Jade Boulder Sheep Project

Habitat Use and Movement of the Dome Mountain Stone’s Sheep, Prepared by Tahltan Wildlife Department, Tahltan Guide & Outfitter Association, Shaun FreemanSDF Environmental, and Norm MacLean, LGL Limited

Above: Clements Brace observing Stone sheep, seen in the background.

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ADULT EWES Collared and tracked until from 2017 until August 2020. A combination of Tahltan knowledge and local guide outfitter knowledge had identified a sensitive area where the Dome Mountain Stone’s sheep made an annual movement during summer across the Jade-Boulder Road (JBR). This observation was supported by the results of an aerial inventory of sheep (Rescan 2007) conducted for a proposed mining development which documented that the numbers of sheep present between the winter and summer suggested that the majority of the population made this movement. The use of the JBR for proposed industrial development suggested that it may become a barrier to sheep and increase the vulnerability of the population to predation as well as limit access to key life requisites if traffic increased or the road was developed further. In 2017, the Tahltan Guide & Outfitters Association (TGOA) and Tahltan Central Government (TCG), with substantial contribution from the Wild Sheep Foundation and others, set out to investigate and understand the details associated with this annual sheep movement and identify seasonal habitat. We also investigated the current traffic activity of the JBR on sheep as well as the health of the population, and other threats such as predation. Ten adult ewes were collared and subsequently tracked until August 2020. The movement and use of habitat was documented from the tracking of the ewes and this information was supplemented with an assessment of habitat including documentation and evaluation of nutrients and forage quality in the vegetation and soil, as well as documentation of nutrients and fecal cortisol in sheep pellets as an indicator of nutritional health and stress.

Levels of traffic were inventoried using remote cameras along the JBR during the period that sheep were known to cross the road. Sheep health was assessed from hair, tissue and blood samples taken from sheep during the capture in February 2017.

Mortalities of the collared sheep were evaluated for cause through the duration of the project. The sheep were inventoried in the summer of 2018 using similar methods as the inventory of 2007 (Rescan 2007).

Population was comparable between the two summer surveys, 167 being observed in 2007 and 151 in 2018. Distribution of the sheep was nearly identical between the 2007 and 2018 results with nearly all being recorded on the northside of the JBR and within a few key survey units.

There were 47 lambs per 100 ewes (or ewe like sheep) and 50 rams per 100 ewes observed in 2018, numbers that indicate a sustainable herd.

The Dome Mountain sheep selected seasonal habitat that had attributes that were different proportionality to the attributes available in the seasonal study area. Specifically, they selected higher elevation alpine and subalpine habitats and vegetation communities that tended to be drier, open and grass dominated. Home ranges (based on the 80% kernel cores seasonal habitat) were much smaller in winter (average 229.4 ha, SD=78.3) than summer (average 711.5 ha, SD=142.6) and sheep tended to be within 150 m of escape terrain (modelled at between 30° and 40° to 80° slopes) with a selection for warmer aspects in winter and cooler aspects in summer. These observations are all consistent with the findings of sheep habitat in other locales of their distribution (e.g., Parker and Walker 2007, Hengeveld, and Cubberley 2011, Walker 2005).

Of the ten collared sheep, eight crossed the JBR, one sheep was injured and died in summer 2017, complicating evaluation of her movements. Another was captured north of the JBR, and she remained there for the duration of the project. Seven of the collared sheep used a significant mineral lick identified in the northwest of the study area. The results indicated that both the lick and soil north of the JBR were significantly higher in concentration of most micro and macro minerals when compared to the soils in the lambing and winter range south of the JBR. Concentrations were also higher in the mineral lick than had been documented for nutrients from licks associated with Stone’s sheep range in other areas of their distribution in BC (e.g., Ayotte et al 2006, Parker and Ayotte 2004), particularly concentrations of calcium and magnesium. The concentrations of minerals in forage vegetation on both sides of the JBR were statistically similar for most minerals, although higher in concentration on the summer range to the north, with some key minerals being significantly higher in grass vegetation. The concentration of minerals in fecal pellets were higher than pellet groups at the mineral lick and on summer range. The concentrations declined significantly from July through to May, suggesting sheep were losing minerals throughout the year when on winter and lambing range. Health investigations

(Thacker 2020) suggest that cobalt, copper, and zinc were deficient in the Dome Mountain sheep, and while cobalt and copper were slightly lower in concentration in the vegetation, zinc was higher in the Dome Mountain samples than reported from other locations (i.e., Parker and Ayotte 2004), although concentrations were comparable or higher in the soil of the significant lick when compared to other areas. Selenium was generally low or at non detectable rates (less than 0.05 mg/kg) in the soil sampled, however sheep were not deficient in this mineral (Thacker 2020), suggesting suitable concentrations for sustaining sheep were available. Terrestrial lichen was the only medium of vegetation or soil that had detectable concentrations of selenium and Stone’s sheep have been documented foraging on lichen in small quantities (Valdez and Krausman 1999), possibly indicating it has importance for supplementing this dietary requirement in sheep.

Above: Jarett Quock locating Stone sheep collars.

The vegetation communities on both the north and south sides of the JBR used by sheep were similar and dominated by Altai fescue, alpine sweet grass, and two-toned sedge as well as other grasses and sedges with a greater cover of willow and scrub birch associated with the lower elevations of sheep’s core seasonal ranges. The key sheep forage vegetation including grass/sedge which has been identified as dominant in Stone’s sheep diet (Valdez and Krausman 1999) and willow also a substantial component, changed in forage quality seasonally. During the winter the quality of grass (dominated by Altai fescue) was poor when compared to requirements of other ungulates (i.e., deer) and had crude protein of below 5% less than the threshold of 7% identified as the minimum for maintenance of these ruminants (Wallmo et al 1977) although digestibility was greater than the more protein rich willow with lignin content of 4.4% in the grass. The forage quality remained poor into the early May lambing period, however and considering its proximity to the lower threshold of maintenance and the potential deficit sheep are experiencing in micro and macro nutrients, their dependence on reaching resources across the JBR are likely of great urgency after lambing. By July, the forage quality had rebounded and grass on summer range increase to 17.8% crude protein, sugar of 13.1%, crude fat of 3.4% and lignin of 3.6%, exceeding values for the other vegetation sampled.

The results from tracking the collared sheep identified that the majority of the sheep cross the JBR at a location where escape terrain is most continuous, and this condition exists at only one location along the JBR. This area was identified, and the intent is to protect it as a candidate protected area through the ongoing Tahltan Stewardship Initiative (TSI) and land use planning process.

An additional ATV trail was also identified that crossed the sheep corridor south of the JBR and similar protection is being sought for this area. Dome Mountain sheep cross the JBR annually and they were observed heading north between May 26 to July 9 and then returning south as early as August 3 to as late as October 12. Sheep took less time to cross the road in spring/early summer than late summer/early fall. Their period of crossing was shorter (average 25.3 days, SD=4.9) heading north than south (average 44.3 days, SD=3.8) and they make fewer attempts to travel north (24 crossings observed) than south (32 crossings observed). Sheep tended to cross during daylight hours with 67% and 72% of the crossings during the day for north and south crossing respectively.

ANNUAL DOME MOUNTAIN SHEEP JADE-BOULDER ROAD CROSSING – OBSERVED RESULTS

TRAVELING

RETURNING North South

May 26–July 9 August 3–October 12

25.3 days

AVG. CROSSING PERIOD (SD=4.9)

24

CROSSING ATTEMPTS OBSERVED

44.3 days

AVG. CROSSING PERIOD (SD=3.8)

32

CROSSING ATTEMPTS OBSERVED

67% 72%

DURING DAYLIGHT DURING DAYLIGHT

The traffic on the JBR generally begins in late May or early June when the road opens as the snow melts and remains open until snow accumulations close it again in October. During the north sheep crossing period the vehicle traffic is predominantly industrial and over three years averaged two Vehicles Per Day (VPD [SD = 0.2]), while the south is more than double having averaged five VPD (SD=1.2) with the additional traffic observed associated to the recreational activity which was mostly hunting. The stress levels of the Dome Mountain sheep, as indicated by fecal cortisol concentrations, were significantly higher when crossing the road in spring (578.3 ng/g, SD=597.5, n=26) than during the winter (41.0 ng/g, SD=8.6, n=20) when they were moving less, having fewer social interactions, and kilometres away from human disturbance. No data was available for late summer/fall to compare. There was also a lower concentration of fecal cortisol from pellet groups sampled north of the JBR (465.0 ng/g, SD=589.2, n=17) than south (792.3 ng/g, SD=585.4, n=9) suggesting sheep were settling down once they made the crossing although this difference was not statistically significant.

These results indicate that the action of moving from lambing range to summer range, crossing the JBR when it is supporting low traffic volumes of two VPD pose considerable stress to the sheep, there exists additional variables such as behaviour, undetected lamb predation and land use south of the JBR that may contribute to sheep stress that warrant further investigation. However, during the time sheep cross the JBR they are at elevated stress levels, and this can only be exacerbated from increased activity along the JBR.

During the three years of the project seven of the ten collared sheep died. An annual mortality of an average of 20% per year for the duration of the collar monitoring was observed from the sheep. This mortality was like the results observed from other studies in the sheep range, for example 18.5% mortality was observed in the Besa and Prophet River drainages of BC by Hengevld and Cubberley (2011).

It was concluded that the Dome Mountain Stone’s sheep are a viable, healthy, and productive population and the population is currently sustainable with the quality and availability of the habitat on their range.

The sheep population is dependent upon accessing the mineral resources north of the JBR including area associated with the volcanic geology as well as the significant lick. Without access to these minerals, it is unlikely that the sheep can meet their nutrient requirements and would likely suffer from reduced fitness from a nutrient deficit, potentially decreasing their sustainability. “The sheep population is dependent upon accessing the mineral resources north of the JBR including area associated with the volcanic geology as well as the significant lick. Without access to these minerals, it is unlikely that the sheep can meet their nutrient requirements [...] potentially decreasing their sustainability.”

Management of the JBR movement corridor would include the following regulation within the delineated corridor:

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No daytime travel exceeding two VPD to occur between May 25–July 10 and between August 1–September 30. Use of monitored convoys after dark may be a provision to allow more traffic through if required;

Maintain a controlled speed of 20 km/h through the corridor, no stopping permitted during May 25–July 10 and August 1–September 30 in the corridor. Provisions for noise reduction (e.g., enhanced mufflers/noise suppression) of industrial traffic may be included;

SEVERAL RECOMMENDATIONS WERE MADE INCLUDING DETAILED MANAGEMENT OF THE JBR AND THE SIGNIFICANT LICK IDENTIFIED, SPECIFICALLY:

Management of the significant lick and area (2 km) around it and connectivity to summer range would include the following:

No development including vegetation removal, development of trails and roads, mining, exploration, or timber development.

No motorised activity between June 1 –October 31 within the area designated; and,

Between June 1–October 31 helicopters maintain a 2,000 m horizontal and 400 m vertical separation from the lick consistent with BC Mountain Goat Management Team (2010) recommendations for goat.

27 Maintain roadway no greater than one lane in width and no vegetation clearing beyond a minimum right of way within the corridor. Radio controlled traffic is recommended to avoid conflict between directional traffic through the corridor;

Road improvement, maintenance, or other construction within the corridor is not to occur during the sensitive period of May 25 –July 10 and August 1–September 30;

ATV access/use restricted to the JBR between May 25–July 10 and August 1 – September 30 within the corridor;

Air traffic is to maintain a 2,000 m horizontal or 400 m vertical separation from the corridor between May 25–July 10 and August 1–September 30; and,

No camping within 2,000 m of the JBR crossing location.

Similar recommendations were made to manage an ATV exploration trail that also crossed the sheep movement corridor south of the JBR. Progress on implementing these recommendations is currently being made.

Regarding management actions, a number of the access conditions identified above and previous, were used by the TCG in establishing industrial users’ road access permit (Special Use Permit) conditions for the JBR. The work was done through a working group with the Province of British Columbia. There are now legal permit conditions for industrial users on the road. In 2022, the working group will review the implementation, monitoring, and compliance of the permit conditions to determine adjustments for the 2022 field season.

Through the Tahltan BC Fish and Wildlife Working Group, TCG has included ATV alpine elevational restrictions and closure of the Dome Mountain trail for licenced hunters. A decision will be made this winter on the implementation of the regulation changes.

ADDITIONAL WORK AND RESEARCH RECOMMENDED FROM THE RESULTS OF THIS STUDY INCLUDE:

Develop a habitat model from these results for regional use;

Characterize lamb predators;

Investigate the Dome Mountain sheep diet to quantify composition;

Expand fecal cortisol monitoring;

Develop a forage biomass estimate to allow calculation of carrying capacity and long-term monitoring of changes in the vegetation community; and,

Conduct ongoing population monitoring.