Assessing the Design and Functionality of Wildlife Movement Corridors in the Southern Canmore Region - cont'd.
The Bow Valley is a living treasure chest. Here, wolves denning on the sunny south slopes of the Fairholme Range; there, elk and deer in golden stands of shimmering aspens; and, over there, a lynx patiently waiting for snowshoe hare beneath snow-draped mountain slopes. And above, the wondrous migration of golden eagles over Mt. Lady MacDonald. The Bow Valley also has treasures of another type. Dedicated and concerned individuals who are willing to work hard for the integrity of this valley, and to speak up for the natural world that otherwise lacks a voice.
This report is a result of tremendous volunteer energy. People concerned about the future of this valley have lent their support in many ways. In the preparation of this report, we'd like to thank Bart Robinson for his vision and initiative, and for his editorial advice and assistance. We also would like to thank the following individuals for reviewing and commenting upon a draft copy of the report: Mike McIvor, Stephen Herrero, Karsten Heuer, Jeff Gailus, Karin Herrero, Gareth Tompson, Peter Poole, Frank Liszczak.
We thank the following organizations for contributing what funds they could: BowCord, Bow Valley Naturalists, Canadians for Wildlife Corridors, Canadian Parks and Wilderness Society, and UTSB Research.
SECTION ONE - INTRODUCTION
SECTION TWO - METHODS
SECTION THREE - RESULTS AND DISCUSSION
3.0 Results and discussion
SECTION FOUR - CONCLUSIONS
SECTION FIVE - LITERATURE AND PERSONAL COMMUNICATIONS
For much of the last decade, the design and viability of wildlife corridors in the Bow Valley have been topics of much discussion and concern for local and regional non-profit organizations, scientists, conservation-minded individuals and government agencies. In response, government bodies that have jurisdiction over wildlife and land use in the Bow Valley issued a science-based set of guidelines and standards for wildlife corridor and habitat patches in 1998. The government agencies included the Town of Canmore, the Municipal District of Bighorn, Banff National Park and the Government of Alberta.
Jacob Herrero Environmental Consulting and Geoworks Environmental Consulting and GIS were retained by several not-for-profit, citizen organizations to use these government guidelines and standards as the basis for assessing the design and functionality of the wildlife corridors and habitat patches that have been designated in the Southern Canmore Region. Because the TransCanada Highway and the CPR mainline act as potential barriers to wildlife movement, the Southern Canmore Region is at present a significant and apparently viable movement corridor for wildlife species moving between the Kananaskis Valley and Banff National Park in the Bow Valley. All other wildlife movement routes through the Bow Valley between these two locations require a difficult and dangerous crossing of the TransCanada Highway, the CPR tracks, the 1A Highway and the Bow River.
The Southern Canmore Region is a 10 km-long and about 1.5 km-wide strip of predominantly forested land that stretches from the Wind Valley Natural Area to the Canmore Nordic Centre Provincial Park. It is bounded on one side by steep mountain slopes and on the other by the TransCanada Highway and the CPR mainline. Although much of the region is currently undeveloped forest, it will undergo radical change in the near future. Canmore is currently experiencing explosive urban growth, and the residential population is predicted to increase from 10,000 to 30,000 over the next 15 years (Town of Canmore 1998). Figure 1.0-A shows a total estimated population of 20,000 (residential, visitor overnight, and day use) is predicted to be reached in the Southern Canmore Region by 2015. Considering residential population alone, this is the equivalent of adding one-and-a-half Banff townsites to the Bow Valley.
Past and current wildlife studies and sightings demonstrate that the South Canmore Region is both a seasonal home and movement corridor for a number of important ungulates and carnivores. At least two at risk species in Alberta, grizzly bears and wolverines, have been recorded in and around the area (AEP 1996), as well as several other carnivore species of regional management concern, including lynx, cougar and wolves. Important elk and bighorn sheep habitat also is located within the Southern Canmore Region (BCEAG 1999).
The mountain slopes in the Southern Canmore Region are mainly in the Bow Valley Wildland Park, administered by the Province of Alberta. The valley bottom, which is more useful to both people and wildlife, is mainly administered by the Town of Canmore.
Figure 1.0-A Projected Build-out Populations in the Southern Canmore Region
The terms of reference issued for this project were as follows:
The Banff-Bow River Valley is one of the very few low-elevation valleys that cuts east-to-west through the north-to-south trending front ranges of the Canadian Rocky Mountains. Largely because of its low elevation and climate, much of the valley bottom is dominated by montane plant communities. Such montane habitat is rare – it comprises only two to ten per cent of the Canadian Rockies, and less than four per cent of Banff National Park (Gadd 1995; Parks Canada 1997) – and it is essential as winter habitat for elk, deer and bighorn sheep, and as territory for the carnivores that rely on these prey species.
To remain healthy and viable, individual animals have to travel – in some cases over great distances – to eat, to establish home territories, and to find mates that will ensure genetic variability among the population as a whole. Habitat fragmentation, generally the result of human activity, can make such travels difficult or impossible, and whole populations of animals can become isolated, trapped "on islands of natural habitat in a sea of human development" (Janzen 1986). Small, isolated populations face the possibility of extinction, which in turn increases the possibility of species extinctions and the resultant loss of biological diversity.
The Banff-Bow River Valley has been acknowledged as significant for both local and regional wildlife movement. At the same time, there has been general acknowledgement that current and future developments impede such movement – with adverse ecological effects. According to a 1994 report to the Bow River Valley Corridor Task Force, "there is widespread concern within the scientific community that cumulative adverse affects may lead to permanent loss of some and perhaps most large mammalian and other sensitive wildlife species in the Bow River Valley." (Paquet, P.C., Gibeau, M.L., Herrero, S., Jorgenson, J. and J. Green 1994). Further, Wildlife Corridor and Habitat Patch Guidelines for the Bow Valley (BCEAG 1998) states that "the maintenance of viable movement corridors is necessary to mitigate fragmentation of wildlife habitat and populations" (BCEAG 1998), and that the Bow Valley around Canmore constitutes a critical component of the Rocky Mountain Ecosystem because it "provides a vital linkage corridor for large mammals between the Kananaskis Valley, Banff National Park and areas to the north." Gibeau (pers. comm. 1998) and Paquet (pers. comm.1998) have agreed that the Bow Valley near Canmore is a "critical cross-roads" for wide-ranging mammals as they move north and south as well as east and west through the Rockies looking after their daily, seasonal and dispersal needs.
Aside from its importance to wildlife, the Banff-Bow River Valley also contains Canada’s prime transportation corridor. It is also the gateway to four Canadian Rocky Mountain National Parks, and provides urban habitat for two tourist centers, one of which – Canmore, and specifically the Southern Canmore Region – contains one of the most desirable large resort properties currently available in North America (Calgary Herald, 2000 ). Thus, Canmore finds itself in a challenging position that has international implications. Just as the Banff-Bow River Valley is a "critical crossroads" for the increasingly fragmented wildlife populations of the Rockies, it also represents "perhaps the greatest threat to the entire [Yellowstone to Yukon] landscape because human activities in this critical valley may completely divide the bioregion" (Tabor 1996).
In sum, for the sake of the continued viability of local and regional populations of both ungulates and carnivores, and for the sake of the ecological integrity of the Canadian Rockies, it is critical that the human population of the Banff-Bow River Valley find ways to accommodate the needs of other species in the valley. Encouragingly, by their endorsement of the BCEAG guidelines, as well as by other actions and statements, the major land management agencies, as well as the major developers in the valley, have explicitly committed themselves to the principle of functional corridors. The BCEAG guidelines, as approved by the concerned agencies, lay out the minimal standards for functional corridors.
The concept for BCEAG was conceived during the Natural Resource Conservation Board (NRCB) hearings of 1992. In its decision report, the NRCB recognized the importance of regional ecosystem management for the Bow Corridor and recommended the formation – "with some urgency" – of a Bow Valley Planning and Advisory Committee (BPAC) to "coordinate [current and future planning efforts] and provide advice to decision makers and the public" (NRCB Decision Report, 12.2 1992). One of the recommended BPAC subcommittees was a "Regional Ecosystem Advisory Group (REAG)." The same report delineates the tasks and goals for the subcommittee, and outlines a number of "matters that should be referred to the proposed Regional Ecosystem Advisory Group for review." One of those matters was "the locations and widths of corridors to be set aside for wildlife movements" (NRCB Decision Report, 10.5.2 1992).
BCEAG was formed in September 1995, essentially by partnering the NRCB-recommended REAG membership with the NRCB-recommended REAG mandate. The membership included the Municipal District of Bighorn, Town of Canmore, Banff National Park and the Alberta Provincial Government. As described in Guidelines for Human Use Within Wildlife Corridors and Habitat Patches in the Bow Valley (Banff National Park to Seebe) (BCEAG 1999), the partnership’s overarching goal is "to facilitate the coordination of responses to environmental and resource issues in the Bow Valley." Its specific objectives are:
In 1998, in partial fulfillment of those objectives, a team of four BCEAG members – Bill Brown for the Town of Canmore, Greg Birch for the Municipal District of Bighorn, Jon Jorgenson for the Provincial Government, and Karsten Heuer for Parks Canada – developed a science-based framework for the design and evaluation of wildlife corridors in the valley. The guidelines defined "a consistent approach which each of the land management jurisdictions in the Bow Valley will implement when handling development applications where there is potential for impacts on wildlife corridors" (BCEAG 1998).
The guidelines, as published in March 1998, were approved by the Town of Canmore, the Municipal District of Bighorn, Banff National Park, Alberta Environmental Protection, and Alberta Agriculture, Food and Rural Development. The Town of Canmore subsequently incorporated the BCEAG guidelines, by resolution, in the Town of Canmore Municipal Development Plan, a document that "provides an updated and comprehensive set of the major policy directions that will guide future growth in Canmore" (Town of Canmore MDP 1998). In 1999, the guidelines received a special Alberta Premier’s Award for Excellence, which acknowledged them for being "the first multi-jurisdictional initiative to protect wildlife corridors in Alberta," and for providing "clear and consistent standards for wildlife corridor design, and for acceptable development activities in and near these corridors"( www.gov.ab.ca/POA).
The existing secondary and primary multi-species wildlife corridors in the Southern Canmore Region were developed based on parameters recommended by Three Sisters Resorts in 1991. The Three Sisters Resorts approach to wildlife corridor design focused on the spring through fall requirements of deer and elk. By contrast, the BCEAG approach is a multi-species one that considers the four-season requirements of all species, including those that are wide-ranging and generally wary of human development and activities (e.g. wolves).
Three Sisters Resorts approach: designated secondary corridors
The 183 m minimum width of the existing secondary corridors was based on minimum hiding cover requirements for two wildlife species: deer and elk (Three Sisters Resorts 1991). In its 1991 report (p. 11), to the Natural Resources Conservation Board (NRCB), Three Sisters Resorts stated:
Thomas, the scientist cited by Three Sisters Resorts, was the technical editor of the handbook Wildlife Habitats in Managed Forests: the Blue Mountains of Oregon and Washington, published in 1979 by the U.S. Department of Agriculture. The purpose of the handbook was to assist U.S. public forest managers in the protection and enhancement of wildlife habitat on state and federal lands where timber harvest, particularly clear-cut logging, occurs. Three Sisters Resorts used information in the handbook as the rationale for the width of the existing secondary and primary corridors in the Southern Canmore Region. In the handbook "183 meters" is referenced twice:
The application of these two parameters results in a patchwork of cover (forest) and forage (clearcuts), each no less than 183 m across. Such a patchwork – intended to space logging cutblocks in such a way that there was sufficient forest cover between clearcuts – is considered an appropriate strategy for managing deer and elk habitat in coniferous forests. The configuration assumed a remote forestry setting with minimal human activity (Thomas 1979).
Thomas (1979) does not suggest that such a configuration of cover and forage is suitable for a linear wildlife movement corridor for elk or deer (or any other species). Nevertheless, Thomas’s configuration became the empirical basis for the 183 m minimum width corridors that were designated in the Southern Canmore Region. Further, there is no mention by Thomas (1979) that it is appropriate to apply such design parameters to an urban setting like Canmore, where secondary corridors exist – or in the future will exist – within a matrix of human development and activity. Thomas (1979) also cautioned against wildlife management based on single species:
Three Sisters Resorts approach: designated primary corridors
The 350 m minimum width recommended by Three Sisters Resorts for primary corridors was based on thermal cover requirements for elk also set forth by Thomas (Three Sisters Golf Resorts 1991), based on work carried out in the Blue Mountains of Washington and Oregon. In his discussion, Thomas noted that:
The lower end of the 12 to 24 hectare (350 m2 to 500 m2) estimate became the scientific rationale used by Three Sisters Resorts for the 350 m width of the designated Primary Multi-Species Corridors in the Southern Canmore Region. Critically, winter conditions were not accounted for. Nor were the requirements of any other species. Again, Thomas (1979) noted that:
It is unknown whether the 350 m wide existing primary wildlife corridors will provide sufficient thermal cover for elk in the Southern Canmore Region during the most critical season: winter. Thomas (1979) noted, significantly, that land management decisions have confounding effects and he does not suggest that summer and spring-fall range thermal cover estimates can be applied in the context of a linear wildlife movement corridor for elk or other species. Further, because the designated secondary and primary corridors were designed specifically for deer and elk, it is unreasonable to expect that they will function adequately for carnivores, which are much more wary of human settlement and activity.
In sum, the designated secondary and primary corridor widths in the Southern Canmore Region that now appear on maps were almost exclusively based on calculations about the needs of elk and deer for hiding cover and summer and spring-fall thermal cover. Further, the calculations were made for forests with ecological, climatic and land use attributes very different from those in the Canmore region. This limits their usefulness of the resulting corridors to other species and raises important questions about their viability. Other important corridor attributes such as slope (i.e. steepness) and length were not considered.
The 183 m width for secondary corridors and 350 m width for primary corridors proposed by Three Sisters Resorts in 1992 were neither accepted nor rejected in the 1992 Natural Resources Conservation Board (NRCB) decision report. Instead, the NRCB stated that, "The Board would recommend to Alberta Forestry, Lands and Wildlife that widths and locations of corridors be reviewed with the full range of species that are expected to make use of each corridor in mind" (NRCB 1992:35 of NRCB website copy).
The corridor-design methodology promoted by BCEAG addressed the obvious limitations of the approach used by Three Sisters Resorts.
However, the BCEAG approach also has weaknesses.
We used the BCEAG scientific and methodological framework to examine and assess the design and functionality of existing corridors and habitat patches in the Southern Canmore Region. The BCEAG methods were chosen because they have a solid scientific base, and are sanctioned by the government institutions responsible for managing wildlife and land use in the Bow Valley. Because the BCEAG guidelines set out minimum acceptable design standards for achieving functional, viable wildlife corridors, they represent the de facto means for determining whether the design (e.g. widths, slopes) of the designated corridors in the Southern Canmore Region is indeed functional.
The methods recommended by BCEAG for assessing and designing wildlife corridors and habitat patches are explained in Wildlife Corridor and Habitat Patch Guidelines for the Bow Valley (BCEAG 1998). The BCEAG document also defines several important terms. In table form, they include:
For this project, we applied the BCEAG design methodology to the primary and secondary corridors in the Southern Canmore Region as delineated on the most recent Alberta Environment digital map (July 2000) available to us.
This is not a comprehensive assessment: owing to limited time and resources, we have had to make several assumptions that in fact warrant further study.
The Wildlife Corridor and Habitat Patch Guidelines for the Bow Valley (BCEAG 1998) set out a step-by-step process that requires minimal specialized wildlife knowledge or experience to apply. The methods were developed for land managers, planners and developers in the Bow Valley. Geographical Information Systems (GIS) are tools that may be used to assist the process.
There are three key parameters or corridor attributes: 1) width-length, 2) topography, and 3) hiding cover. Interaction between the key parameters results in a practical, easy-to-understand approach to wildlife corridor design, assessment and decision making.
The BCEAG design methods apply to primary and secondary corridors and local habitat patches. Presented below are the steps recommended by BCEAG, a summary of each step, and comments with regard to how we performed the analysis. For the complete explanation and rationale for each step please see the BCEAG document.Step 1- Establish Alignment
Summary of BCEAG method
BCEAG recommends that corridors should be as straight as possible and avoid twists, turns, cul-de-sacs and doglegs. Habitat patches should be circular or square in shape rather than long or convoluted in order to maximize their interior resting and feeding potential. The ratio of surface area to perimeter (SA/P) should be less than 0.45.
We based our analysis on the existing configuration of the wildlife corridors and habitat patches as they are currently delineated and shown on Alberta Environment maps. A GIS was utilized to calculate the surface-to-perimeter ratio of the Grassi Lakes Local Habitat Patch.
Step 2 - Establish Width and Length
Summary of BCEAG method
Corridor length and width interrelate. In general, longer corridors need to be wider. The maximum allowable length of a primary corridor connecting two regional habitat patches is 8 km. BCEAG provides a table showing how to calculate corridor width based on corridor length (see Fig. 6 in BCEAG 1998).
The lengths and widths of the primary and secondary corridors were calculated using GIS. Length was measured along the centre axis of each corridor.
Step 3 - Adjust for topography
Summary of BCEAG method
Landscape features such as ridges, ravines and slopes influence wildlife use of corridors and habitat patches. Ridges and benches that separate human developments and wildlife in corridors act as buffers that attenuate human disturbance (e.g. noise and light). Sloping ground without ridges and benches above a development do not perform this function well. Slopes over 25 degrees are inadequate for corridor function. BCEAG provides tables to demonstrate how to adjust corridor width and patch size (see Fig. 7 and 8 in BCEAG 1998).
The Southern Canmore Region is characterized by slopes that rise up from the valley bottom. There are few prominent ridges and benches that run parallel to corridors to attenuate human disturbance. Our analysis of topography was limited to the slope, as this is the defining topographic attribute in the Southern Canmore Region. A 1:50,000 digital elevation model (DEM) was used to determine the angle of slope in the study area. Ground truthing demonstrated that the DEM underestimated the angle of slope.
Step 4 - Adjust for vegetative hiding cover
Summary of BCEAG method
Vegetative hiding cover is used by animals for security purposes. This is an important attribute of corridor design. Hiding cover values (HCV) less than 40 per cent necessitate wider corridors and larger local habitat patch sizes. The diagram and example provided shows the adjustments required (see Fig. 9 in BCEAG 1998). Hiding cover values of less than 10 per cent are not functional for a wildlife corridor.
Hiding cover values within corridors and habitat patches were determined from interpretation of 1999 digital air photos of the Bow Valley in comparison to the Alberta Vegetation Inventory and a habitat map developed by the Eastern Slopes Grizzly Bear Project.
Hiding cover was divided into two broad categories: areas with hiding cover and areas with no hiding cover. The habitat map developed by the Eastern Slopes Grizzly Bear Project showed that almost all areas with tree cover or dense shrub had HCV greater than 40 per cent. Based on this, we classified units of contiguous forest cover or dense shrubland as having HCV over 40 per cent. Areas that are not forested are almost exclusively human-made openings such as golf fairways, aggregate pits and power-line clearings. These areas are practically devoid of hiding cover and were classified as having HCV under 10 per cent. Areas with hiding cover between 10 per cent and 40 per cent are rare.
We feel our approach provides a good estimate of hiding cover values within corridors and habitat patches. However, this approach likely overestimates the amount of hiding cover in areas heavily fragmented by roads and other disturbances on the landscape. This model could be refined by applying the field methods suggested by BCEAG.
This section summarizes the results that were generated with the aid of GIS when the BCEAG scientific and methodological framework was used to assess the designated wildlife corridors and habitat patches in the Southern Canmore Region. The BCEAG approach involves using BCEAG minimum standards to determine if adjustments to corridors and habitat patches are required. The BCEAG document describes the process:
The BCEAG minimum standards are presented in Table 3.0-A.
Table 3.0-A BCEAG minimum standards
It is important to note that deviation from these minimum standards require the application of BCEAG prescribed mitigations , primarily making the corridor wider or the habitat patch larger. As well, there are also certain conditions that cannot be mitigated. For example, slopes greater than 25 degrees are "inadequate for corridor function" (BCEAG 1998:16).
Figure 3.0-A Understanding the BCEAG approach
Table 3.1.1-A Primary Multi-Species Wildlife Corridor Assessment
As per BCEAG procedures, length of a primary corridor is measured from one regional wildlife patch to another. We selected the Wind Valley Regional Wildlife Patch and the Georgetown/Canmore Nordic Centre Regional Wildlife Patch because the route linking these two has the best chance of connecting regional wildlife populations.
As per BCEAG procedures, use the maximum width calculated as the final width for a corridor. If favorable topographic features are present, subsequent calculations are required. (See BCEAG 1998, p. 20).
This corridor is part of a vital movement route for large mammals moving between Banff National Park and the Kananaskis Valley. It is 13.7 km in length and connects two important regional habit patches in the Canmore area. At one end is the Wind Valley, at the other, the Canmore Nordic Centre. It is mainly forested at present. Much of the future growth planned in Canmore will occur parallel to its length, on the downhill side. At full build-out in about 15 years, 20,000 people per day are projected to be near and adjacent to this critical corridor. Wildlife can currently move freely through most of the area planned for future urban development. Once developed, however, there is an assumption that east-west wildlife movements will be displaced into the corridor, resulting in a primary wildlife movement corridor.
The application of the BCEAG methodology to the existing Primary Multi-Species Corridor revealed several serious corridor deficiencies. The most serious of these is that it is too narrow considering its length (Table 3.1.1-A). The maximum length allowed for a primary corridor is 8 km (BCEAG 1998). Corridors exceeding 8 km in length necessitate the addition of local habitat patches to reduce their overall length to under 8 km (BCEAG 1998). The habitat patch should meet BCEAG standards if it is going to be useful to wildlife. If a habitat patch was added near the middle of this corridor, the required width could be reduced from 1150 meters to about 850 meters wide (BCEAG 1998).
Slope analysis showed that the existing Primary Multi-Species Corridor is characterized by steep slopes. Much of the corridor (n=68 %) is sloped between 10° and 24° . This requires adding between 80 and 200 meters to the BCEAG base width, depending on the slope at a particular location (BCEAG 1998). Only two per cent of the corridor is flat (0-4° ); 19 per cent of the existing primary corridor is comprised of slopes greater than 25° . Slopes greater than 25° are not suitable in primary corridors because "they are inadequate for corridor function" (BCEAG 1998:16). Our GIS method underestimated slope.
Slopes greater than 25° are concentrated in two main locations: above the Peaks of Grassi Subdivision and below Wind Ridge (Map 3). The location above the Peaks of Grassi subdivision forms a severe pinch-point in the Primary Multi-Species Corridor and is predicted to compromise its function. It is not possible to shift the corridor downhill because the Peaks of Grassi subdivision is immediately below. Functionally, the Peaks of Grassi subdivision is in the Primary Multi-Species Corridor.
Ninety-one per cent of the existing Primary Multi-Species Corridor is forested, and hiding cover analysis showed that forested areas within this corridor met and exceeded the BCEAG minimum standard for vegetative hiding cover (> 40). Nine per cent of the corridor consisted of openings that failed to meet the BCEAG functionality requirements. Most of these openings are fairways associated with the Stewart Creek Golf Course. The combination of poor hiding cover and steep slopes (> 25° ) creates a potentially serious problem that will increasingly manifest itself in the future as full build-out occurs and displaces wildlife into this area. BCEAG procedures provide a framework for developing mitigations for this critical part of the Primary Multi-Species Corridor.
The BCEAG minimum standards assume no human use in a primary wildlife corridor. BCEAG notes that "habitat abandonment by wildlife due to high levels of human activity is a common occurrence" and "increased contact with humans is directly linked to increased human/wildlife interactions, and in the case of bears is directly linked to increased mortality" (BCEAG 1999: 3). To accommodate either existing levels of human use (e.g. the Stewart Creek Golf Course, sanctioned trails) or predicted future increases in human use (more dog walking, hiking, biking, etc.) as Canmore expands, it would be necessary to exceed the minimum standards set by BCEAG.
Table 3.1.2-A Stewart Primary Wildlife Corridor Assessment
§As per BCEAG procedures, use the maximum width calculated as the final width for a corridor. If favorable topographic features are present, subsequent calculations are required (See BCEAG 1998, p. 20).
The Stewart Primary Wildlife Corridor is intended to provide a wildlife movement route between the Primary Multi-Species Corridor and the Bow Flats Regional Habitat Patch. It is about 1 km long and passes under the TransCanada Highway, which is fenced on both sides.
According to BCEAG evaluation methods, the Stewart Primary Wildlife Corridor has two main deficiencies: lack of hiding cover and insufficient width. Unlike the Primary Multi-Species Corridor, steep slopes are not a problem. However, 51 per cent of the existing Stewart Primary Corridor was classified as non-functional due to the extensive presence of golf course fairways and other developments that lack acceptable vegetative hiding cover.
The shape of the Stewart Primary Wildlife Corridor is unusual. On BCEAG, Three Sisters Resorts and Town of Canmore maps it is a uniform width to the TransCanada Highway. However, on the recent Government of Alberta corridor map (July 2000) it is funnel-shaped – at the TransCanada Highway it is only 19 m wide. Whereas the need to direct animals towards the underpass is understandable, full width (350 m) is necessary to provide an adequate "buffer" against adjacent human activities. For a primary corridor connecting to a regional habitat patch (Bow Flats Regional Wildlife Patch) this security "buffer" (i.e. forest) is particularly important. A uniform width of 350 m to the TransCanada will be extremely important as urban build-out occurs adjacent to this corridor. This narrowing of a primary corridor to 19 m represents a serious map error and should be corrected.
To meet BCEAG minimum standards for hiding cover, the power line right-of-way within this primary wildlife corridor requires special management. When cutting trees that might interfere with power lines, the lower 2 m should be left standing so as to provide hiding cover for wildlife.
The BCEAG minimum standards explicitly assume no human use in a primary wildlife corridor. BCEAG notes that "habitat abandonment by wildlife due to high levels of human activity is a common occurrence" and "increased contact with humans is directly linked to increased human/wildlife interactions and in the case of bears is directly linked to increased mortality" (BCEAG 1999: 3). To accommodate either existing levels of human use (e.g. the Stewart Creek Golf Course, sanctioned trails) or predicted future increases in human use (more dog walking, hiking, biking, etc.) as Canmore expands, it would be necessary to exceed the minimum standards set by BCEAG.
Table 3.1.3-A Wind Valley Primary Wildlife Corridor Assessment
This corridor is intended to connect the Wind Valley with the Bow Flats Regional Wildlife Patch. To use this corridor, wildlife must cross the TransCanada. Currently there is no crossing structure for wildlife. Wildlife mortality near this section of the TransCanada Highway is high.
This area is currently under review. A two-year study focussing on ungulate and snowshoe hare habitat use began in the fall of 1998; it will finish this fall (Wildlife and Company Ltd. 1999). The results of this study are intended to optimally locate this corridor. Large-scale developments are planned in this area.
Providing that the current corridor location is optimal, and providing that the width of the Primary Multi-Species Corridor is increased as per BCEAG minimum standards (Map 2), this primary corridor requires only minor BCEAG prescribed mitigations to reach the BCEAG minimum standards. Hiding cover is generally sufficient and slope is moderate. To meet BCEAG minimum standards for hiding cover, the power line right-of-way within this primary wildlife corridor requires special management. A 60 to 80 m wide power line right-of-way crosses this corridor near the TransCanada. When cutting trees that might interfere with power lines, the lower 2 m should be left standing to provide hiding cover for wildlife.
Currently there is no structure to facilitate the movement of wildlife across the TransCanada Highway at the terminus of this corridor. The TransCanada Highway is both a barrier to wildlife movement and a source of wildlife mortality. The functionality of this primary corridor linking the Wind Valley and Bow Flats regional habitat patches would be improved with an appropriate crossing structure.
The BCEAG minimum standards assume no human use in a primary wildlife corridor. BCEAG notes that "habitat abandonment by wildlife due to high levels of human activity is a common occurrence" and "increased contact with humans is directly linked to increased human/wildlife interactions and in the case of bears is directly linked to increased mortality" (BCEAG 1999: 3). To accommodate either existing levels of human use or predicted future increases in human use (more dog walking, hiking, biking, etc.) as Canmore expands, it would be necessary to exceed the minimum standards set by BCEAG.
Secondary corridors are narrower than primary ones, and are intended for smaller wildlife species (e.g. pine marten, red squirrel, hairy woodpecker) and those that acclimate more readily to human activities and artifacts (e.g. elk, coyote). They should provide sufficient hiding cover to accommodate movement (BCEAG 1998). Secondary corridors are important links to larger habitat patches, and form an integral part of a corridor network.
Table 3.2.1-A Grassi Secondary Wildlife Corridor Assessment
Proposed fairways were derived from Three Sisters Resorts maps (UMA Engineering Ltd. 1998 and 1999).
HCVs do not include ponds, roads, cart paths and other developments associated with golf course development.
As per BCEAG procedures, use the maximum width calculated as the final width for a corridor. If favorable topographic features are present, subsequent calculations are required (See BCEAG 1998, p. 20).
This corridor connects the Primary Multi-Species Corridor with the South Canmore Local Habitat Patch, across the Bow River. It is 1.35 km long.
The lower, west boundary of the Grassi Secondary Corridor is delineated by an existing subdivision (Prospects) and hotel facility (Residence Inn). The east boundary is undeveloped at present. Three Sisters Resorts plans show development on both sides in the future. The recently constructed but not yet open Three Sisters Parkway passes through this corridor. Three Sisters Resorts has proposed extensive golf course development within the Grassi Secondary Corridor.
The Grassi Secondary Corridor does not currently meet any BCEAG minimum standards for a secondary wildlife corridor. It is particularly deficient in width and hiding cover and is not presently viable as a corridor. Based on hiding cover values, 47 per cent of this corridor is currently non-functional because it consists of cleared openings (e.g. mine scar, roads, power line right-of-way, etc.). The addition of the fairways that Three Sisters Resorts proposes on its 1998 and 1999 maps (UMA 1998 and 1999) would only add to the corridor’s shortcomings by increasing the cleared, non-functional area to 68 per cent.
Re-establishing vegetative hiding cover such that BCEAG minimum standards (> 40) are met would improve the functionality of this corridor. If this is not possible, vegetative hiding cover should be re-established to at least a value of 10, and the corridor then widened according to BCEAG procedures, which would result in a corridor about 438 meters wide. (This assumes that the added area is forested to a hiding cover value > 40.) These mitigations are necessary if it is to function as a secondary corridor.
To meet BCEAG minimum standards for hiding cover, the power line right-of-way (63 - 83 m wide) within this wildlife corridor requires special management. When cutting trees that might interfere with power lines, the lower 2 m should be left standing so as to provide hiding cover for wildlife.
The BCEAG minimum standards for secondary wildlife corridors assume no human use. This is particularly relevant to this corridor because it is currently bisected by a future high-traffic-volume road and adjacent to a subdivision and large hotel. BCEAG notes that "habitat abandonment by wildlife due to high levels of human activity is a common occurrence" and "increased contact with humans is directly linked to increased human/wildlife interactions…and in the case of bears is directly linked to increased mortality" (BCEAG 1999: 3). To accommodate either existing levels of human use or predicted future increases in human use (more dog walking, hiking, biking, etc.) as this area develops, it would be necessary to exceed the minimum standards set by BCEAG.
Table 3.2.2-A Three Sisters Creek Secondary Wildlife Corridor Assessment
Proposed fairways were derived from Three Sisters Resorts maps (UMA Engineering Ltd. 1998 and 1999).
As per BCEAG procedures, use the maximum width calculated as the final width for a corridor. If favorable topographic features are present, subsequent calculations are required. (See BCEAG 1998, p. 20).
The Three Sisters Secondary Wildlife Corridor is "Y" shaped. From the Primary Multi-Species Corridor, there is a west and an east route towards the Bow River. The west route is 1.8 km long and the east route is 2.1 km. This corridor links the Primary Multi-Species Corridor with the South Canmore Local Habitat Patch.
Both the east and west routes fail to meet BCEAG standards for a secondary corridor. The lack of adequate hiding cover is the main deficiency for both. Currently, about 40 per cent of both the west and east routes comprise cleared areas that lack hiding cover acceptable in a wildlife movement corridor. This renders both corridors non-functional according to BCEAG standards. The addition of proposed golf course fairways would further compromise their functionality. The combination of existing clearings combined with proposed fairways would create the unacceptable situation shown on Map 1.
Similar to Grassi Secondary Corridor, re-establishing vegetative hiding cover to BCEAG minimum standards (> 40) would improve the functionality of this corridor. If this is not possible, it can be widened according to BCEAG procedures, which would result in a corridor about half a kilometer wide. (This assumes that the added area is forested to a hiding cover value > 40.) These mitigations are necessary if these corridors are to function as secondary corridors.
To meet BCEAG minimum standards for hiding cover, the power line right-of-way within these corridors requires special management. When cutting trees that might interfere with power lines, the lower 2 m should be left standing so as to enhance hiding cover for wildlife.
The BCEAG minimum standards assume no human use in a secondary wildlife corridor. The east corridor currently hosts a part of the Stewart Creek Golf Course and an aggregate rock quarry. BCEAG notes that "habitat abandonment by wildlife due to high levels of human activity is a common occurrence" and "increased contact with humans is directly linked to increased human/wildlife interactions… and in the case of bears is directly linked to increased mortality" (BCEAG 1999: 3). To accommodate either existing levels of human use or predicted future increases in human use (more dog walking, hiking, biking, etc.) as Canmore expands, it would be necessary to exceed the minimum standards set by BCEAG.
Local habitat patches are intended to meet the food, rest and water needs of wildlife for a short period of time, enroute to a larger regional habitat patch. They need to provide sufficient interior space and hiding cover so that animals can use them undisturbed by human activities (BCEAG 1998).
Table 3.3.1-A Grassi Lakes Local Habitat Patch Assessment
As per BCEAG procedures, use the maximum width calculated as the final width for a corridor. If favorable topographic features are present, subsequent calculations are required. (See BCEAG 1998, p. 20)
The Grassi Lakes Local Habitat Patch is the northwestern terminus of the Primary Multi-Species Wildlife Corridor. This is currently the only designated habitat patch in the Southern Canmore Region. It is located at the base of Ha Ling Peak and is bordered to the north by a hydroelectric reservoir known as the Rundle Forebay. Quarry Lake, a popular recreation area, is located adjacent to its eastern boundary. Wildlife movement studies are currently ongoing in this area.
There is discussion about providing a crossing structure over the Rundle Forebay. This would be positive for wildlife movements. In 1999 several wolves moved from the Wind Valley through the Southern Canmore Region to this area and then turned around at the Rundle Forebay. It is a major barrier to wildlife movement and further reduces the effectiveness of the Primary Multi-Species Wildlife Corridor.
The Grassi Lakes Local Habitat Patch is 1.43 km2. According to BCEAG standards, a local habitat patch needs to be a minimum 4.5 km2 to function. As was the case with the secondary corridors, open clearings are too abundant and greatly reduce hiding cover effectiveness. As this is a popular recreational area, hiding cover for wildlife here is very important. The BCEAG minimum standards assume no human use in a local habitat patch. BCEAG notes that "habitat abandonment by wildlife due to high levels of human activity is a common occurrence" and "increased contact with humans is directly linked to increased human/wildlife interactions…and in the case of bears is directly linked to increased mortality" (BCEAG 1999: 3). To accommodate either existing levels of human use or predicted future increases in human use (more dog walking, hiking, biking, etc.) as Canmore expands, it would be necessary to exceed the minimum standards set by BCEAG.
This assessment shows that the Primary Multi-Species Wildlife Corridor through the Southern Canmore Region fail to meet the minimum standards for a functional, viable corridor as set by BCEAG. This failure has the potential to severely impair the movement of wildlife in the Bow Valley between the Kananaskis Valley, Banff National Park and beyond, and could have adverse effects on the regional populations of wide-ranging, wary species such as wolf, grizzly bear, wolverine and lynx. The grizzly bear and wolverine may be at risk of extirpation (i.e. extinction) in Alberta (AEP 1996).
The failure to provide for a viable primary multi-species corridor through the Southern Canmore Region would contribute to further impairment of the Bow Valley ecosystem. The Ecological Outlooks Project for the Banff-Bow Valley Study (Banff-Bow Valley Task Force 1996) identified important environmental concerns in the Bow Valley:
Since 1996, Banff National Park has expended considerable resources to facilitate wildlife movements in the Bow Valley between the Banff townsite area and the Town of Canmore. Three specific actions have included:
One key strategic goal of Banff National Park is to maintain "connectivity for large carnivores, and other wildlife in the park and on surrounding lands" (Banff National Park Management Plan 1997). In the Bow Valley, this important goal cannot be achieved without the cooperation of Canmore. Situated adjacent to Banff National Park, in critical montane wildlife habitat, Canmore is projected to grow from about 10, 000 to 30, 000 residents in the next 15 years. Decisions made in Canmore profoundly effect the ecological integrity of the Bow Valley and the movement patterns and possible survival of regional wildlife species. Canmore's Municipal Development Plan indicates that the Town of Canmore is committed to the provision of viable wildlife movement corridors within the municipality, including the Southern Canmore Region, based on the BCEAG guidelines and standards.
The members of BCEAG – The Town of Canmore, Government of Alberta, the District of Bighorn, and Banff National Park – all recognize the vital role wildlife movement corridors play in the Bow Valley and issued a set of minimum standards necessary to achieve functional corridors. Most of the designated corridors in the Southern Canmore Region require substantial mitigations to meet these minimum standards. Given that in about 15 years the total potential human population (residential, visitor overnight, and day use) in the Southern Canmore Region alone could reach an estimated 20, 000 people, it would be necessary to not only meet the minimum standards but to exceed them to achieve viable corridors.
This assessment, using the BCEAG scientific framework, identified some of the main deficiencies associated with the wildlife corridors in the Southern Canmore Region. The next step is to refine the assessment and develop solutions based on the BCEAG guidelines and standards to address these deficiencies. This requires the involvement and commitment of various stakeholders.
SECTION FIVE LITERATURE CITED AND PERSONAL COMMUNICATIONS
|Back to Wildlife Corridors Homepage|