Wolf Inventory in the North Thompson
Valley, British Columbia
Prepared By:
Doug Lewis 1 and Cory Eustache 2
Prepared For:
Simpcw Development Corporation
1
Forest Insight Consulting. Kamloops, BC. (250) 828-0676. [email protected]
2
North Thompson Indian Band and Integrated Woods Services Ltd. Kamloops,
BC. (250) 377-5308. [email protected]
Acknowledgements
Forest Investment Account provided funding for this project through the
auspices of Simpcw Development Corporation. Special Thanks to Steve
Henderson of Integrated Woods Services for project support.
i
Summary
Predation has been identified as the proximate cause of decline in
threatened and endangered populations of the mountain ecotype of
woodland caribou (Rangifer tarandus caribou) in British Columbia
(Wittmer et al. 2005). While predation is believed to come from several
sources, recent attention has focused on wolves due to a suspected
increase in wolf populations as a response to higher moose densities
(Stotyn et al. 2005). Greater wolf numbers are believed to increase the
likelihood of wolves encountering caribou during spring, summer and
early winter seasons when their ranges can overlap, leading to possibly
higher predation rates (Seip 1992, Stotyn et al. 2005, Wittmer et al.
2005).
In the North Thompson valley almost no information currently exists on
wolves and their relationships with caribou populations. The goal of our
project was to establish the presence of wolves and assist in the capture
and radio collaring of wolves to allow for further study. We used scat and
track surveys (Resource Inventory Standards Committee Inventory
Methods for Wolf and Cougar, Version 2.0, June 1998) and howling
surveys to establish the presence of wolves. We further assisted in
establishing and monitoring of traps, live trapping, and radio collaring of
wolves.
The scat and track surveys proved to be a successful method to establish
the presence of wolves. We identified two spatially separated, distinct
wolf packs of an estimated 10-12 animals each, including pups, in the
study area. Consistent surveys of roads over a period of seven weeks
from July 11- September 01, 2005, suggested these wolf packs remained
relatively cohesive and stationary during this period, although individual
animals likely traveled greater distances. The northern pack
(Serpentine\Albreda) remained at lower elevations (mainly < 1000 metres
elevation) in predominantly ICH forests, while the southern pack
(Berry\Raft) used higher elevation ESSF forest habitats during this same
time, although they remained spatially separated from known caribou
calving and summer habitats. We hypothesize that differences in
elevational use by wolves between the two groups may be associated with
seasonal movements of prey (mainly moose), topography, logging history
and road density.
The howling surveys proved to be much less successful than scat and
track surveys to establish the presence of wolves. We did not elicit a
howling response at anytime during the evening surveys, although we
did elicit howls when wolves were spotted during daylight hours and
ii
were in close proximity (<300metres) near the two possible den sites.
Future use of howling surveys is not recommended in this type of
mountainous terrain as we conclude that the audible distance of howling
is short 500- 1000 metres, and may not be worth the time and effort
expended.
We assisted in successfully capturing five wolves over the course of the
project resulting in radio collaring of four wolves (including 2 GPS
collars, one placed on an animal in each identified wolf pack). Trapping
proved to be successful when trap sets were established in areas that
wolves frequently used such as the possible den locations or rendezvous
sites identified during this project. Road-based scat and track surveys
and monitoring of trap sets are labor intensive and require a reasonably
large budget primarily in crew-time and vehicle mileage costs to be
completed successfully.
iii
Table of Contents
Acknowledgements................................................................................................ i
Summary .............................................................................................................. ii
Table of Contents................................................................................................. iv
Tables and Illustration.......................................................................................... iv
Introduction ...........................................................................................................1
Methods ................................................................................................................3
Study Area ........................................................................................................3
Presence of Wolves ..........................................................................................4
Capture and Radio-Collaring .............................................................................4
Results..................................................................................................................6
Presence of Wolves ..........................................................................................6
Capture and Radio-Collaring .............................................................................7
Discussion ............................................................................................................8
Presence of Wolves ..........................................................................................8
Capture and radio-Collaring ..............................................................................9
References .........................................................................................................11
Tables and Illustration
Figure 1. Approximate boundary of the study area (red outline) of the North
Thompson wolf inventory project………………………………………………………3
Figure 2. Wolf sign locations and trapping locations for the Serpentine\Albreda
wolf pack………………………………………………………………………………..11
Figure 3. Wolf sign locations and trapping locations for the Berry\Raft wolf
pack……………………………………………………………………………………..12
iv
Introduction
Predation has been identified as the proximate cause of decline in
threatened and endangered populations of the mountain ecotype of
woodland caribou (Rangifer tarandus caribou) in British Columbia
(Wittmer et al. 2005). Investigations of radio-collared caribou mortalities
have implicated several predators including bear (Ursus spp.), wolverine
(Gulo gulo), wolf (Canus lupus) and cougar (Felis concolor) in the deaths of
caribou (Wittmer et al. 2005, R. Serrouya pers.comm.). However recent
attention has focused on wolves due to the likely increase in wolf
populations as a response to greater moose populations (Stotyn et al.
2004). Moose densities have been shown to increase in other areas due
to the increase in early seral habitats created by logging (Serrouya and
D’Eon 2002). While caribou appear to remain spatially separated from
wolves and moose in the late winter, caribou ranges overlap with moose
and wolves in the spring, summer and early winter periods (Bergerud
and Elliot Seip 1992, Stotyn et al. 2005). Increased wolf numbers in the
proximity of caribou are believed to increase the likelihood of wolves
encountering caribou, possibly leading to higher predation rates, during
the seasons when their ranges overlap (Wittmer et al. 2005, Stotyn et al.
2005). The greatest number of radio-collared caribou mortalities have
been shown to occur during the spring and summer seasons, and
caribou are more likely to be preyed upon during these seasons (Wittmer
et al. 2005).
In the North Thompson valley almost no information currently exists on
wolf densities, seasonal movements or annual home ranges. Anecdotal
information exists but is largely contradictory. Evidence from local
trappers suggests wolf density has historically been low and few
instances of wolves trapped on trap lines have been recorded, although
trapping effort is believed to have been low (Kurt Kier, Ministry of
Environment pers. comm.). However, in recent years, several sightings of
wolf packs and wolf kill sites have been reported near the town of Blue
River, BC, with seven wolves seen in one pack one Mud Lake in the
winter of 2004/2005. In addition, anecdotal reports from hunters
suggest wolf packs may be active in several areas throughout the valley,
suggesting wolves maybe more abundant than trapping history would
indicate.
The role of wolves in the decline of caribou sub-populations (Wells Gray
south and Groundhog (Wittmer et al. 2005)) in the North Thompson
valley is suspected but is not well understood. In addition, the presence
of wolves near caribou habitats, particularly in non-winter seasons, such
i
as during the caribou calving season or in the summer season, has not
been established. Thus, the purpose of this project was to improve
information on wolf populations and movements in the North Thompson
Valley. Specifically, the objectives of this project were to:
Conduct an inventory to ascertain the presence\absence of wolves
(Canus lupus) in the North Thompson Valley, particularly in close
proximity to mountain caribou calving and summer habitats.
Where possible, assist Ministry of Environment staff in locating
wolves, setting and monitoring of traps, capture and radio-collaring
wolves.
2
Methods
Study Area
The project study area includes most of the North Thompson Valley and
upper Adams River drainage from north of Vavenby (Road 2) to Clemina
Forest Service Road approximately 25 Km south of Valemount (see
Figure 1). The study area is split between two Ecoregions; The Columbia
Highlands Ecoregion to the south of Blue River characterized by high
elevation plateaus above 1300 metres and the Northern Columbia
Mountains Ecoregion generally north of Blue River characterized by high
mountain peaks and steep, incised valleys (Demarchi, 1996). The study
area generally consists of Interior Cedar Hemlock (ICH) forests mainly in
the valley bottoms below 1300 metres elevation and Engelmann SpruceSubalpine Fir (ESSF) forests above 1300 metres.
Valemount
Wells Gray
Provincial Park
Adams River
North Thomson River
Blue River
Clearwater
Vavenby
Figure 1. Approximate boundary of the study area (red outline) of the North Thompson wolf
inventory project.
3
Presence of Wolves
We used a standardized scat and track survey (Resource Inventory
Standards Committee Inventory methods for Wolf and Cougar, Version
2.0. June 1998) to establish the presence of wolves. For most of the
study area, individual road networks originate along the highway
corridor, thus each road network is considered an individual transect
(RISC, 1998). To determine the presence of wolves along each transect
(road network), we inventoried by 4x4 truck, quad ATV, or by foot along
deactivated roads. We used a vehicle speed of 20 Km/hour or less and
searched each transect twice (once up, once down the road) according to
RISC (1998) standards. We recorded the spatial position (UTM
coordinates) of wolf sightings, scats and tracks in a hand-held GPS. At
each location we recorded the number of scats or tracks and our
estimation of how recent the activity occurred on RISC animal
observation forms (RISC 1998). We removed scats from roads to help
identify new sign of the presence of wolves when re-visiting transects at a
later date. Over the course of the project, we spatially and temporally
spaced our survey effort by surveying most transects several times over
the seven-week period that we conducted the project.
As an additional inventory procedure we used howling surveys to detect
the presence of wolves. We used as similar methodology as Fuller and
Sampson (1988) to elicit howling responses along pre-defined transects
(road systems). On clear, calm evenings we played pre-recorded wolf
howls and vocalizations at pre-determined vantage points along road
systems, starting at the back of the road systems and working our way
out. We chose vantage points that offered a clear, unobstructed view that
we assumed would also allow greater audible projections. Typically
vantage points were 1-2 Km apart to ensure we sufficiently surveyed the
entire length of each transect.
Capture and Radio-Collaring
We assisted an on-going project conducted by Ministry of Environment
staff (John Surgenor and Kurt Kier) to live-trap and radio-collar wolves.
During our scat and track surveys we reported consistent concentrated
wolf activity, usually near kill sites or near trail locations, as possible
trapping locations. Ministry of Environment biologist (Kurt Kier), a
qualified trapper, used steel leg-hold traps to establish trap sets following
RISC (1998) standards and provincial trapping guidelines. Trap sets
consisted of scent posts or trail locations often near kill sites or
rendezvous sites. We checked trap sets twice daily, once in the early
4
morning and once in the evening to ensure an animal was not left too
long in the trap during the warmer summer days. When a wolf was
captured, the animal was immobilized with an injection applied by dartgun. Once the animal was sufficiently sedated, we classified the animal
as to sex, age, estimated weight, recorded standard body measurements
and took hair and blood samples. We fitted captured wolves with either
VHF or GPS radio-collars with a frequency in the 150-151 mHz range.
We remained at the site until the sedative wore off and the animal was
able to move away under its own power.
5
Results
Presence of Wolves
We found the presence of wolves on many transects over the course of
the project. In the first week (July 11-15), our efforts were assisted by the
report of two wolves (one black, one gray) spotted at the bottom of
Serpentine Forest Service Road, and 6 gray wolves in the act of killing a
bull moose at 2 km on road 3022 (spur road at 6 km on Serpentine FSR).
Following this report, we located the kill site and recorded wolf presence
regularly along the Serpentine road system, nearby forestry roads and
power-line access roads over the next several weeks. The highest
concentration of wolf use occurred on the power-line access road as
indicated by a high number of tracks and scats, bones, digging pits and
well used trail networks (see Figure 2). On July 26, while setting traps in
this heavily used area of the power-line, we spotted 9 wolves, including
several pups. Based on this sighting and other reports we estimated the
pack size at 10-12 animals. We recorded wolf sign on several scat and
track transects of nearby roads, however through most of July and
August wolf activity was concentrated along the power-line road and the
lower portions of the Serpentine and Albreda Forest Service Roads
(Figure 2).
On August 2, we sighted several wolves on Berry Creek FSR south of
Blue River (Figure 3). We elicited a howling response at this time
(distance of less than 100 metres) and estimated approximately 10-12
animals present in the area, including several pups. Tracks in the sandy
and muddy sections of the road showed evidence of several wolves, with
prints of various sizes. The immediate area around the sighting was
heavily used with many scats, tracks, well-packed trails and digging
areas. Investigation of the area revealed an older kill site nearby and
evidence of prolonged use of the area as we estimated the kill itself and
many of the scats were 3-4 weeks old. Throughout the next few weeks we
found continued use of this area and nearby roads and trails. The wolves
maintained a significant trail network that provided short cuts to various
parts of the road system. Scat and track transects of nearby road
systems revealed very little to no evidence of wolf presence, again
suggesting wolf use over the span of at least 2 months had been
relatively concentrated in this area (Figure 3).
We recorded a total of 221 separate track or scat locations in the study
area from the period of July 11- September 01, 2005. Of the 221
locations, 117 occurred in Interior Cedar Hemlock (ICH) forest habitats
below 1200 metres elevation. In the more mountainous terrain north of
6
Blue River (Columbia Mountains Ecosection), the majority of scat and
track locations occurred on roads in ICH forests (92 of 102 (90%)
locations) while south of Blue River in the more moderate terrain of the
Quesnel Highlands Ecosection, the opposite occurred as wolf scats and
tracks were most often found above 1300 metres in the ESSF forest
habitats with only 10 of 65 (15.4%) of scat and track locations in ICH
forests. In both cases, the ranges of both wolf packs, based on wolf sign
locations and visual sightings through the two months of the study,
suggest they remain spatially separated from known caribou calving and
summer ranges.
We conducted howling surveys over a period of four weeks from July 11 –
August 05. The howling surveys proved to be much less successful than
the scat and track surveys at establishing the presence of wolves as we
did not elicit a howling response at anytime during the evening surveys.
We elicited a howling response on only three occasions, all of which
occurred when wolves were spotted and in close proximity (less than 300
metres). Two of the responses occurred during daylight hours and all
responses occurred at the two possible den locations.
Capture and Radio-Collaring
We assisted in successfully capturing five wolves over the course of the
project resulting in four radio-collars (including 2 GPS collars, one placed
on an animal in each pack). At the location of the moose-kill on road
3022, a wolf was caught in a trap overnight on July 21st, however, the
animal was able to free itself from the trap before we arrived. On July
28th, a black female sub-adult was captured at the digging locations on
the Serpentine power-line site and fitted with a VHF radio-collar. A week
later, Ministry of Environment staff captured and collared a black adult
male at the same location, again fitting the animal with a VHF radiocollar. On August 21st, another black female was captured, this time at
the Berry Creek kill site and fitted with a GPS radio-collar. On August
30th, a black juvenile male was captured on the Albreda power line
location.
7
Discussion
Presence of Wolves
The scat and track survey method used in this project proved to be
considerably successful at establishing the presence of wolves. Wolves
appeared to regularly use roads, possibly as a means of easy travel or
hunting, thus, when wolves were present in an area, evidence was easily
identifiable by scats deposited on the road and tracks usually found in
mud or soft sand on the road-beds. We found several areas with heavy
use, identified by considerable numbers of tracks, scats, diggings, beaten
down trails into the forest were usually associated with a nearby kill or
rendezvous site (possibly a den site). These sites showed continued use
over several days by more than two animals and animals returned
regularly over the duration of the project. Based on the absence of sign
found on nearby roads over the course of the project, intensive use of
areas, sightings of pups, and howling response from adults and pups
alike, we believe that at this time of year, the wolf packs may be cohesive
and relatively stationary in order to care for pups. In addition we
conclude that two spatially separated, distinct wolf packs of an estimated
10-12 animals each exist in the study area. Our conclusion is based on
the large distance (approximately 55 Km) between the two areas of
concentrated use, where sightings, trapping and howling responses
occurred, and the relative absence of wolf sign between these two areas.
In addition to the two wolf packs found, we recorded several tracks and
scats on road systems far away from the high use areas, however these
were most often associated with solitary animals, and we are uncertain if
these belong to the two packs identified or another group.
The locations of scats and tracks suggest that the two distinct wolf packs
use different habitats in the summer months. The northern pack
(Serpentine\Albreda) used mainly lower elevations while the southern
pack (Berry\Raft) used many high elevation habitats. Differences in
elevation are likely the result of the availability of prey (moose) associated
with early seral habitats. The high elevation plateaus to the south of Blue
River have extensive road networks and large cutblocks that provide good
habitat conditions for moose above 1300 metres while in the steeper
valleys north of Blue River, road networks and the greatest density of
cutblocks (early seral habitats) occur at lower elevation near the valley
bottoms. The differences in elevations where logging has historically
taken place, between the two areas where the wolf packs were located,
likely result in greater densities of moose at higher elevations south of
Blue River, and in the valley bottoms to the north. Previous studies have
shown that wolves generally follow moose seasonal movements of moose,
8
primarily in the summer months when moose are the main food source
(Seip 1992, Stotyn et al. 2005). Based on this, we hypothesize that
differences in elevations that wolf sign was found between the southern
and northern wolf packs is linked to greater moose densities associated
with the availability of early seral habitats.
Our results suggest that for most of the summer period (July-August),
wolves use lower elevation habitats and are spatially separated from
known mountain caribou calving and summer habitats. The distribution
of wolves at lower elevations (<1300 metres) and caribou use of high
elevations (> 1500 –1700 metres) in the North Thompson during the
summer period is consistent with results from radio and GPS- collared
wolves studied in those areas (Stotyn et al 2005, Seip 1990). However,
because we did not inventory the high elevation parkland and alpine
habitats, we cannot be sure that wolves were not present in these areas
over this time period.
The howling survey proved to be a less successful method to establish
the presence of wolves. Our original impression was that howling should
have carried over a large distance in the deeply incised valleys where
most of the survey was conducted. However, the noise of many streams
and the larger rivers at the base of the valley likely shrouded our howling
vocalizations and recorded playbacks, especially in early July when most
watercourses in the area flow heavily. We tested the audible range of our
howls on only a few occasions, and judging by the combination of terrain
and stream noise, our opinion is that the audible range was typically 500
metres or less. In our opinion, the scat and track surveys on road
systems is a better approach to locating wolves.
Capture and radio-Collaring
Trapping and collaring of wolves during the summer also proved to be
relatively successful. In most cases, if recent presence of wolves in an
area was confirmed, a wolf was captured or visited the trap locations
within the first two nights after the trap was set. We captured five wolves
in a period of 5 weeks and on at least two occasions wolves visited the
traps, often stepping within inches of the release plate but without
triggering the trap. Both the scat and track surveys and monitoring of
leg-hold traps are labor intensive and require a reasonably large budget
primarily in crew-time and vehicle mileage costs. However, this method
proved to be successful in trapping wolves during the summer months.
9
Conclusions
Inventory Methods
The RISC scats and track survey method used in this project proved
to be considerably successful at establishing the presence of wolves.
Further use of this inventory method is recommended.
Live –trapping of wolves using leg-hold traps proved to be successful
in the summer months because we were able to maintain consistent
knowledge of the location of wolf packs once they were located due to,
we believe, the packs being less mobile during this period while caring
for pups.
The howling survey proved to be a less successful method to establish
the presence of wolves. In our opinion, the scat and track surveys on
road systems is a better approach to locating wolves.
Both the scat and track surveys and monitoring of leg-hold traps are
labor intensive and require a reasonably large budget primarily in
crew-time and vehicle mileage costs.
Wolf Distribution and Movements
Based on the absence of sign found on nearby roads over the course
of the project, intensive use of areas, sightings of pups, and howling
response from adults and pups alike, we believe that at this time of
year, the wolf packs may be cohesive and relatively stationary in order
to care for pups.
We conclude that two spatially separated, distinct wolf packs of an
estimated 10-12 animals each exist in the study area. The locations of
scats and tracks suggest that these wolf packs use different habitats
in the summer months likely associated with the availability of prey.
The distribution of wolves during the summer, based on wolf sign
locations and visual sightings through the two months of the study,
suggest they remain spatially separated from known caribou calving
and summer ranges.
10
References
Bergerud, A.T. and J.P. Elliott. 1986. Wolf predation in a multiple ungulate
system in northern British Columbia. Can J. Zool. 76: 1551-1569.
Demarchi, D.A. 1996. An Introduction to the Ecoregions of British Columbia:
Victoria, British Columbia, Canada. B.C. Ministry of Environment, Lands
and Parks.
Fuller, T.K. and B.A. Sampson. 1988. Evaluation of a Simulated Howling
Survey for Wolves. J. Wildl. Manage. 52(1): 60-63.
RISC 1998. Resources Inventory Standards Committee. Inventory Methods for
Wolf and Cougar: Standards for Components of British Columbia’s
Biodiversity No. 34. Version 2.0. June 1998
Seip 1992. D.R., 1992. Factors limiting woodland caribou populations and their
interrelationships with wolves and moose in southeastern British
Columbia. Can. J. Zool. 70: 1494-1503.
Serrouya, R., and R, D’Eon. 2002. Moose habitat selection in relation to forest
harvesting in deep snow zone of British Columbia. Prepared for Downie
Timber Ltd., Revelstoke, British Columbia.
Stotyn, S, R. Serrouya, and B. McLellan. 2005. The predator-prey dynamics of
wolves and moose in the northern Columbia Mountains: spatial and
functional patterns in relation to mountain caribou decline. Unpublished
report prepared for British Columbia Forest Science Program, Downie
Street Sawmills Ltd, Parks Canada and the Columbia Basin Fish and
Wildlife Program. 22 pp.
Wittmer, H.U., B.N. McLellan, D.R. Seip, J.A. Young, T.A. Kinley, G.S. Watts,
and D. Hamilton. 2005.Population dynamics of the endangered mountain
ecotype of woodland caribou (Rangifer tarandus caribou) in British
Columbia, Canada. Can. J. Zool. 83: 407-418.
11
Figure 2. Wolf Sign Locations, trapping locations for the Serpentine\Albreda wolf pack
N
Location of wolf captured
and GPS radio-collared on
Albreda power-line access.
N. Thompson FSR
Lempr
iere
FSR
Serpentine Power-line
Access Road
Existing and
planned cutblocks
Trap sets
Serpentine FSR
Road 3022
Location of rendezvous
site on Serpentine powerline road where wolves
observed, howling
response elicited and two
wolves captured and
radio-collared.
2 Km Road 3022, where
wolves seen killing
moose July 12, wolf
captured but freed itself
from trap
Scat and Track
Locations
12
Figure 3. Wolf Sign Locations, trapping locations for the Berry\Raft wolf pack
die
Ped
FSR
N
Location of kill site where
wolves observed, howling
response elicited and wolf
captured and GPS radiocollared.
Wells Gray
Provincial Park
FSR
Berry
Park FSR
Scat and Track
Locations
Finn FSR
Raf
t
Trap sets
FSR
Foam FSR
Avola Mtn FSR
13