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Recovery Strategy for Dun Skipper (Euphyes vestris vestris) in Canada - 2017 [Proposed]

Part 1 – Federal Addition to the Recovery Plan for Dun Skipper (Euphyes vestris) in British Columbia, prepared by Environment and Climate Change Canada

Preface

The federal, provincial, and territorial government signatories under the Accord for the Protection of Species at Risk (1996) agreed to establish complementary legislation and programs that provide for effective protection of species at risk throughout Canada. Under the Species at Risk Act (S.C. 2002, c.29) (SARA), the federal competent ministers are responsible for the preparation of recovery strategies for listed Extirpated, Endangered, and Threatened species and are required to report on progress within five years after the publication of the final document on the SAR Public Registry.

The Minister of Environment and Climate Change is the competent minister under SARA for the Dun Skipper vestris subspecies and has prepared the federal component of this recovery strategy (Part 1), as per section 37 of SARA. To the extent possible, it has been prepared in cooperation with the Province of British Columbia (B.C.), as per section 39(1) of SARA. SARA section 44 allows the Minister to adopt all or part of an existing plan for a species if it meets the requirements under SARA for content (sub‑sections 41(1) or (2)). The Province of British Columbia provided the attached recovery plan for the Dun Skipper (Part 2) as science advice to the jurisdictions responsible for managing the species in British Columbia. It was prepared in cooperation with Environment and Climate Change Canada.

Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this strategy and will not be achieved by Environment and Climate Change Canada, or any other jurisdiction alone. All Canadians are invited to join in supporting and implementing this strategy for the benefit of the Dun Skipper vestris subspecies and Canadian society as a whole.

This recovery strategy will be followed by one or more action plans that will provide information on recovery measures to be taken by Environment and Climate Change Canada and other jurisdictions and/or organizations involved in the conservation of the species. Implementation of this strategy is subject to appropriations, priorities, and budgetary constraints of the participating jurisdictions and organizations.

The recovery strategy sets the strategic direction to arrest or reverse the decline of the species, including identification of critical habitat to the extent possible. It provides all Canadians with information to help take action on species conservation. When critical habitat is identified, either in a recovery strategy or an action plan, SARA requires that critical habitat then be protected.

In the case of critical habitat identified for terrestrial species including migratory birds SARA requires that critical habitat identified in a federally protected areaFootnote 1 be described in the Canada Gazette within 90 days after the recovery strategy or action plan that identified the critical habitat is included in the public registry.  A prohibition against destruction of critical habitat under ss. 58(1) will apply 90 days after the description of the critical habitat is published in the Canada Gazette.

For critical habitat located on other federal lands, the competent minister must either make a statement on existing legal protection or make an order so that the prohibition against destruction of critical habitat applies.

If the critical habitat for a migratory bird is not within a federal protected area and is not on federal land, within the exclusive economic zone or on the continental shelf of Canada, the prohibition against destruction can only apply to those portions of the critical habitat that are habitat to which the Migratory Birds Convention Act, 1994 applies as per SARA ss. 58(5.1) and ss. 58(5.2).

For any part of critical habitat located on non-federal lands, if the competent minister forms the opinion that any portion of critical habitat is not protected by provisions in or measures under SARA or other Acts of Parliament, or the laws of the province or territory, SARA requires that the Minister recommend that the Governor in Council make an order to prohibit destruction of critical habitat. The discretion to protect critical habitat on non-federal lands that is not otherwise protected rests with the Governor in Council.

Acknowledgements

Development of this recovery strategy was coordinated by Kella Sadler and Matt Huntley (Environment and Climate Change Canada, Canadian Wildlife Service – Pacific Region (ECCC CWS-PAC)). Jennifer Heron (British Columbia Ministry of Environment (B.C. MoE)) provided supporting data and background documents. Patrick Lilley, Crispin Guppy, Connie Miller-Retzer (B.C. Ministry of Forests, Lands and Natural Resource Operations), David Trotter (B.C. Ministry of Agriculture), Jennifer Heron (B.C. MoE), Peter Fielder (B.C. MoE), Chris Pasztor (B.C. Ministry of Natural Gas Development), Kim Borg (ECCC CWS – National Capital Region), and Peter Bedrossian (Department of National Defence) provided helpful editorial advice and comment. Nick Page and Claudia Schaefer of Raincoast Applied Ecology compiled information for the first draft of this recovery strategy. Danielle Yu and Douglas Hrynyk (ECCC CWS-PAC) provided additional assistance with mapping and figure preparation.

Additions and modifications to the adopted document

The following sections have been included to address specific requirements of the federal Species at Risk Act (SARA) that are not addressed in the Recovery Plan for Dun Skipper (Euphyes vestris) in British Columbia (Part 2 of this document, referred to henceforth as "the provincial recovery plan") and/or to provide updated or additional information. 

Under SARA, there are specific requirements and processes set out regarding the protection of critical habitat. Therefore, statements in the provincial recovery plan referring to protection of survival/recovery habitat may not directly correspond to federal requirements and are not being adopted by Environment and Climate Change Canada as part of the federal recovery strategy. Recovery measures dealing with the protection of habitat are adopted; however, whether these measures will result in protection of critical habitat under SARA will be assessed following publication of the final federal recovery strategy.

Two Dun Skipper subspecies occur in Canada: a western subspecies (Euphyes vestris vestris) found only in British Columbia (B.C.), and an eastern subspecies (Euphyes vestris metacomet) found from Alberta east to Nova Scotia (Layberry et al. 1998; NatureServe 2015). Only Dun Skipper, vestris subspecies has been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). All references to "Dun Skipper" in this document refers to Dun Skipper vestris subspecies unless stated otherwise.

1 Species status information

This section replaces the "Species Status Information" (section 2) in the provincial recovery plan.

Legal Status: SARA Schedule 1 (Threatened) (2000).

Table 1. Conservation Status of Dun Skipper vestris subspecies (NatureServe 2015, B.C. Conservation Data Center 2015, B.C. Conservation Framework 2015).
Global (G) rankaNational (N) rankaSub-national (S) rankaCOSEWIC designationB.C. listbB.C. Conservation Framework
G5T4cCanada (N2); United States (N3N4)Canada:
British Columbia (S2);
United States: Washington (S3), Wyoming (SNR)
Threatened (2013)Red (2013)Highest priority: 2 under goal 2d

a Rank 1– critically imperiled; 2– imperiled; 3- vulnerable to extirpation or extinction; 4- apparently secure; 5– secure; H– possibly extirpated; NR – status not ranked

b List of ecological communities, species and subspecies considered to be extirpated, endangered or threatened (Red List), special concern (Blue List) or not at risk (Yellow List) in B.C.

c T-rank indicates the status of infraspecific taxa (i.e. the vestris subspecies).

d The three goals of the B.C. Conservation Framework are: 1. Contribute to global efforts for species and ecosystem conservation; 2. Prevent species and ecosystems from becoming at risk; 3. Maintain the diversity of native species and ecosystems

Approximately 15% of the global range of Dun Skipper vestris subspecies is estimated to be in Canada (COSEWIC 2013).

2 Species populations and distribution

This section replaces the information summary for known populationsFootnote 2 of Dun Skipper vestris subspecies in Canada (Table 1 in section 3.2 of the provincial recovery plan).

The information summary below (Table 2) describes the updated distribution of populations in Canada, all occurring in southwestern B.C. Since publication of the provincial recovery plan, two additional populations have been included from occurrences near Pemberton in 2009, at Blackwater Creek (Population 26) and Railroad Creek (Population 27) (Knopp et al. 2009). Excepting these additional populations (i.e., Populations 26 & 27), all population numbers in this section align with those provided in the provincial recovery plan. Several unverified records have also been reported (e.g., Cumberland Marsh near Comox in 2010, Rhododendron Lake near Parksville in 2013 and 2014, and many similar older records), however owing to the difficulty in accurately identifying the species from singleton/quick fly-by sightings, these have not been included in the population summary table.

Of the 27 recorded Dun Skipper populations, 19 are considered extant, 7 are considered extirpated (not observed for > 20 years, and/or suitable habitat is no longer present), and one is of unknown status. Population #11 (unknown status) has not been verified and specific date and location details are lacking.

Table 2. Summary of Dun Skipper populations in B.C. For each population (Pop.), the location, date of last observation (Last Obs.), and current status are described.
Pop.LocationLast Obs.Statuse
1Cowichan Station (Vancouver Island)1996Extirpated
2Mill Bay, Malahat Ridge (Vancouver Island)1996Extirpated
3Malahat, Colpman, and van Home Creeks; Spectacle Lake (Vancouver Island)2003 (van Home Creek)f;
1993 (Colpman Creek;
1963 (Spectacle Lake)
Extantf
4Mount Tzuhalem; Maple Bay (Vancouver Island)1994Extirpated
5Cobble Hill (Vancouver Island)1995Extirpated
6Nanaimo River (Vancouver Island)2011Extant
7Port Alberni, northeast of (Vancouver Island)2003Extant
8Mount Currie (Mainland)2001Extant
9Shawnigan Lake, west of (Vancouver Island)2003Extant
10Big Sicker Mountain; Little Sicker Mountain; Mount Prevost; Somenos Garry Oak Preserve (Vancouver Island)2003 (Big Sicker Mountain)f;
1973 (Little Sicker Mountain, Mount Prevost, Somenos Garry Oak Preserve)
Extantf
11Powell River (Sunshine Coast, mainland)UnknownUnknown (unverified)
12Koksilah River (Vancouver Island)2003Extant
13Colquitz; Francis/King Park and Thetis Lake Park (Vancouver Island)1963 (Thetis Lake Park);
1962 (Francis/King Park)
Extirpated
14Wellington (Vancouver Island)1979Extirpated
15Goldstream (Vancouver Island)1923Extirpated
16Boston Bar (lower Fraser Valley)2007Extant
17Dog Mountain (lower Fraser Valley)2010Extant
18Denman Island (northern Gulf Islands)2007Extant
19Saltspring Island; southeast (southern Gulf Islands)2009Extant
20Burns Bog (Lower Mainland)2004Extant
21Hornby Island (Northern Gulf Islands)2004Extant
22Morris Lake, west of (lower Fraser Valley)2011Extant
23Soowahlie Indian Reserve 14 (lower Fraser Valley)2004Extant
24Yale (lower Fraser Valley)2001Extant
25Lytton, south of (lower Fraser Valley)2007Extant
26Blackwater Creek (Mainland)2009Extant
27Railroad Creek (Mainland)2009Extant

e The status of Dun Skipper populations is as follows: Extant – record has been verified since 2001.

f Indicates site of last observation for populations with multiple location records; Extirpated - record before 2001 or habitat no longer present; Unknown (unverified) – Recent observation but occurrence details are lacking (i.e., presence of habitat, precise population, etc.)

3 Critical habitat

This section replaces the "Information on Habitat Needed to Meet Recovery Goal" (section 7) in the provincial recovery plan.

Section 41 (1)(c) of SARA requires that recovery strategies include an identification of the species' critical habitat, to the extent possible, as well as examples of activities that are likely to result in its destruction. The provincial recovery plan for Dun Skipper includes a description of the biophysical attributes of survival/recovery habitat. This science advice was used to inform the following critical habitat sections in this federal recovery strategy. Detailed methods and decision-making processes relating to critical habitat identification are archived in a supporting document.

Critical habitat for the Dun Skipper can only be partially identified at this time. Critical habitat cannot yet be identified for one population (#11) owing to a high level of location uncertainty and its unknown status. A schedule of studies (section 3.2) has been included to provide the information necessary to complete the identification of critical habitat for Dun Skipper. The identification of critical habitat will be updated when the information becomes available, either in a revised recovery strategy or action plan(s).

Critical habitat for Dun Skipper is identified in this document to the extent possible; as responsible jurisdictions and/or other interested parties conduct research to address the schedule of studies and/or other knowledge gapsFootnote 3 (including identification of specific host plant(s) of larval and overwintering stages, or other descriptive habitat requirements), the critical habitat methodology and identification may be modified and/or refined to reflect new knowledge.

3.1 Identification of the species' critical habitat

Geospatial location (population) of areas containing critical habitat

Critical habitat for Dun Skipper is identified for 19 known extant populations (refer to Table 2) in southwestern British Columbia (Figures 1-9):

  • Population 3: van Home Creek (Figure 1)
  • Population 6: Nanaimo River (Figure 2)
  • Population 7: northeast of Port Alberni (Figure 3)
  • Population 8: Mount Currie (Figure 4)
  • Population 9: west of Shawnigan Lake (Figure 1)
  • Population 10: Big Sicker Mountain (Figure 2)
  • Population 12: Koksilah River (Figure 1)
  • Population 16: Boston Bar (Figure 5)
  • Population 17: Dog Mountain (Figure 6)
  • Population 18: Denman Island (Figure 3)
  • Population 19: southeast Saltspring Island (Figure 7)
  • Population 20: Burns Bog (Figure 8)
  • Population 21: Hornby Island (Figure 3)
  • Population 22: west of Morris Lake (Figure 9)
  • Population 23: Soowahlie Indian Reserve 14 (Figure 9)
  • Population 24: Yale (Figure 6)
  • Population 25: south of Lytton (Figure 5)
  • Population 26: Blackwater Creek (Figure 4)
  • Population 27: Railroad Creek (Figure 4)

The areas containing critical habitat for Dun Skipper vestris subspecies are identified based on a combination of (1) all recent (<20 years old) documented occurrencesFootnote 4 from known or suspected extant populations, and (2) an estimate of the lifetime seasonal dispersal capabilities of adult Dun Skipper, applied as a 1000 m radius around each documented occurrence.

The dispersal ability of Dun Skipper vestris subspecies is not known. However, based on studies of biologically similar species, best available information indicates a dispersal estimate of approximately 1000 m. NatureServe (Schweitzer 2001) cites a default upper limit of 1000 m inferred extent buffer for grass skippersFootnote 5 when the extent is unknown. The Mardon Skipper (Polites mardon), has an apparent maximum dispersal distance of about 1.6 km (Runquist 2004), but generally moves less than 800 m annually (Potter and Fleckenstein 2001). Dakota Skipper (Hesperia dacotae) and Ottoe Skipper (H. ottoe), which share many life history characteristics with Dun Skipper, have been observed surviving for 19 days in the wild under normal conditions (Dana 1991). On average, Dakota Skippers moved 39 m/day while Ottoe Skippers moved 53 m/day (Dana 1991). In absence of specific information, a daily movement distance of 53 m/day x 19 days = 1007 m, or approximately 1 km lifetime seasonal dispersal, was considered to be an appropriate distance to use in delineating area containing critical habitat for Dun Skipper.

Biophysical attributes of critical habitat

Within the areas identified as containing critical habitat, critical habitat is identified wherever any of the following habitat types occur:

  • Open Douglas-fir (Pseudotsuga menziesii) forest; open deciduous woodlands (including Bigleaf Maple (Acer macrophyllum)); Garry Oak (Quercus garryana) and associated ecosystems
  • Open areas without developed tree or shrub layer that are natural or anthropogenic in origin, e.g., open sparsely vegetated cliffs; gently sloping hillsides, grasslands, or meadows; roadsides, ditches, utility right-of-ways
  • Permanent or seasonally wet areas (i.e., areas with wet and moist ground throughout the spring/summer) that are natural or anthropogenic in origin, e.g., wetlands; seasonally wet grasslands or meadows; areas with spring floods; natural hot springs; seeps; seasonally wet areas; stream banks; ditches; roadside banks, swamps; marshes; bogs

Within the habitat types mentioned, Dun Skipper uses host plants for larval feeding, and other plants for adult nectaring, as well as structural elements for resting and hiding from predators. Information about the identity, composition, density, and spatial relationship of larval host plant and nectar source plant species required by Dun Skipper used during different life history stages is unknown. Dun Skipper has been observed to use a variety of native and non-native flowering plants as nectar sources during the flight period (May to August, inclusive), depending on availability, including but not limited to: Dogbane (Apocynum spp.), Alfalfa (Medicago sativa)Footnote 6, Fireweed (Epilobium angustifolium), Lotus Milk-vetch (Astragalus lotiflorus), Goldenrod (Euthamia spp. and Solidago spp.), Sweet William (Dianthus barbatus)Footnote 6, various species of thistles (family Asteraceae), Self-heal (Prunella vulgaris)Footnote 6, Mint (Mentha spp.) and Oxeye Daisy (Leucanthemum vulgare)Footnote 6. Larval host plants for the eastern North American subspecies (Euphyes vestris metacomet) and Harbison's Dun Skipper (E. v. harbisoni) from southern California are known to be sedges (Carex or Cyperus species) (COSEWIC 2013; Marschalek and Deutschman 2015). It is likely that Dun Skipper in B.C. may use and/or require sedge plants and/or grasses for overwintering and larval feeding. Considering its distribution, it is likely that more than one larval host plant species is used. Based on the observations of larval silk shelters (required by Dun Skipper for pupation in spring), it would appear that as long as the leaf type is suitable, any species in the sedge (Cyperaceae) or grass families (Poaceae) may be adequate for larval development (Shepard 2000; James and Nunnallee 2011).

Biophysical attributes of critical habitat include the vegetation (composition and abundance of plant species), permanent or seasonally wet areas, and substrates that comprise the habitat types described above. The areas containing critical habitat for Dun Skipper (totaling 11184 ha) are presented in Figures 1-9. Critical habitat for Dun Skipper in Canada occurs within the shaded yellow polygons shown on each map where the criteria and methodology set out in this section are met.

Within these polygons, clearly unsuitable habitats such as: (i) areas of dense, closed, dry forest, (ii) deeper water areas (i.e., > 50 cm depth at lowest recorded watermark) beyond the range of shoreline vegetation, and (iii) existing permanent anthropogenic infrastructure (buildings) and/or running surfaces of paved roads or other artificial surfaces do not possess biophysical attributes required by Dun Skipper, and neither are they identified as critical habitat. The 1 km x 1 km UTM grid overlay shown on these figures is a standardized national grid system that highlights the general geographic area containing critical habitat, for land use planning and/or environmental assessment purposes. Detailed methods and decision-making processes relating to critical habitat identification are archived in a supporting document.

Figure 1. Critical habitat for Dun Skipper vestris subspecies at van Home Creek (Population 3; 329.6 ha), Koksilah River (Population 12; 329.6 ha), and west of Shawnigan Lake (Population 9; 329.6 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 1

Figure 1 shows critical habitat for Dun Skipper vestris subspecies at Van Home Creek, Koksilah River, and west of Shawnigan Lake B.C. The critical habitat is in accordance with the criteria and methodology set out in section 1.1 and shown by 1 km x 1 km standardized UTM grid overlay. There are 8 grid squares in each region of Koksilah River and Shawnigan Lake, and 9 grid squares in the Van Home Creek region.

Figure 2. Critical habitat for Dun Skipper vestris subspecies at Nanaimo River (Population 6; 682.0 ha) and Big Sicker Mountain (Population 10; 329.6 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 2

Figure 2 shows critical habitat for Dun Skipper vestris subspecies at Nanaimo River and Big Sicker Mountain, B.C. The critical habitat is in accordance with the criteria and methodology set out in section 1.1 and shown by 1 km x 1 km standardized UTM grid overlay. There are 14 grid squares in the Nanaimo River region and 8 in the Big Sicker region.

Figure 3.
Critical habitat for Dun Skipper vestris subspecies northeast of Port Alberni (Population 7; 434.7 ha), at Denman Island (Population 18; 739.2 ha), and at Hornby Island (Population 21; 129.1 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.Image of map (see long description below)
Long description for Figure 3

Figure 3 shows critical habitat for Dun Skipper vestris subspecies northeast of Port Alberni, Denman Island, and at Hornby Island, B.C. The critical habitat is in accordance with the criteria and methodology set out in section 1.1 and shown by 1 km x 1 km standardized UTM grid overlay. There are 9 grid squares in the Port Alberni region, 13 at Denman Island, and 5 at Hornby Island.

Figure 4. Critical habitat for Dun Skipper vestris subspecies at Mount Currie (Population 8; 329.6 ha), Blackwater Creek (Population 26; 329.6 ha), and Railroad Creek (Population 27; 329.6 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 4

Figure 4 shows critical habitat for Dun Skipper vestris subspecies at Mount Currie, Blackwater Creek, and Railroad Creek, B.C. The critical habitat is in accordance with the criteria and methodology set out in section 1.1 and shown by 1 km x 1 km standardized UTM grid overlay. There are 8 grid squares at Mount Currie and Blackwater Creek, and 9 at Railroad Creek.

Figure 5. Critical habitat for Dun Skipper vestris subspecies south of Lytton (Population 25; 724.0 ha) and at Boston Bar (Population 16; 3063.7 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 5

Figure 5 shows critical habitat for Dun Skipper vestris subspecies south of Lytton and at Boston Bar, B.C. The critical habitat is in accordance with the criteria and methodology set out in section 1.1 and shown by 1 km x 1 km standardized UTM grid overlay. There are 18 grid squares in the region of Kanaka Bar, 9 grid squares just east of Nahatlatch Lake Provincial Park, 46 grid squares in the Boothroyd region, and 9 grid squares just south of Boston Bar.

Figure 6. Critical habitat for Dun Skipper vestris subspecies at Dog Mountain (Population 17; 664.9 ha) and at Yale (Population 24; 329.6 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 6

Figure 6 shows critical habitat for Dun Skipper vestris subspecies at Dog Mountain and at Yale, B.C. The critical habitat is in accordance with the criteria and methodology set out in section 1.1 and shown by 1 km x 1 km standardized UTM grid overlay. There are 12 grid squares in the Dog Mountain area and 9 grid squares in the Yale region.

Figure 7. Critical habitat for Dun Skipper vestris subspecies at Saltspring Island (Population 19; 666.0 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 7

Figure 7 shows critical habitat for Dun Skipper vestris subspecies at Saltspring Island, B.C. The critical habitat is in accordance with the criteria and methodology set out in section 1.1 and shown by 1 km x 1 km standardized UTM grid overlay. There are 9 grid squares near Burgoyne Bay and 8 grid squares near Weston Lake.

Figure 8. Critical habitat for Dun Skipper vestris subspecies at Burns Bog (Population 20; 454.3 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 8

Figure 8 shows critical habitat for Dun Skipper vestris subspecies at Burns Bog, B.C. The critical habitat is in accordance with the criteria and methodology set out in section 1.1 and shown by 1 km x 1 km standardized UTM grid overlay. There are 10 grid squares just north of Sunshine Woods Golf Centre.

Figure 9. Critical habitat for Dun Skipper vestris subspecies west of Morris Lake (Population 22; 659.2 ha) and at Soowahlie Indian Reserve 14 (Population 23; 329.6 ha), B.C. is represented by the yellow shaded polygons (units) where the criteria and methodology set out in Section 1.1 are met. The 1 km x 1 km UTM grid overlay shown on this figure is a standardized national grid system that indicates the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 9

Figure 9 shows critical habitat for Dun Skipper vestris subspecies west of Morris Lake and at Soowahlie Indian Reserve 14, B.C. There are 2 clusters of grid squares in the Morris Lake region, one with 8 grid squares and one with 9. There are 9 more grid squares in the Soowahlie Indian Reserve 14 region.

3.2 Schedule of studies to identify critical habitat

This section replaces the "Studies needed to describe survival/recovery habitat" section (section 7.2) in the provincial recovery plan.

The following schedule of studies (Table 3) outlines the activity required to complete the identification of critical habitat for Dun Skipper vestris subspeciesFootnote 7.

Table 3. Schedule of Studies to Identify Additional Critical Habitat
Description of activityOutcome/rationaleTimeline
Conduct  targeted, comprehensive surveys in areas of suitable habitat within the proximity of the observation of Dun Skipper at population #11 to identify the population of this record and confirm the status as extant.Critical habitat could not be identified for one population owing to its "unknown" status. Without further information on the status and spatial location of this population, it is unknown whether there is sufficient critical habitat identified for Dun Skipper.2017 - 2022

3.3 Activities likely to result in the destruction of critical habitat

Understanding what constitutes destruction of critical habitat is necessary for the protection and management of critical habitat. Destruction is determined on a case by case basis. Destruction would result if part of the critical habitat were degraded, either permanently or temporarily, such that it would not serve its function when needed by the species. Destruction may result from a single or multiple activities at one point in time or from the cumulative effects of one or more activities over time. Activities described in Table 4 include those likely to cause destruction of critical habitat for Dun Skipper vestris subspecies; destructive activities are not limited to those listed.

Table 4. Activities likely to result in the destruction of critical habitat for Dun Skipper vestris subspecies. IUCN Threat numbers are in accordance with the IUCN-CMP (World Conservation Union–Conservation Measures Partnership) unified threats classification system (CMP 2010).
Description of activityDescription of effect on biophysical attribute (or other) in relation to loss of functionRelated threats and additional information
Conversion of natural landscape for human developments (e.g. housing and urban areas, commercial and industrial areas, tourism and recreation; agriculture; mining and quarrying; expansion of transportation and service corridors)Results in the direct loss of critical habitat through vegetation removal and replacement, debris deposition, and/or other related indirect effects which cause damage or destruction to biophysical attributes required by Dun Skipper. Indirect loss of critical habitat can also occur by alteration of local microsite conditions (such as light and hydrological conditions) to the extent that it is no longer suitable for Dun Skipper larval host and/or nectar source plants.

Related IUCN threats: # 1.1, 1.2, 1.3, 2.1, 3.2, 4.1, 4.2

The primary threat to Dun Skipper vestris is the cumulative loss, degradation, and fragmentation of suitable habitat. Several urban housing, commercial, and recreational facility (e.g., golf course) developments are ongoing or planned for immediate commencement. Roadside gravel extraction could occur at Population #16 (Boston Bar). Increased roads, trails and corridor developments are ongoing or proposed at several populations.

Construction and maintenance activities along transportation and utility corridors (e.g., natural gas line installment or repair, grading, ditch maintenance to remove eroded debris and re-contour ditch slopes, vegetation mowing or herbicide spraying for noxious weed control, vegetation removal to reduce wildfire concerns, and/or pesticide spraying to control invertebrate pests). This may include on-site activities, and/or drift from adjacent areas.

Results in the temporary or permanent loss of biophysical attributes that are required for Dun Skipper, including habitat required for larval host and/or nectar source plants (directly, or indirectly via decreased available moisture retention within habitats).

Efforts to control invertebrate pests or invasive plants through chemical means (pesticides or herbicides) or by physical means can result in destruction of critical habitat by degrading or removing larval host and/or nectar source plants required for survival (as a consequence of weed-pulling), or microhabitat toxicity resulting from the application of pesticides and/or herbicides.

Related IUCN threats:  #4.1, 4.2, 7.1, 7.3, 8.1

Depending on frequency and scheduling, mowing and brush-cutting may, in some circumstances, have a neutral or even beneficial effect on Dun Skipper by reducing encroachment. Thresholds are unknown, however appropriate timing (i.e., outside of flight period: May to August) and application (i.e., avoiding loss of larval host plants and substrate disturbance) are essential to avoid destruction. Herbicides are used to control roadside and right-of way vegetation at several populations. Dun Skipper is within the introduction range of European Gypsy Moth (Lymantria dispar) and spray has been applied to eradicate this species in numerous areas within the range of Dun Skipper.

Fire suppression and/or human-caused fire resulting in destruction to existing biophysical attributes of critical habitatContinued active fire suppression results in long-term loss of open habitat due to tree encroachment (succession), and alteration of plant community composition such that it no longer contains habitat types required by Dun Skipper. Conversely, where these biophysical attributes do exist, human-caused fire can result in their destruction.

Related IUCN threats: # 4.1, 4.2, 7.1, 7.3, 8.2

Fire suppression within Garry oak and associated open habitats has led to a decline in open habitats required by Dun Skipper. The threat of fire is also present, particularly within large natural tracts of land as well as areas adjacent to roadways and right-of-ways and in recreational areas where brush burning may be used as a form of fire suppression.

Deliberate introduction of alien invasive species, for example by not following provincial best management practices for clean equipment useg in transportation/utility corridor maintenance.Alien invasive species may cause destruction of habitat available to Dun Skipper by displacing required habitat attributes, as a consequence of their physical occupation of space and resources, and/or indirectly through effects on associated vegetation.

Related IUCN threat # 8.1

Many of the locations where Dun Skipper has been recorded have become degraded and/or dominated by introduced species such as agronomic grasses and weedy forbs, as well as Scotch Broom (Cytisus scoparius), and Himalayan Blackberry (Rubus armeniacus).

g see "Best Management Practices for Invasive Plants in Parks and Protected Areas of British Columbia (PDF: 15.4 Mb)"

4 Measuring progress

This section replaces the "Section 8: Measuring Progress" section in the provincial recovery plan.

Priority actions for Dun Skipper vestris subspecies are included in Table 4 of the provincial recovery plan. The performance indicators presented below provide a way to define and measure progress toward achieving the population and distribution objectives:

  • The distribution and abundance of all known extant Dun Skipper vestris subspecies populations (including any newly identified populations) have been maintained, i.e., population size and extent of occurrence or area of occupancy at each site is stable and/or naturally increasing.

5 Statement on action plans

One or more action plans for Dun Skipper will be posted on the Species at Risk Public Registry by 2022.

6 Effects on the environment and other species

A strategic environmental assessment (SEA) is conducted on all SARA recovery planning documents, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals. The purpose of a SEA is to incorporate environmental considerations into the development of public policies, plans, and program proposals to support environmentally sound decision-making and to evaluate whether the outcomes of a recovery planning document could affect any component of the environment or any of the Federal Sustainable Development Strategy's (FSDS) goals and targets.

Recovery planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that strategies may also inadvertently lead to environmental effects beyond the intended benefits. The planning process based on national guidelines directly incorporates consideration of all environmental effects, with a particular focus on possible impacts upon non-target species or habitats. The results of the SEA are incorporated directly into the strategy itself, but are also summarized below in this statement.

The provincial recovery plan for Dun Skipper contains a section describing the effects of recovery activities on other species (i.e., Section 9). Environment and Climate Change Canada adopts this section of the provincial recovery plan as the statement on effects of recovery activities on the environment and other species. The distribution of Dun Skipper overlaps with that of several other federally-listed species at risk in British Columbia that occur in the coastal lowlands of southeastern Vancouver Island, the Gulf Islands, and the lower Fraser Valley. Recovery planning activities for Dun Skipper will be implemented with consideration for all co-occurring species at risk, to avoid or minimize negative impacts to these species or their habitats. Some management actions for Dun Skipper (e.g., inventory and monitoring, threat mitigation, habitat conservation, education, and research) may promote the conservation of other species at risk that overlap in distribution and rely on similar habitat attributes.

7 References

B.C. Conservation Data Centre. 2015. B.C. Species and Ecosystems Explorer. B.C. Ministry of Environment, Victoria, B.C. [Accessed February, 2015].

B.C. Conservation Framework. 2015. Conservation Framework Summary: Apodemia mormo. B.C. Ministry of the Environment. [Accessed May, 2015]

COSEWIC. 2013. COSEWIC assessment and status report on the Dun Skipper (vestris subspecies), Euphyes vestris vestris in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xi + 69 pp. Species at Risk Public Registry

CMP (Conservation Measures Partnership). 2010. Threats Taxonomy. Available: http://www.conservationmeasures.org/initiatives/threats-actions-taxonomies/threats-taxonomy.

Dana, R.P. 1991. Conservation management of the Prairie Skippers Hesperia dacotae and Hesperia ottoe: basic biology and threat of mortality during prescribed burning in spring. Minnesota Agricultural Experiment Station Bulletin 594 – 1991 (AD-SB-5511-S). University of Minnesota, St. Paul. 63pp.

James, D. and D. Nunnallee. Life histories of Cascadia butterflies. Oregon State University Press, Corvallis, OR. 447pp.

Knopp, D., L. Larkin, and J. Heron. 2009. Surveys for Dun Skipper (Euphyes vestris) in the Lower Fraser Valley, B.C., B.C. Min. Environ., Ecosystems Branch, Wildlife Science Section, Vancouver, BC. 53 pp.

Layberry, R.A., P.W. Hall, J.D. Lafontaine (plates by J.T. Fowler). 1998. The butterflies of Canada. Univ. Toronto Press, Toronto, Buffalo and London. 280 pp.

Marschalek D.A. and D.H. Deutschman. 2015. Initial investigation of critical biological uncertainties for Harbison's dun skipper (Euphyes vestris harbisoni) on conserved lands in San Diego County. 23 pages + app.

NatureServe. 2015. NatureServe Explorer: an online encyclopedia of life [web application]. Version 7.1. Arlington, V.A. [Accessed July, 2015].

Potter, A. and J. Fleckenstein. 2001. Southern Cascade surveys for the Mardon skipper. Summary year 2000. Final report to the U.S. Fish and Wildlife Service, Western Washington Office, Lacey, WA. 11 pp.

Runquist, E. 2004. Workshop on the ecology and status of the Mardon skipper (Polites mardon): An unusual Pacific Northwest butterfly. Ashland, OR.

Schweitzer, D.F. 2001. Population/occurrence delineation – AMBLYSCIRTES species. Section in NatureServe. 2015. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. [Accessed July, 2015].

Shepard, J.H. 2000. Status report on the Dun Skipper, Euphyes vestris vestris (Boisduval, 1852) (Lepidoptera: Hesperiidae) in Canada. Report prepared for Committee on the Status of Endangered Wildlife in Canada. 7 pp.

Footnotes

Footnote 1

These federally protected areas are:  a national park of Canada named and described in Schedule 1 to the Canada National Parks Act, The Rouge National Park established by the Rouge National Urban Park Act, a marine protected area under the Oceans Act, a migratory bird sanctuary under the Migratory Bird Convention Act, 1994 or a national wildlife area under the Canada Wildlife Act see ss. 58(2) of SARA.

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Footnote 2

Populations are based on the biological parameters of the butterfly (e.g. dispersal distance and habitat connectivity between known occurrences, and whether the individuals mix between). Population designations in this federal addition are based on those provided in the provincial recovery plan.

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Footnote 3

Refer to priority actions outlined in the recovery planning table (Table 4) of the provincial recovery plan.

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Footnote 4

An occurrence is defined as the occupied habitat patch at which an individual(s) was observed. Occurrences may consist of multiple individuals over multiple years from a spatially distinct site that were obtained during surveys or research projects. Occurrence areas includethe associated potential error from geographic positioning system (GPS) units (uncertainty may range up to 25 m depending on the GPS unit accuracy).

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Footnote 5

Dun Skipper belongs to the Lepidoptera sub-family of grass skippers (Hesperiinae).

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Footnote 6

Introduced (non-native) to B.C.

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Footnote 7

For further research to address knowledge gaps, refer to priority actions outlined in the recovery planning table (Table 4) of the provincial recovery plan.

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