweet scented bedstraw
Parry's arnica
sitka valarian
white hawksbeard
baneberry
alpine speedwell
small flowered penstemon
night-flowering catchfly
white bog orchid
clover
american brooklime
showy aster
few-flowered wintergreen
pink wintergreen
Hobell's rockcress
stinging nettle
northern goldenrod
orange agroserius
saskatoon
rocky mountain juniper
alder
Douglas-fir
foxtail barley
rush
timber oatgrass
timmothy
fescue
wheatgrass
liverwort
dogpelt lichen
cinqfoil
mitrewart
milkvetch
purle-leaved willow heab
large-leaved avens
Menzie's campion
common harebell
spotted saxifrag
unknown purple flower 1
unknown purple flower 2
birch-leaved spirea
huckleberry
broad-leaf grass
cattail
cryptogramic crust
pixie cup lichen

Average percent cover abundance
14

12

10

8

6

4

2

0

12

10

8

6

4

2

0

Figure 6 – Average percent cover plant species abundance across denning sites of the American Pika (Ochotona princeps) in native habitat (top) and anthropogenic habitat (bottom) at Highland Valley Copper Mine, British Columbia,
Canada. The species list on the abscissa consists of the entire assemblage of species identified on both the anthropogenic and native sites. Lack of a bar indicates that the species was not found. (Error bars indicate +/- 1 standard deviation).
An exhaustive list of the common and scientific names of all plant species is presented in Appendix B.

18

Number of plant species

40

30

20

10

0
SFM

FG

BRH

FB

TG

BRCC

BRC

EC

HRN1

SGE

HFG

SGS

BSDE

BBB

BLD

Den Sites
Figure 7 - Number of plant species identified in each plant community surrounding the den sites of the American Pika (Ochotona princeps),
recorded during the summer season (August 1st-5th, 2013), at Highland Valley Copper Mine, British Columbia, Canada. Native sites are illustrated
as gray bars and anthropogenic sites are depicted as patterned bars. The abbreviations on the abscissa are names associated with each site. Site
locations can be identified on the orthographic map (Figure 5) and full site names are listed in Appendix B.

19

Table 1 – Use of the Jaccard index to determine the similarity between the plant communities
surrounding the den sites of American Pikas (Ochotona princeps) between native and anthropogenic
habitats, as recorded during the summer season (August 1st to 5th, 2013), at Highland Valley Copper
Mine, British Columbia, Canada. 1 = present, 0 = not present. Scientific names for plants are provided in
Appendix B.

Abundant Plant Communities
Common Plant
Name

Native

Anthropogenic

aspen

1

0

black gooseberry

1

0

common juniper

1

1

horsetail

1

0

kinnickinick

0

1

lodgepole pine

0

1

pinegrass

1

1

raspberry

1

1

soopalallie

1

0

spruce

1

0

strawberry

1

1

thistle

1

1

willow

0

1

woodsia

1

0

yarrow

0

1

M1,1 = 5
M0,1 = 4
M1,0 = 6

J = 0.33

* Entire native and anthropogenic plant communities (n=89) were also compared using the
Jaccard index which resulted in a J-value of 0.449 (M1,1 = 40, M0,1 = 14, M1,0 = 35)

20

12

Number of plant species

10

8

6

4

2

0
SFM

FG

BRH

FB

TG

BRCC BRC

EC

HRN1 SGE

HFG

SGS

BSDE

BBB

BLD

Den Sites
Figure 8 - Number of identified plant species within each haypile of the native (solid) and anthropogenic (patterned) den sites of the American
Pika (Ochotona princeps) recorded during the fall season (October 10th, 2013) at Highland Valley Copper Mine, British Columbia, Canada

21

Figures 9b and 10b illustrate the average percent composition of each abundant plant
species that composed the native and anthropogenic haypiles, respectively. In both habitat
types (native and anthropogenic), horsetail and soopalallie comprised large proportions of the
haypiles (approximately 20% and 12% respectively). Raspberry on the other hand, although
detected in over two-thirds of the haypiles in both locations, was assigned fairly low
proportional representation in the haypiles (7% and 3% respectively). Pinegrass also was
abundant in both native and anthropogenic haypiles, but the average percent composition
differed between the two locations: in native habitat types, pinegrass comprised
approximately 2% of the haypiles compared to 16% in the anthropogenic haypiles.
My comparison between most abundant species in the native plant communities to the
most abundant species within the haypiles indicated that there was little similarity. The
anthropogenic comparison resulted in even less similarity between the plant community and
the plant species within the haypiles (J = 0.41 and J = 0.27, respectively; Table 2).

Nutritional Analysis
The most abundant species of plants in the haypiles did not tend to be the highest in
nutrition, but rather had average nutritional value in relation to the other plant species
sampled from the surrounding plant community. Nitrogen (N) values for the native and
anthropogenic plant species are illustrated in Figures 11 and 12, respectively. Percent
nitrogen for the native habitat plant species ranged from 0.8% to 4.5%. The most abundant
plant species in the native habitat also had close to average values based on all of the species
present (nitrogen mean = 2.0%) except soopalallie (N = 2.7%) and spiked trisetum (N =
2.5%). The mean percent nitrogen for the haypile species was 1.8%. The nitrogen levels of
the yellow aspen leaves was approximately 1%, whereas the corresponding figures for the
green aspen leaves was approximately 3% (Figure 11).

22

4

3

2

1

Average
percentpercent
value of
species
composition
Average
species
composition

w

e

r

s

s

l

e

0
y

Number
of haypiles in which species were identified
Number of haypiles in which species were identified

a

5

20

b

15

10

5

m

w

tu

ro

se
tri
ed
ik

e
dg

ya
r
sp

m
on
co

m

pi

se

er
ip
ju
n

os
m

s

s
as
ne

al
al
op
so

gr

lie

l
ai
et
rs
ho

be
sp
ra

as

pe

n

rry

0

Figure 9 - Most abundant species identified in the haypiles of native den sites of the American
Pika (Ochotona princeps). Figure 9 (a) shows the number of den sites where the plant species
were detected, whereas 9 (b) depicts the average percent volume that each species appeared in
the haypiles. Data collected on October 10th, 2013 at Highland Valley Copper Mine, British
Columbia, Canada.
23

4

3

2

1

0
l

Number of haypiles in which species were identified

Number of haypiles in which species were identified

a

5

Average
percentpercent
value of
species
composition
Average
species
composition

20

b
15

10

5

pu
ss
yt
oe
s

th
is
tle
lo
dg
ep
ol
e
pi
br
ne
oa
dle
af
gr
as
sp
s
ik
ed
tri
se
tu
m

w
illo
w

ho
rs
et
ai
l
so
op
al
al
lie

pi
ne
gr
as
s
ra
sp
be
rry

0

Figure 10 - Most abundant species identified in the haypiles of anthropogenic den sites of the
American Pika (Ochotona princeps). Figure 10 (a) shows the number of den sites where the
plant species were detected, whereas Figure 10 (b) depicts the average percent volume that each
species appeared in the haypiles of the pikas. Data collected on October 10th, 2013 at Highland
Valley Copper Mine, British Columbia, Canada.
24

Table 2 – Comparison of the relatively abundant plant species in the vegetation communities
surrounding pika denning sites with those in the animals’ haypiles. Binary values represent
presence (1) and absence (0) of the plant species. Jaccard’s index (J-values) indicate relatively
little similarity between the two groups of plants. For scientific names of the plant species see
Appendix B.
Native

Anthropogenic

Plant
Community

Within
Haypile

Abundant Species

Plant
Community

Within
Haypile

aspen

1

1

birch-leaved spirea

1

0

black gooseberry

1

0

broad-leaf grass

0

1

common juniper

1

1

common juniper

1

0

horsetail

1

1

horsetail

0

1

moss

0

1

kinnickinick

1

0

pinegrass

1

1

lodgepole pine

1

1

prickly rose

1

0

pinegrass

1

1

raspberry

1

1

pussytoes

0

1

sedge

0

1

raspberry

1

1

soopalallie

1

1

soopalallie

0

1

spiked trisetum

0

1

spiked trisetum

0

1

spruce

1

0

strawberry

1

0

strawberry

1

0

thistle

0

1

thistle

1

0

willow

1

1

willow

1

0

yarrow

1

0

woodsia

1

0

yarrow

1

1

Abundant Species

M1,1 = 7

M1,1 = 4

M0,1 = 3

M0,1 = 6

M1,0 = 7

J = 0.412

M1,0 = 5

25

J = 0.267

lodgepole pine
rocky mountain juniper
spruce
yellow aspen
green aspen
alder
willow
black twinberry
common juniper
grouseberry
prickly rose
raspberry
saskatoon
soopalalli
alpine speedwell
american brooklime
arctic lupine
arrow leaved groundsel
baneberry
green wintergreen
indian paintbrush
lobelia
milkvetch
mitrewart
mullein
nodding saxifrag
northern goldenrod
pearly everlasting
pink wintergreen
pussytoes
showy daisy
sitka valerian
stinging nettle
strawberry
thistle
twinflower
yarrow
foxtail barley
pinegrass
sedge
spiked trisetum
dogpelt
horsetail
liverwort
moss
woodsea

Nitrogen Content (%)
5

4

3

2

1

0

Figure 11 – Nitrogen analysis outputs for 46 species collected during the summer season (August 1st-5th, 2013) from native 20m plot
locations at Highland Valley Copper Mine, Logan Lake, British Columbia, Canada. Most abundant species identified as comprising
portions of native haypiles of the American Pika (Ochotona princeps) are indicated by dark gray bars. The species list on the abscissa
is listed alphabetically in order of functional groups as depicted in Appendix B.
26

27

pixiecup lichen

horsetail

spiked trisetum

sedge

rush

pinegrass

hair bentgrass

broadleaf grass

bluejoint

yarrow

thistle

sweet scented bedstraw

stonecrop

strawberry

pussytoes

pearly everlasting

one-sided wintergreen

nodding saxifrag

mullein

Menzie's campion

lobelia

large leaved avens

common harebell

cinqfoil

canadian bunchberry

white flowered rhododendron

soopalalli

raspberry

prickly rose

kinnikinnick

huckleberry

grouseberry

common juniper

black twinberry

black gooseberry

birch leaved spirea

willow

alder

lodgepole pine

Nitrogen Content (%)
5

4

3

2

1

0

Figure 12 - Nitrogen analysis outputs for 39 species collected during the summer season (August 1st-5th, 2013) from 7 anthropogenic
20m plot locations at Highland Valley Copper Mine, Logan Lake, British Columbia, Canada. Most abundant species identified as
comprising portions of native haypiles of the American Pika (Ochotona princeps) are indicated by dark gray bars. The species list on
the abscissa is listed alphabetically in order of functional groups as depicted in Appendix B.

Percent nitrogen for the plants in the anthropogenic habitat ranged from 0.8% to 3.9%. In
the anthropogenic habitat, three shrubs (see below) were above the average nutrient percent
content (nitrogen mean = 1.7%); willow (N = 2.5%), raspberry (N = 1.9%) and soopalallie (N =
2.8%). There were 2 of the 3 forbs that also were above the average nutrient percent content,
yarrow (N = 1.9%) and thistle (N = 2.4%) while the rest of the most abundant haypile species
were below the mean (Figure 12).
Plants from both locations with the highest nutritional values of nitrogen (milkvetch and
stinging nettle in native communities - Figure 11; alder and Menzie’s campion in anthropogenic
communities - Figure 12) were not species considered abundant within the respective haypiles.
These four plant species were considered relatively rare within their respective plant
communities (refer back to Figure 6).

DISCUSSION
To summarize, the main results of my study were:


Native and anthropogenic plant communities surrounding the pika den sites showed little
similarity in terms of species diversity; this was the case when I compared the entire plant
communities (i.e. all species of plants detected) or narrowed the comparison down to just
the most abundant species within each location which verified that native plant
communities were much more diverse in species richness than the contrasting
anthropogenic habitat.



Species identified as most abundant within the haypiles were not necessarily the most
abundant species of the corresponding native or anthropogenic plant communities, and
consisted primarily of shrubs, forbs and graminoids.



The mean nutritional content of the plant species occurring in the haypiles of the two
different habitats was similar, suggesting the animals in either habitat category have
access to plants of similar nutritional value.

28

Plant Community and Species Diversity
The results of this portion of my study suggest that pikas occupying the anthropogenic
habitat at denning sites are using plant vegetation communities reasonably dissimilar from
neighbouring pikas living in native habitat. The lack of similarity between the native and
anthropogenic sites is not unexpected: ecosystems altered by human activity generally do not
revert to the original native habitat, in terms of species richness (number of individual species)
and species evenness (relative abundance of those species) as a result of alterations to the
community structure (Kimmins 2004).
The dissimilarity of plant communities in my study site may be partially due to the fact
reclamation efforts do not necessarily aim to re-establish original habitat characteristics (i.e.
original habitat community structure) (Hingtgen and Clark 1984). For example, reclamation
obligations at HVC involve the development of a self-sustaining vegetation cover to offset the
various disturbances, by using a combination of agricultural and native species. An outcome of
waste rock dump and tailings areas reclamation is the creation of shrubland units that provides a
primary source of browse and thermal and visual cover for small mammals and other wildlife
species. Understory species that are suggested to be planted include crested wheatgrass, red
fescue, pubescent wheatgrass, aspen, balsam, willow, rose, saskatoon and sage. High-elevation
regions will be subject to the planting of various tree species such as lodgepole pine, Douglas-fir
and interior spruce (Freberg and Gizikoff 1999).
The change in plant community structure as a result of reclamation efforts offers its own
unique habitat features (Kimmins 2004), and although these proposed species meet the
reclamation prescription required to achieve the mine’s end land use goals, they create a
contrasting habitat for native, small herbivorous mammals. However, these altered plant
communities provided the backdrop for this study. In this case, they help to reveal the plasticity
of pika foraging behaviour to resource availability, especially interesting given that the animal is
considered a ‘specialist species’ (Varner and Dearing 2014).
Although the plant communities in the two habitats I studied were dissimilar in terms of
the species assemblages, my data revealed there was consistency in the types of plants that were
most abundant in the two habitats: shrubs and forbs were common in both habitats. The
differences in the plant community that I detected in this study may also be attributable to factors
29

other than simply the species selected for planting in the anthropogenic habitat. There is a large
suite of factors that will affect the growth and succession of various plants, influencing
productivity levels of the habitat itself (Hingtgen and Clark 1984), including the natural
dispersion of native plant species causing re-establishment within the anthropogenic area.
Temperature, sunlight exposure and soil moisture and soil nutrient regimes were variables not
measured in this study however, should be taken into consideration in future research focusing
on these contrasting habitats at Highland Valley Copper Mine.

Plant Community and Haypiles
Pika haypiles did not strongly reflect those plant species most abundant within the habitat
surrounding their den sites (anthropogenic or native). The data supports the more recent
suggestion that pikas are selective in terms of the vegetation they hay (Varner and Dearing
2014). Although the native and anthropogenic locations differed in the total number of plants
present, the numbers of plants observed in the haypiles were relatively close in number to one
another. Shrubs and forbs composed the majority of the pika haypiles, which is suggested to be
a method used by pikas to maximize the amount of vegetation stored per unit of energy spent, as
opposed to graminoids, mosses or lichens which may provide adequate nutritional value but have
less above-ground vegetative material (Gliwicz et al. 2006).
My data also suggest that the pikas in the native sites are haying a more diverse array of
plant material in comparison to their conspecifics in the anthropogenic sites. One simple
explanation is that there may be a greater number of native plants that meet nutritional criteria of
the pikas. Therefore, the broad usage of plant species by the pikas within the native plant
communities could reflect a strategy for obtaining required nutrients via the mixing or balancing
of diet forage (Cameron et al. 2009, Varner and Dearing 2014). Similar to the pika, the Hispid
Cotton Rat (Sigmodon hispidus) demonstrates selective foraging behaviour to obtain necessary
nutrients (Cameron et al. 2009). That study suggested that the rats were consuming forage of
mixed plant species that individually did not provide the highest possible nutritional value, but
instead resulted in a balance of their nutrient intake. Another theory to explain the broader
selection of plants by pikas in native habitat is that there were more species meeting nutrition
30

criteria within close proximity to the den sites (as compared to the anthropogenic habitat). This
would minimize the time travelling further from the dens and exposure to predators (Morrison et
al. 2004). This implies a possible cost to living in anthropogenic habitat, namely less canopy and
ground cover, and hence increased exposure. Yet another possible explanation for forage
selectivity by pikas in this study could be competition from yellow-bellied marmots (Marmota
flaviventris), which are quite common within the anthropogenic habitat (pers.observ.). Diet
overlap in these two animals could result in pikas altering their food selection, as a result of a
trade-off between the value of food items and the probability of aggressive competition
(Morrison et al. (2004). My ability to speculate on these possible explanations is very limited, as
collecting data on foraging behaviour (e.g. foraging distances for different plant species,
predation risk, competition with other small mammals, etc.) was well beyond the scope of my
study.

Haypiles and Nutrition
The nitrogen content of plants is one of the many nutritional qualities that are essential to
herbivores (Mattson 1980). Due to its vital role in animal metabolism and proteins for structural
building-blocks, herbivores often respond positively to nitrogen content of forage species, as
levels of this nutrient are generally low in plant material (Mattson 1980, Kimmins 2004).
However, forbs, ferns and shrubs show significantly higher nitrogen content in comparison to
mosses, lichens and deciduous tree species (Dubay et al. 2008, Varner and Dearing 2014). My
results revealed that pikas were primarily caching shrubs and forbs, which suggests that the
animals were harvesting plant species exhibiting average nitrogen levels, and therefore not
targeting plants that are high in nitrogen as a nutritional value. This was further supported by the
yellow aspen leaves being hayed by the native pikas as opposed to the highly nutritional green
aspen leaves. Results indicated that the nutritional levels of the aspen leaves decreased as the
leaf changed color from green to yellow, explainable by the process of autumn leaf senescence.
The lower percentage of nitrogen in the yellow aspen leaves is indicative of deciduous trees,
which retranslocate the leaf nutrients prior to abscission (Kimmins 2004).

31

Examination of the nutritional value of plant species present in the haypiles of the two
contrasting habitats did not reveal striking differences between the native and anthropogenic
habitat types. There was a greater range in the nitrogen content of the plant species detected in
the native habitat. This may be due to the fact that this plant community had a greater range of
species. Admittedly, my sample sizes are not large, and my haypile sampling period was very
truncated. A more elaborate study would allow for haypile sampling over a longer period in
autumn (along with focal observations on pika foraging). The pikas at HVC show haying
behaviour throughout mid-July to the onset of winter (Blair, pers. comm.), so whether my
samples reflect the plants harvested by the animals over this entire time period is unknown at the
present time.
The importance of nitrogen diets in the diet of Snowshoe Hares (Lepus americanus) was
proposed by Sinclair et al. (1982). They determined the percent crude protein threshold
estimates for Snowshoe Hares in a laboratory study conducted within environmental chambers at
the Small Mammal Research Facility of the University of British Columbia. Similar to the pika
living in anthropogenic habitat, the Snowshoe Hares were subjected to differing diet conditions
[high-quality forage (high percentage of crude protein) and low-quality forage (low percentage
of crude protein)] throughout winter months over a 2 year period. They determined that the
hares in their study population required a diet of at least 11% crude protein [a minimum of
1.76% nitrogen, determined by converting crude protein estimates using a constant of 6.25
(Kyriazakis and Oldham 1993)] or else weight loss occurred and the risk of mortality increased.
In the present study, pikas in the native habitat are haying plant species that have an average
nitrogen value of 2.016%, greater than the minimum requirement identified for Snowshoe Hares.
The pikas in the anthropogenic habitat however, are only obtaining an average nitrogen value of
1.696% from the plant species within their haypiles. This would indicate that, if nitrogen
requirements for the Snowshoe Hare are similar to that of the American Pika, then the pika
would be obtaining nitrogen values 0.064% less than the Snowshoe Hare’s suggested nitrogen
requirements. As this is an appreciably small percent difference, there may possibly be no
impact to the pikas weight or survivorship. However, I cannot make any definitive comments on
body weights or survival across the two habitat types, although such data are forthcoming (Blair
and Larsen, in progress).

32

Many herbivorous species prefer diets with high nitrogen content; however, such
foodstuffs may not always be present, and other nutrients may also need to be accounted for
when foraging for foodstuff (Dubay et al. 2008). Dubay et al. (2008) determined that Southern
Red-Backed Voles (Clethrionomys gapperi) preferred forage such as hypogenous fungus that
was high in nitrogen, whereas the Northern Flying Squirrel (Glaucomys sabrinus) preferred a
fungus that was equally high in potassium, phosphorus and nitrogen. Many small mammals
seem to be able to balance their dietary nitrogen requirements in the presence of low-nitrogen
forage within the plant community. Felicetti et al. (2000) determined that the North American
Porcupine (Erethizon dorsatum) was able to achieve nitrogen balances even in conditions where
low levels of nitrogen were being consumed. Dearing et al. (2005) also came to this conclusion
when they studied the response of Bushy-tailed Woodrats (Neotoma cinerea) to forage with lownitrogen compositions. These studies support my conclusion that pikas in the anthropogenic
habitat at HVC are likely able to obtain forage that meets their nutritional requirements, at least
in terms of nitrogen, even though their surrounding plant community is considerably different
from that found in the neighbouring natural area. Furthermore, Spilker (2013) determined that
anthropogenic rock habitat at the HVC site provides comparable temperatures to that of natural
talus habitat. Therefore, the combined results of that study and the present one suggest that pikas
inhabiting anthropogenic habitat at HVC are at little or no disadvantage in comparison to pikas
in native habitats, in terms of the parameters measured. The concurrent study (Blair and Larsen,
in progress) along with future work will help further clarify this pattern.
This study provides the first data on the nutritional composition of plants found within
the haypiles of American Pikas in British Columbia. My inability to access the entire contents of
the haypiles made it impossible to precisely quantify important variables such as haypile volume,
size of the haypile (both wet and dry weight) and estimates of haypile plant compositions. This
forced me to limit my nutritional analysis to only the plants that were visible, which may have
been only the most recently harvested vegetation (as plants harvested earlier may have been
already dried and already cached well below the surface). From the plant material that I was able
to collect and analyze, I determined that pikas did not appear to be haying specific plant species
that had relatively high nutritional values, but they do seem to be haying specific types of plants,
such as shrubs and forbs. The average nutritional values calculated from those plants most

33

abundant in the haypiles supports an assertion that the pikas are obtaining the same or similar
nutrients regardless of which habitat they occupy, due in part to their specialist forage
requirements.
Although measurements of nitrogen and crude protein are exceptionally important to the
health of an animal, more elaborate analysis could include estimates of fiber, energy, phenolic
(antioxidant compound levels) content, as well as important mineral elements such as calcium,
potassium, sodium, zinc and iron. Again, obtaining these data were well beyond the scope of
this study, but may be considered for more elaborate, future work into the diet of these animals.
Trends in my results would have been further supported if I were able to incorporate
survivorship studies, thus determining whether or not the forage was sufficient in terms of
providing enough nutrients to sustain individuals all winter. Ultimately, my study provides only
a snapshot of information on the overwinter diet of these animals. It is important that this
information be considered in tandem with forthcoming data on body size, foraging behaviour,
survival and reproduction (Blair and Larsen, in progress).

CONCLUSION
In conclusion, this study provides a foundation for further work examining how pikas
respond to anthropogenic habitats particularly as it relates to their use of plants during the haying
period. This in turn suggests that anthropogenic alterations to plant communities do not greatly
impact the haying activities of this small herbivorous mammal. Within the scope of my study,
negative effects stemming from the harvest of plants from the anthropogenic plant community
were not detectable, although further investigation is required. Nonetheless, this study reveals an
apparent malleability of pika haying behaviour (i.e. plant use) across neighbouring but
contrasting habitats. This study should contribute to a better understanding of the ecology of the
pikas in the HVC site, and in doing so, facilitate their persistence on the landscape.

34

LITERATURE CITED
Apps CD, McLellan BN, Woods JG, Proctor MF. 2004. Estimating Grizzly Bear distribution
and abundance relative to habitat and human influence. Journal of Wildlife Management,
68(1): 138-152
Battin J. 2004. When good animals love bad habitats: Ecological traps and the conservation of
animal populations. Conservation Biology, 18(6):1482-1491
Beever E, Smith AT. 2011. Ochotona princeps. In: IUCN 2013. IUCN Red List of Threatened
Species. Version 2013.2. [Internet]. [cited 2014 January 24]. Available from:
www.iucnredlist.org
Bender DJ, Contreras TA, Fahrig L. 1998. Habitat loss and population decline: A metaanalysis of the patch size effect. Ecology, 79(2): 517-533
Blair C. in progress. Comparative ecology of pika (Ochotona princeps) in anthropogenic and
native habitat. Unpublished MSc thesis, Thompson Rivers University, Kamloops, British
Columbia, Canada
Cameron GN, Johnston JJ, Randolph JC. 2009. Nutrient encounter by a generalist herbivore in
a heterogeneous landscape. American Midland Naturalist, 161(2): 243-250
Conner DA. 1983. Seasonal changes in activity patterns and the adaptive value of haying in
pikas (Ochotona princeps). Canadian Journal of Zoology, 61: 411-416
Dearing MD. 1996. Disparate determinants of summer and winter diet selection of a generalist
herbivore, Ochotona princeps. Oecologia, 108(3): 467-478
Dearing MD. 1997. The function of haypiles of pikas (Ochotona princeps). Journal of
Mammalogy, 78(4): 1156-1163
Dearing MD, McLister JD, Sorensen JS. 2005. Woodrat (Neotoma) herbivores maintain
nitrogen balance on a low-nitrogen, high-phenolic forage, Juniperus monosperma.
Journal of Comparative Physiology B, 175(5): 349-355
DeGabriel JL, Wallis IR, Moore BD, Foley WJ. 2008. A simple, integrative assay to quantify
nutritional quality of browses for herbivores. Oecologia, 156: 107-116
Dubay SA, Hayward GD, Martinez del Rio C. 2008. Nutritional value and diet preference of
arboreal lichens and hopogeous fungi for small mammals in the Rocky Mountains.
Canadian Journal of Zoology, 86: 851-862

35

Felicetti LA, Shipley LA, Witmer GW, Robbins CT. 2000. Digestibility, nitrogen excretion,
and mean retention time by North American Porcupines (Erethizon dorsatum) consuming
natural forages. Physiological and Biochemical Zoology, 73(6): 772-780
Freberg MR, Gizikoff KG. 1999. Development and utilization of an end land use plan for
Highland Valley Copper. The Technical and Research Committee on Reclamation –
Preceedings of the 23rd annual British Columbia Mine Reclamations Symposium in
Kamloops. [Internet]. [cited 2014 February 21]; Available from:
http://www.trcr.bc.ca/wp-content/uploads/2011/11/2000-freberg-gizikof.pdf
Gliwicz J, Pagacz S, Witczuk J. 2006. Strategy of food plant selection in the Siberian Northern
Pika, Ochotona hyperborean. INSTAAR, University of Colorado Arctic, Antarctic and
Alpine Research, 38(1): 54-59
Hamaguchi BA, Larratt HM, Freberg M. 2008. The development of an aquatic ecosystem in
Trojan tailings pond, Highland Valley Copper. British Columbia Technical and Research
Committee on Reclamation. UBC cIRcle. [Internet]. [cited 2014 January 29]; Available
from:
https://circle.ubc.ca/bitstream/handle/2429/8290/17Larratt%20Paper.pdf?sequence=1
Hampton RE, Havel JE. 2006. Introductory biological statistics, Second Edition. Long Grove
(IL), Waveland Press, Inc. 175p
Hingtgen TM, Clark WR. 1984. Impact of small mammals on the vegetation of reclaimed land in
the northern great plains. Journal of Range Management, 37(5): 438-441
Hovland N, Andreassen HP, Ims RA. 1999. Foraging behaviour of the root vole Microtus
oeconomus in fragmented habitats. Oecologia, 121(2): 236-244
Howie R. 2008. Distribution and habitat associations of the American pika (Ochotona princeps)
in the Highland Valley Copper Mine operating area. 2007 Annual Reclamation Report –
Aspen Park Consulting, 3(8)
Hunter P. 2007. The human impact on biological diversity – How species adapt to urban
challenges sheds light on evolution and provides clues about conservation. European
Molecular Biology Organization reports, 8(4): 316-318
Huntly NJ, Smith AT, Irvins BL. 1986. Foraging behaviour of the pika (Ochotona princeps),
with comparisons of grazing versus haying. Journal of Mammalogy , 67: 139-148

36

Jones CE, Densmore HB. 1991. Through conceptual planning to sustainable landscapes at
Highland Valley Copper. B.C. Mine Reclamation Symposium. UBC cIRcle. [Internet].
[cited 2014 February 25]. Available from:
https://circle.ubc.ca/bitstream/handle/2429/12535/1991%20%20Jones%2c%20Densmore%20%20Through%20Conceptual%20Planning.pdf?sequence=1

Jones CE, Freberg M, Hamaguchi R, Straker J. 1996. Reclamation research and monitoring at
Highland Valley Copper. B.C. Mine Reclamation Symposium. UBC cIRcle. [Internet].
[cited 2014 January 29]. Available from:
https://circle.ubc.ca/bitstream/handle/2429/9011/01%20Jones.pdf?sequence=1
Kimmins JP. 2004. Forest Ecology: A foundation for sustainable forest management and
environmental ethics in forestry, Third Edition. Upper Saddle River (NJ), Pearson
Prentice Hall. 611p
Kyriazakis I, Oldham JD. 1993. Diet selection in sheep: the ability of growing lambs to select a
diet that meets their crude protein (nitrogen x 6.25) requirements. British Journal of
Nutrition, 69(3): 617-629
Manning T, Hagar JC. 2011. Use of nonalpine anthropogenic habitats by American pikas
(Ochotona princeps) in Western Oregon. Western North American Naturalist, 71(1):
106-112
Mattson WJ, Jr. 1980. Herbivory in relation to plant nitrogen content. Ann. Rev. Ecol. Syst., 11:
119-161
Mine Sites. Major Mining Operations Around the World - Highland Valley Copper Mine.
[Internet]. Vancouver, BC: Info Mine – Mining Intelligence and Technology [cited 2013
October 5]. Available from http://www.infomine.com/minesite/minesite.asp?site=hvc
Ministry of Energy, Mines and Petroleum Resources - Mining and Minerals Division. 2008.
Health, Safety and Reclamation Code for Mines in British Columbia. Victoria, British
Columbia. [Internet]. [cited 29 January 2014]. Available from:
http://www.empr.gov.bc.ca/mining/healthandsafety/documents/hsrc2008.pdf
Morrison ML, Marcot BG, Mannan RW. 2006. Wildlife-Habitat Relationships: Concepts and
Applications, Third Edition. Washington (DC), Island Press. 493p
Parish R, Coupé R, Lloyd D. 1996. Plants of southern interior British Columbia and the inland
northwest. China, B.C. Ministry of Forests and Lone Pine Publishing. 463p
Sinclair ARE, Krebs C, Smnith NM. 1982. Diet quality and food limitation in herbivores: the
case of the snowshoe hare. Canadian Journal of Zoology, 60: 889-897
37

Spilker E. 2013. Temperature-habitat relationships of the American pika (Ochotona princeps)
in an atypical environment. Unpublished Honors thesis, Thompson Rivers University,
Kamloops, British Columbia, Canada
Stiling P. 1999. Ecology: Theories and Applications, Third Edition. Upper Saddle River (NJ),
Prentice Hall. 614p
Swank C. 2004. Molybdenosis – Are moose at risk at highland valley copper? Unpublished MSc
thesis, University College of the Cariboo, Kamloops, British Columbia, Canada
Varner J, Dearing MD. 2014. Dietary plasticity in pikas as a strategy for atypical resource
landscapes. Journal of Mammalogy, 95(1): 72-81

38

APPENDIX A
Table 3 – Codes identifying locations of American Pika (Ochotona princeps) in the Highland Valley Copper Mine operating area
(anthropogenic habitat) and adjacent native habitat, including detailed site information, 2013

Site Identification

Abbreviation
of Site ID

Coordinates
(Northing,
Easting)

BEC Zone

Aspect

Slope
(%)

Estimated
Size of
Visible
Haypile

1831
1765
1490
1701
1622
1449
1481
1476

NE
WSW
SW
E
W
SE
SSW
SE

+52
+84
+70
+71
+63
+69
+60
+74

12 L
21 L
6L
14L
None Visible
7L
16 L
16 L

1510
1567
1496
1531
1446
1519
1522

NW
ESE
E
S
NE
NE

+54
+70
+70
+84
+70
+47
+57

6L
7L
6L
8L
20 L
12 L
5L

Elevation
(m)

Native Habitat Type
South Forge Mountain
Forge Gully
Bose Road Horseshoe
Forge Bluffs
Truck Gully
Bose Road Clear-Cut
Bose Road Culvert
Eve’s Canyon

SFM
FG
BRH
FB
TG
BRCC
BRC
EC

5601161, 0640658
5603811, 0641328
5599673, 0643155
5604169, 0641736
5601832, 0642347
5599678, 0644606
5599451, 0642963
5598014, 0640463

ESSF xc2
MS xk2
MS xk2
MS xk2
MS xk2
MS xk2
MS xk2
MS xk2

Anthropogenic Habitat Type
Highmont Road North 1
Shop Gully East
Highmont Fork Gully
Shop Gully South
Bethlehem South Dumps East
Bethlehem Blind Berm
Bose Lake Dam

HRN1
SGE
HFG
SGS
BSDE
BBB
BLD

5589356, 0645562
5589782, 0642211
5589012, 0646083
5589738, 0641724
5594469, 0643973
5595416, 0643699
5597796, 0643708
39

MS xk2
MS xk2
MS xk2
MS xk2
IDF dk1
MS xk2
MS xk2

APPENDIX B
Table 4 – Vegetation observed near sites occupied by American Pika (Ochotona princeps) in
the Highland Valley Copper Mine operating area (anthropogenic habitat) and adjacent native
habitat, 2013
Common Name

Scientific Name

Detected in
Haypile

Native

Anthro

Pseudotsuga menzesii var. glauca
Pinus contorta var. latifolia
Juniperus scopulorum
Picea glauca x engelmannii

✔
✔
✔
✔

✔
✔

✔

✔
✔

✔

✔

✔

Populus tremuloides
Alnus incana ssp. Tenuifolia
Salix spp.

✔
✔
✔

Trees (Coniferous)
Douglas-fir
Lodgepole pine
Rocky mountain juniper
Spruce

Location

Native Anthro

Trees (Deciduous)
Aspen
Alder
Willow

✔
✔
✔

✔
✔

✔
✔
✔
✔
✔
✔
✔
✔
✔

✔

Shrubs
Birch-leaved spirea
Black gooseberry
Black twinberry
Common juniper
Grouseberry
Huckleberry
Kinnikinnick
Prickly rose
Raspberry
Saskatoon
Soopalallie
White-flowered
rhododendron

Spiraea betulifolia
Ribes lacustre
Lonicera involucrate
Juniperus communis
Vaccinium scoparium
Vaccinium membranaceum
Arctostaphylos uva-ursi
Rosa acicularis
Rubus idaeus
Amelanchier alnifolia
Shepherdia canadensis

✔
✔
✔
✔
✔
✔
✔
✔
✔

Rhododendron albiflorum

✔

Veronica wormskjoldii
Heuchera cylindrical
Veronica Americana
Lupinus arcticus
Senecio triangularis
Actaea rubra

✔
✔
✔
✔
✔
✔

✔
✔
✔

✔

✔
✔
✔

✔

✔

✔

✔

✔

Forbs
Alpine speedwell
Alumroot
American brooklime
Arctic lupine
Arrow-leaved groundsel
Baneberry

40

✔

✔
✔

Canadian bunchberry
Chamomile
Cinqfoil
Clover
Common harebell
Dandelion
Fireweed
Green wintergreen
Heart-leaved arnica
Holboell’s rockcress
Indian paintbrush
Large-leaved avens
Lobelia
Menzie’s campion
Milkvetch
Mitrewart
Mountain arnica
Mullein
Night-flowering
catchfly
Nodding saxifrage
Northern goldenrod
One-sided wintergreen
Orange agoseris
Parry’s arnica
Pearly everlasting
Pink wintergreen
Purple-leaved willow
herb
Pussytoes
Showy aster
Showy daisy
Sitka valerian
Small flowered
penstemon
Spotted saxifrage
Stinging nettle
Strawberry
Stonecrop

Cornus canadensis
Matricaria recutita
Potentilla recta
Trifolium pretense and Trifolium
hybridum
Campanula rotundifolia
Taraxacum officinale
Epilobium angustifolium
Pyrola chlorantha
Arnica cordifolia
Arabis holboellii
Castilleja miniata
Geum macrophyllum
Lobelia kalmia
Silene menziesii
Astragalus miser
Mitella nuda
Arnica latifolia
Verbascum Thapsus

✔
✔

Silene noctiflora

✔

Saxifraga cernua
Solidago multiradiata
Pyrola segunda
Agoseris aurantiaca
Arnica parryi
Anaphalis margaritacea
Pyrola asarifolia

✔
✔
✔
✔
✔
✔
✔

✔
✔
✔

✔
✔
✔
✔
✔
✔
✔

✔
✔
✔

✔
✔

✔
✔
✔
✔
✔
✔

✔

✔

✔
✔

Antennaria spp.
Aster conspicuous
Erigeron speciosus var. speciosus
Valeriana sitchensis

✔
✔
✔
✔

Penstemon procerus

✔
✔
✔
✔

41

✔

✔

Epilobium ciliatum

Saxifraga bronchialis
Urtica dioica
Fragaria virginiana
Sedum lanceolatum

✔

✔

✔

✔
✔
✔

✔

✔

✔

✔
✔

✔

Sweet cicely
Sweet scented bedstraw
Thistle
Twinflower
White bog orchid
White hawkweed
Yarrow

Osmorhiza chilensis
Galium triflorum
Cirsium spp.
Linnaea borealis
Platanthera dilatata
Heiracium albiflorum
Achillea millefolium

✔
✔
✔
✔
✔
✔
✔

Calamagrostis canadensis
Agrostis gigantea
Typha latifolia
Festuca spp.
Hordeum jubatum
Agrostis scabra
Calamagrostis rubescens
Juncus spp.
Carex spp.
Trisetum spicatum
Danthonia intermedia
Phleum pretense
Agropyron spp.

✔

✔
✔
✔

✔

✔

✔

✔

Graminoids
Bluejoint
Broad-leaf grass
Cattail
Fescue
Foxtail barley
Hair bentgrass
Pinegrass
Rush
Sedge
Spiked trisetum
Timber oatgrass
Timothy
Wheatgrass

✔
✔
✔

✔
✔
✔
✔
✔
✔
✔
✔
✔
✔

✔
✔

✔
✔
✔
✔
✔
✔
✔

✔
✔

✔
✔

✔
✔

Ferns, Horsetails, Mosses and Lichens
Cryptogramic crust
Dogpelt lichen
Horsetail
Liverwort
Moss
Pixie Cup lichen
Woodsia

✔
Peltigera canina
Equisetum arvense
Marchantia polymorpha
Cladonia pyxidata
Woodsia scopulina

✔
✔
✔
✔
✔

42

✔
✔
✔

✔
✔
✔
✔
✔

✔