Author(s): James A. Schaefer, A. M. Veitch, F.H. Harrington, W.K. Brown, J.B. Theberge, S.N. Luttich
Date: 01-Dec-00
Source: Oecologia (2001) 126:507–514
Number on Library Shelf: 11

http://www.trentu.ca/~jschaefe/Schaefer2001Oecologia.pdf

Examining both spatial and temporal variation can provide insights into population limiting factors. We investigated the relative spatial and temporal changes in range use and mortality within the Red Wine Mountains caribou herd, a population that declined by approximately 75% from the 1980s to the 1990s. To extract the spatial structure of the population, we applied fuzzy cluster analysis, a method which assigns graded group membership, to space use of radio-tracked adult females, and compared these results to a hard classification based on sums-of-squares agglomerative clustering. Both approaches revealed four subpopulations. Based on the subpopulation assignments, we apportioned the number of animals, radio-days, calving events and mortalities across subpopulations before and after the decline. The results indicated that, as the herd declined, subpopulations were disproportionately affected. In general, subpopulations with the greatest range overlap with migratory caribou from the George River herd experienced comparative reductions in activity and increased mortality. The subpopulation with the least overlap exhibited the converse pattern. The infra-population imbalances were more pronounced when herd clustering was employed. Our results reiterate that refugia from other ungulates may be important in the persistence of taiga-dwelling caribou. We propose that changes across time and space are valuable assays of localized demographic change, especially where individuals exhibit spatial hyperdispersion and site fidelity.
 

Author(s): Wayne L. Wakkinen
Date: 19-Jun-95
Source: Journal of Applied Ecology
Volume 37 Issue 4 Page 589 - August 2000
Number on Library Shelf: 44

We attempted to develop a model to quantify factors affecting visibility of woodland caribou and provide statistically valid population estimates. Our design consisted of a 2-stage sampling effort: a "pre-census" fixed wing flight to determine caribou distribution and a "census" flight using a helicopter to count and classify individuals. Radio-marked caribou were used to quantify conditions of non-detection. We detected 100% of the groups with at least 1 radio-marked caribou during the fixed-wing flights (n=27). Eighty-three percent (23 of 27) of these groups were detected during the helicopter census. The conditional probability of detecting a group during the census was ) 0.81 at the 90% confidence level. The minimum population size was determined to be 47, 47, 51 and 45 in 1991-1994. Modeling the detection factors had limited value for the highly successful technique described here. The 2-stage method has applications in wildlife census work where animals are unpredictably grouped within a large geographic area.
 

Mountain  Caribou Censuses in the North Columbia Mountains

Author(s): Bruce McLellan, John Flaa, John Woods
Date: 25-Mar-03
Source: 759-766 in L.M. Darling, ed. 2000. Proc. Conf. on the Biology and Manage. Species and Habitats at Risk, Kamloops, B.C., 15-19 Feb., 1999. Vol. 2; B.C. Minist. Environ., Lands and Parks, Victoria, BC, and Univ. College of the Cariboo, Kamloops, BC. 520pp
Number on Library Shelf: 68

http://www.cbfishwildlife.org/reports/teaser.php?report_id=56

Woodland caribou (Rangifer tarandus caribou) in southeastern British Columbia feed on arboreal lichen during the winter that are most abundant on old trees and thus have been identified as an old-growth dependent species (B.C. Ministry of Environment 1989). Clear-cut harvesting of mature forests has been perceived as being incompatible with maintaining winter habitat for caribou. The relationship between the amount of clearcutting plus other forms of human intrusion into caribou habitat and actual numbers of caribou is unknown. To develop an understanding of this relationship, the number of caribou must be known and we must have the ability to track their numbers as the condition of their habitat changes. The primary purpose of this report is to present information on a caribou census conducted in March 1994. It is hoped that this census can be used as a benchmark for future censuses. In addition, we summarized caribou censuses conducted in this area in 1993, and others conducted in the past by the B.C. Hydro Mica and Revelstoke Compensation Programs (MCRP) and by Ministry of Environment, Lands and Parks (MOELP).
 

Author(s): Bruce McLellan, Janis Hooge, John Flaa
Date: 30-Apr-02
Source:
Number on Library Shelf: 80

This document reports on a study conducted in the Columbia Forest District in which mountain caribou were radiocollared in attempts to identify and monitor the population. 
 

Author(s): David J. Freddy, Albert W. Erikson
Date: 01-Aug-72
Source:
Number on Library Shelf: 101

http://www.cmiae.org/compendium/reference101.pdf
5.2 MB (scanned)

The Selkirk Mountain caribou (Rangifer tarandus montanus) are the only naturally remaining caribou in the contiguous United States, being found in the Selkirk Mountains on northern Idaho, northeastern Washington and southern British Columbia, Canada. Observations indicate there is a minimum of 35 caribou in the herd. These animals are divided into at least three small groups and occupy a somewhat discontinuous range. The animals wintered in the subalpine fir-Engelmann spruce forest in areas of moderate relief between the elevations of 1,380 m and 2,160 m. Arboreal lichens of the genus Alectoria range comprised the main winter food. Ecological damage to already limited winter range could seriously jeopardize the size and distribution of this herd. Special land classification, logging restrictions, forest fire control and continued protected status for these animals are essential management considerations.
 

Caribou and Moose Habitat Inventory and Habitat Management Guidelines in the Columbia River Drainage near Revelstoke B.C.

Author(s): Keith Simpson, John P. Kelsall, Chris Clement
Date: 01-Aug-88
Source:
Number on Library Shelf: 102

The report deals with moose and caribou and their habitat in timber supply areas near Revelstoke, B.C. As a result of wildlife studies near Revelstoke and accelerating development in the area, the Ministry of Environment and Parks identified a need to inventory critical habitats for moose and caribou and to develop management guidelines, which will ensure the maintenance of wildlife populations in the area.
 

Development of a preliminary habitat assessment and planning tool for mountain caribou in southeast British Columbia

Author(s): Clayton D. Apps, Trevor Kinley
Date: 01-Jan-98
Source: Prepared for FRBC, Report #MR270
Number on Library Shelf: 106

http://www.for.gov.bc.ca/hfd/library/frbc1997/FRBC1997MR270.pdf

The Purcell Mountains of southeast British Columbia support a population of mountain caribou near the southernmost extension of their range. This ecotype is dependent upon late-successional forests, largely because such stands provide arboreal lichen for winter forage. Recent provincial forest practices legislation and land-use planning initiatives have provided the impetus for developing an interim caribou habitat assessment model for use as a planning tool. We applied the HIS (habitat suitability index) model developed for a nearby population as a testable hypothesis of caribou habitat selection in the southern Purcells. In a study area of about 6000km2, 512 radiolocations were obtained for 22 animals from 1993 through 1995. Seasonal selectivity was assessed for the following model variables: elevation, slope, habitat type/current cover type, over story size class, canopy closure, and age of dominant over story. Caribou were most selective for stand age, which the model also defined as the greatest determinant of habitat suitability. However, we did not judge overall model output to be an adequate predictor of habitat selection by southern Purcell caribou. Seasonal ratings for each variable were therefore modified to better reflect selection patterns by animals in this study, and subjectively adjusted to ensure that potentially limiting habitat types were rated highly. An evaluation of the adjusted model established its efficacy as an interim decision-support tool. Selection analyses of spatial habitat distribution levels indicated a preference by caribou for landscapes with at least 40% suitable habitat per 250 ha and per 5000 ha. From this, it is apparent that suitable habitat is highly fragmented in this study area.
 

Caribou in British Columbia: A 1996 status report

Author(s): Douglas C. Heard, Kathryn L. Vagt
Date: 01-Jan-98
Source: Rangifer, special issue #10: 117-123
Number on Library Shelf: 107

Caribou (Rangifer tarandus) in British Columbia are classified into mountain, northern and boreal ecotypes based on behavioural and ecological characteristics. We recognized 12 mountain caribou herds, 27 northern caribou herds, and an area occupied by low density boreal caribou dispersed in the boreal forests of the northeast portion of the province. Abundance estimates were usually based on attempts at total counts made from the air. Trends were based on repeated population estimates or the difference between recruitment and mortality rates for each herd. In 1996 there were approximately 18 000 caribou in British Columbia; 2300 mountain and 15 600 northern and boreal. These estimates suggest a slight increase in the numbers of both ecotypes over the last 18 years. Fifteen percent of the herds were reportedly increasing, 10% were decreasing, 31% were stable, but for 44% of the herds the trend was unknown. Historically caribou were found throughout 8 of the 14 biogeoclimatic zones in B.C. Caribou are now rarely found in the Sub-Boreal Spruce zone, likely due to an increase in predation from wolves that increased in response to increasing moose numbers. Ranges of several herds in the Englemann Spruce-Subalpine Fir and Alpine Tundra zones of south-eastern British Columbia are also reduced relative to historic conditions, probably because of habitat loss, habitat fragmentation, predation and hunting. Forest harvesting represents the greatest threat to caribou habitat and current research focuses on the mitigation of forest harvesting impacts.
 

Mountain Caribou Habitat Use and Population Characteristics for the Central Selkirks Caribou Inventory Project

Author(s): Dennis Hamilton, Steven F. Wilson, Graham Smith
Date: 31-Mar-00
Source:
Number on Library Shelf: 112

This project was designed to provide the population and habitat inventory data necessary to effectively integrate the needs of mountain caribou with forest landscape planning and operational management.
 

Caribou Research and Management in British Columbia

Author(s): BC Ministry of Forests, BC Ministry of Environment
Date: 07-Nov-85
Source: Proceedings of a workshop. BC Ministry of Forests, Research Branch, WHR-27, Victoria, BC
Number on Library Shelf: 113

Proceedings of a workshop in Kamloops, 1985.
 

Caribou censuses in the Kinbasket Lake and Duncan River areas

Author(s): John Flaa
Date: 17-Jun-95
Source: Study done for Columbia Basin Fish and Wildlife Compensation Program.
Number on Library Shelf: 119

To order a copy: http://www.cbfishwildlife.org/reports/teaser.php? report_id=57

This report outlines the results of caribou censuses for the Kinbasket Lake area, completed in 1995.
 

Robson Valley Caribou Population Review

Author(s): Eliot Terry
Date: 01-May-95
Source: Ministry of Environment, Lands and Parks, Prince George
Number on Library Shelf: 122

The purpose of this report is to compile available information on woodland caribou in the Robson Valley and provide a review of population distribution, seasonal movements and monitoring needs.
 

Updated COSEWIC Status Report on "Forest-Dwelling" Woodland Caribou

Author(s): Donald C. Thomas, David R. Gray
Date: 01-Aug-01
Source: Prepared for the Committee on the Status of Endangered
Wildlife in Canada (COSEWIC), 2002.
Number on Library Shelf: 124

This document is an in-depth summary on the status of woodland caribou.
 

Selkirk Mountains Woodland Caribou Herd Augmentation in Washington

Author(s): Audet, Suzanne; Allen, Harriet
Date: January 1996
Source:
Number on Library Shelf: 126

http://wdfw.wa.gov/wlm/research/caribou/caribpub.htm

The Selkirk Mountain woodland caribou (Rangifer tarandus caribou) is listed by the U.S. Fish and Wildlife Service as an endangered species in the United States. It is also designated as an endangered species in Washington by the Washington Department of Fish and Wildlife. The recovery plan for the caribou (USFWS, original 1985; revised 1994) includes a task to establish caribou in the western portion of the Selkirk Ecosystem in Washington. Transplants to the western portion of the ecosystem are needed to achieve better distribution, greater abundance, and to enhance the probability of caribou recovery.

The augmentation project entails capturing caribou in separate, but genetically similar subpopulations in British Columbia, transporting the animals to Washington, releasing them into the wild, and monitoring the results. Previous herd augmentation efforts for the southern Selkirk caribou population involved transplanting caribou from healthy populations in British Columbia to the Ball Creek area of Idaho. A total of 60 caribou were transplanted: 24 in 1987; 24 in 1988; and 12 in 1990. Information and experience gained in the Idaho effort will be used to increase the chances for success of the Washington project.

Three potential sources for transplant animals in British Columbia will be considered: Revelstoke, Blue River/Wells Gray Park, and Prince George. British Columbia officials will determine the number and sources of transplant animals. The target number of animals for the first year will be 20-24 animals, with a sex ratio of 1 male: 4-5 females. Preferred age composition is males 3 years or younger, calves, yearlings, and adult females. Old-aged females or animals in poor condition will be excluded. Methods will follow those used in the Idaho augmentation effort, which experienced very low mortality rates. Animals will be captured in March, using net guns from helicopters. They will be held for tuberculosis and brucellosis testing and then transported to the release site in Washington.

Four potential release sites on the Sullivan Lake Ranger District of the Colville National Forest were evaluated. One site, Molybdenite Ridge was eliminated from consideration. Potential release sites, in order of preference are: Pass Creek, Mankato Mountain, and upper Sullivan Creek. All are within the Caribou Habitat Area, are currently managed as caribou habitat under the Colville National Forest Plan (U.S. Forest Service 1988), and will require no change in management to accommodate the augmentation effort. The final site selection will depend upon weather conditions and road access at the time of release.

Preliminary work (administrative, habitat mapping, caribou feeding trials) has been conducted during 1995 to facilitate the augmentation project. Pending funding approval, the first transplant will take place in March 1996. Caribou recovery is an interagency and international effort requiring public support and involvement. Law enforcement needs are identified in the augmentation plan and will emphasize prevention of accidental or intentional shooting. Information/Education needs are also addressed in the plan. Some of the information/ education efforts used during the Idaho augmentation effort, such as the "Adopt a Caribou" program, will be used in the Washington project.
 

Moose Population Monitoring in the Lake Revelstoke valley. 2002-2003

Author(s): Poole, K, and Serrouya, R.
Date: March 2003
Source:
Number on Library Shelf: 127

Moose (Alces alces andersoni) numbers north of Revelstoke in the northern Columbia Mountains of British Columbia appear to have increased substantially over the past 2 decades. This has led to mounting conflicts with forestry interests, and concern has been raised about the impact of a moose supported and apparently increasing wolf (Canis lupus) population on a sympatric and declining mountain caribou (Rangifer tarandus caribou) herd. To provide a current estimate of moose numbers in this area and strengthen background data for management decisions, we conducted a stratified random block aerial survey 14–28 January 2003. The primary objectives were to estimate moose density (absolute abundance) and composition within the study area. A secondary objective was to estimate moose numbers and distribution along the Illecillewaet and Tangier rivers northeast of Revelstoke. Finally, we wanted to present methods to monitor relative abundance, and discuss using aerial methods versus a pilot study based on pellet transects.

Comparisons with previous survey data suggest that moose numbers in the study area have more than doubled in the past 9–12 years. Given current harvest rates, hunter harvest likely could be more than doubled while still maintaining a stable population. Given the importance of Lake Revelstoke moose numbers in the context of wolf/caribou dynamics and forestry concerns, we recommend annual moose population monitoring. We suggest that a stratified random block survey be conducted every 5 years, with annual trend monitoring conducted by either pellet-group transects or aerial surveys of a sample of sample units in high and medium density areas. The former method may be less costly with the use of local volunteers, but will not provide data on age and sex ratios.
 

Population Status and Mortality of Mountain Caribou in the Southern Purcell Mountains, British Columbia.

Author(s): Trevor Kinley and Clayton Apps
Date: February 1999
Source: Pp. 655-661 in L.M. Darling, ed. 2000. Proc. Conf. on the Biology and Manage. Species and Habitats at Risk, Kamloops, B.C., 15-19 Feb., 1999. Vol. 2; B.C. Minist. Environ., Lands and Parks, Victoria, BC, and Univ. College of the Cariboo, Kamloops, BC. 520pp.
Number on Library Shelf: 134

http://wlapwww.gov.bc.ca/wld/documents/mc07kinley.pdf

Population surveys and mortality monitoring for mountain caribou, an ecotype of woodland caribou (Rangifer tarandus caribou), were conducted in the southern Purcell Mountains of British Columbia from 1994 to 1998. Results indicated that this subpopulation was declining, with annual growth rates ranging from 0.82 to 0.88. This was a result of low calf recruitment (late-winter ratios of 0.00–0.13 calves per adult) and high adult mortality (mean annual rate = 0.27). Reasons for low recruitment were unknown, but most adult mortality was attributed to predation, particularly by cougars (Felis concolor). The difference in mortality rate between sexes was non-significant (P = 0.14), but was consistent with increasing bull: cow ratios observed during the study. The southern portion of the study area had more recent cutblocks and fires (i.e., forests <40 years), greater road density, and more fragmentation than the northern portion. Caribou mortality was also significantly greater in the south than the north (P = 0.03). This mortality may have been partly due to post-logging changes in the distribution of ungulates favouring edges and early-seral forests, and the predators that were attracted to these ungulates. If current trends continue, the southern Purcell caribou herd will be extirpated within a decade. To address this problem, we recommend that (1) this subpopulation be augmented with animals from other mountain caribou herds; (2) relationships between predation and patterns of forest harvesting be investigated, with harvesting either deferred in some areas or designed to minimize enhancement of other ungulates’ forage; and (3) limiting predation on caribou by reducing the number of cougars and alternate prey be investigated.
 

Population Characteristics of the Lake Revelstoke Caribou

Author(s): John Flaa and Bruce McLellan
Date: February 1999
Source: Pp. 639-642 in L.M. Darling, ed. 2000. Proc. Conf. on the Biology and Manage. Species and Habitats at Risk, Kamloops, B.C., 15-19 Feb., 1999. Vol. 2; B.C. Minist. Environ., Lands and Parks, Victoria, BC, and Univ. College of the Cariboo, Kamloops, BC. 520pp
Number on Library Shelf: 136

http://wlapwww.gov.bc.ca/wld/documents/mc03flaa.pdf

The Lake Revelstoke caribou are the southernmost contiguous mountain caribou population in British Columbia. Population characteristics of the herd were examined during 1981–85, with 13 radio-collared caribou, and1992–98, with 47 radio-collared caribou. During several late-winter censuses, sightability of marked animals was 92% and the proportion seen was a function of the height of snow. Our best estimate of the population size was 375animals (95% CI 337–413). Cause of death of 31 radio-collared animals included accidents (42%), predation (29%),and poor condition (10%). Deaths due to avalanches (accidents) were the single leading cause at 23%. Survival of radio-collared caribou averaged 84% since 1992. Progesterone levels in 29 female caribou indicated that 83% were pregnant. There was an average of 28 calves/100 adults during 1981–84, and 18 calves/100 adults during 1994–97.Survival rates of adult caribou and the ratio of calves per 100 adults indicate that the population was stable.
 

Mountain Caribou Habitat Use in the Salmon Arm Forest District:
2000-2002, Preliminary Report #1

Author(s): Kelsey Furk, Bruce McLellan
Date: March 2003
Source: Produced under contract to:
Okanagan Innovative Forestry Society, 4280 Highway 6, Lumby, BC V0E 2G7
gadick@riverside.bc.ca
Number on Library Shelf: 140

www.cmiae.org/compendium/reference140.doc

The Okanagan Shuswap Land and Resource Management (OSLRMP) area contains part of three caribou populations identified by Simpson et. al (1997). These are the Wells Gray South, Revelstoke and Monashee populations. In 2001 (OSLRMP) established a Caribou Resource Management Zone (RMZ) with associated connectivity corridors in the Okanagan TSA. The OSLRMP specifies management guidelines for Caribou in this RMZ.

The Okanagan Innovative Forestry Society (OIFS) contracted a caribou study in response to the OSLRMP call for further caribou habitat information. This report documents progress of the study over the first two years of a seven-year project. The OIFS Forestry Plan (2001) identifies five main objectives for this project:

• Identifying opportunities to supply suitable caribou habitat attributes through forest management activities.
• Investigating caribou populations, including predation and mortality; and
• Link monitoring from this project to ongoing caribou research projects in the Columbia and Clearwater Forest Districts.
• Identifying the caribou habitat requirements in the ICH and ESSF zones;
• Examining the relationship between forest management activities and relative caribou habitat use in the ICH and ESSF zones.

Caribou research projects in the Columbia and Clearwater Forest districts have also identified caribou movements in the Salmon Arm Forest District. Data from all three studies will be combined to complete the objectives of this study.
 

Caribou Site Seasonal Home Ranges in the North Thompson Watershed of British Columbia 1996-98

Author(s): Garth Mowat and Kim Poole
Date: March 1999
Source: Ministry of Environment Lands and Parks Kamloops BC
Number on Library Shelf: 147

www.cmiae.org/compendium/reference147.doc

Caribou range size followed predictable patterns. Home range sizes were relatively restricted in summer and late winter while caribou moved much further in early winter and spring. Caribou seek out patchy resources during these 2 later periods and this searching appears to effect home range size. During early winter caribou seek wind fallen trees and branches, and during spring caribou seek out early green-up areas which are patchily distributed through the landscape and of limited size (and therefore quickly exploited). These analyses show clearly that the calving strategy of this group of caribou is to move to a higher elevation area (Mowat et al. 1998) before parturition and remain there for 3-4 weeks before resuming significant movements. Figure 5 shows several potential calving areas, 2 of which were used by 2 different caribou (upper Lempriere creek and upper Mrytle creek) These results are similar to those of Mowat et al. (1998) except that the early spring movements were smaller in 1996 and 1997 than during 1998. Summer home ranges were also somewhat smaller in this study but this was largely caused by caribou 36 which had a summer home range of only 3 km2 in 1998. Perhaps this animal was dead or lost its collar. Mowat et al. (1998) suggested that season cut-off dates be selected by examining the behaviour of individuals; this is likely to result in a more accurate picture of seasonal movements.
 

Robson Valley Caribou Surveys

Author(s): March 2001
Date: Dale Seip
Source: Robson Valley Forest District, Enhanced Forestry Management Pilot Project
Number on Library Shelf: 150

http://www.firthhollin.com/efmpp/research/caribou2001.pdf

Prior to the start of this project in March 2000, there had not been a complete population survey of caribou in the Robson Valley so it was unclear how many caribou lived there. The habitat management zones were based on historic observations, habitat characteristics, and a limited amount of telemetry data. It was not clear if those areas were currently being used by caribou in winter. Additional information on winter distribution was required to more clearly define important winter habitat areas. The purpose of this project is to conduct winter surveys of mountain caribou distribution in the Robson Valley to determine how many caribou there are.
 

COSEWIC Assessment and Update Status Report on the Woodland Caribou

Author(s): D.C. Thomas and D.R. Gray
Date: 2002
Source: Committee on the Status of Endangered Wildlife in Canada, Ottawa
Number on Library Shelf: 152

http://www.sararegistry.gc.ca/virtual_sara/files/cosewic/sr_woodland_caribou_e.pdf 

Woodland caribou (Rangifer tarandus caribou) are medium-sized (100-250 kg) members of the deer family. The taxonomy (classification) and systematics (evolutionary history) of caribou in Canada are uncertain. Based on mitochondrial DNA, caribou in North America evolved from two founding groups (clades) that differentiated in isolation during the last (Wisconsinan) glaciation. The southern clade supposedly evolved south of the continental ice sheet, whereas the northern clade was in a glacial refugium in Alaska and adjacent Arctic Canada. Populations that contained unique southern gene types were the Pukaskwa local population in Ontario and two in Newfoundland. In contrast, exclusively northern types occurred in four Yukon populations and in some forest-tundra and tundra ecotypes of barren-ground caribou (R. t. groenlandicus) in northern Canada. Most woodland caribou populations in the mountains of southern British Columbia (B.C.) and Alberta and in the boreal forest and taiga across Canada are mixtures of the two types. Some 'mixed' populations in the taiga exhibit two phenotypes and behave like the forest-tundra ecotype of barren-ground caribou.
 

2004 Population census of mountain caribou in the Columbia Forest District

Author(s): Janis Hooge, Bruce McLellan, John Flaa
Date: 2004
Source:
Number on Library Shelf: 155

www.cmiae.org/compendium/reference155.pdf

Mountain caribou in the Columbia Forest District were studied using radio telemetry from 1992 to 1999. Censuses conducted in 1994, 1995, 1996, and 1997 indicated a relatively stable population of between 290 to 373 animals. In 2002, census efforts were coordinated throughout the range of mountain caribou in British Columbia and resulted in a population estimate of 211 animals for the Revelstoke area, or a decline to 64% of the 1997 estimate. A downward trend occurred in most mountain caribou subpopulations in southern B.C. However, because there were only 5 radio collared animals remaining in the Revelstoke area in 2002, the sightability of the population (proportion of the total population actually observed) could not be well estimated, resulting in a wide confidence interval of 176-269 animals. The decline was confirmed during the 2004 census, with a population estimate of 176. The 90% confidence interval for the 2004 census was 167-210 animals, based on sighting 14 of the 15 radiocollars available.
 

2004 Population Census for the Central Selkirk Mountain Caribou

Author(s): Dennis Hamilton
Date: April 10, 2004
Source: Prepared for Pope & Talbot Ltd. Slocan Forest Products, Meadow Creek Cedar Company, Canadian Mountain Holidays
Number on Library Shelf: 166

www.cmiae.org/compendium/reference166.pdf

Central Selkirk mountain caribou population estimates have declined in every census year since surveys began in 1996. The 1996 census flight observed 211 animals where 12 of 14 radio-collared caribou were spotted. The 2002 census, in which 96 caribou were spotted and 6 of 9 radio-collared animals were sighted, resulted in a population estimate of 131 caribou in the study area. The 2002 result was the first year in which a population trend could be established statistically.

A total of 70 animals, including 13 calves, were spotted during helicopter census flights completed in March 2004. Following the census flights, a supplemental fixed wing survey of the peripheral of the study area was conducted, but no caribou were observed. There was only one radio-collar still active in the study area at the time of the 2004 census; consequently, no measure of sightability (ratio of marked animals seen to known number of marked animals) was calculated. A total count for all census years and population estimates in years where mark-resight data were available are presented.

Due to recent population trend, it is recommended that a population census be conducted every year for the next few years. As mountain caribou are relatively easy to census, weather and climatic conditions permitting, no additional caribou collaring is needed at this time.

Forestry, backcountry recreation and mountain caribou recovery require a coordinated effort if current population trend for the Central Selkirk mountain caribou is to be reversed.
 

Population dynamics of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada

Authors: Heiko Wittmer, Bruce McLellan, Dale Seip, James Young, Trevor Kinley, Glen Watts, Dennis Hamilton
Date: 2005
Source: Canadian Journal of Zoology 83: 407-418
Number on library shelf: 174

http://article.pubs.nrc-cnrc.gc.ca/ppv/RPViewDoc?_handler_=HandleInitialGet&journal=cjz&volume=83&calyLang=eng&articleFile=z05-034.pdf

Abstract: We used census results and radiotelemetry locations of >380 collared individuals sampled over the entire distribution of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) in British Columbia, Canada, to delineate population structure and document the size and trend of the identified populations. We also describe the spatial pattern of decline and the causes and timing of adult mortality and provide estimates of vital rates necessary to develop a population viability analysis. Our results indicate that the abundance of mountain caribou in British Columbia is declining. We found adult female annual survival rates below annual survival rates commonly reported for large ungulates. The major proximate cause of population decline appears to be predation on adult caribou. Spatial patterns of population dynamics revealed a continuous range contraction and an increasing fragmentation of mountain caribou into smaller, isolated subpopulations. The population fragmentation process predominantly occurs at the outer boundaries of the current distribution. Our results indicate that recovery strategies for mountain caribou should be directed at factors contributing to the fragmentation and isolation of mountain caribou populations as well as management strategies aimed at increasing adult survival.

Comment arising from a paper by Wittmer et al.: Hypothesis testing for top-down and bottom-up effects in woodland caribou population dynamics.

Authors: Glen S. Brown, Lynn Landriault, Darren J.H. Sleep, Frank F. Mallory
Date: August 2007
Source: Oecologia DOI 10.1007/s00442-007-0855-3
Number on library shelf: 181

http://www.cmiae.org/compendium/reference181.pdf

Conservation strategies for populations of woodland caribou Rangifer tarandus caribou frequently emphasize the importance of predator–prey relationships and the availability of lichen-rich late seral forests, yet the importance of summer diet and forage availability to woodland caribou survival is poorly understood. In a recent article, Wittmer et al. (Can J Zool 83:407–418, 2005b) concluded that woodland caribou in British Columbia were declining as a consequence of increased predation that was facilitated by habitat alteration. Their conclusion is consistent with the findings of other authors who have suggested that predation is the most important proximal factor limiting woodland caribou populations (Bergerud and Elliot in Can J Zool 64:1515–1529, 1986; Edmonds in Can J Zool 66:817–826, 1988; Rettie and Messier in Can J Zool 76:251–259, 1998; Hayes et al. in Wildl Monogr 152:1–35, 2003). Wittmer et al. (Can J Zool 83:407–418, 2005b) presented three alternative, contrasting hypotheses for caribou decline that differed in terms of predicted differences in instantaneous rates of increase, pregnancy rates, causes of mortality, and seasonal vulnerability to mortality (Table 1, p 258). These authors rejected the hypotheses that food or an interaction between food and predation was responsible for observed declines in caribou populations; however, the use of pregnancy rate, mortality season, and cause of mortality to contrast the alternative hypotheses is problematic. We argue here that the data employed in their study were insufficient to properly evaluate a predation-sensitive foraging hypothesis for caribou decline. Empirical data on seasonal forage availability and quality and plane of nutrition of caribou would be required to test the competing hypotheses. We suggest that methodological limitations in studies of woodland caribou population dynamics prohibit proper evaluation of the mechanism of caribou population declines and fail to elucidate potential interactions between top-down and bottom-up effects on populations.
 

2005 Population Census of Mountain Caribou in the Central Selkirk Mountains of Southeastern British Columbia

Authors: Dennis Hamilton, Steve Wilson
Date: April 18. 2005
Source: Prepared for Canadian Forest Products, Pope and Talbot Ltd. Canadian Mountain Holidays, Mount Revelstoke and Glacier National Parks.
Number on Library Shelf: 169

www.cmiae.org/compendium/reference169.pdf

This census is part of the ongoing monitoring of the Central Selkirk subpopulation.