Recovery Strategy for the Behr’s Hairstreak (Satyrium behrii) in Canada - 2016
- Part 1 - Federal Addition to the "Recovery Strategy for Behr's Hairstreak (Satyrium behrii) in British Columbia", prepared by Environment and Climate Change Canada.
- Appendix 1. Maps of Critical Habitat for Behr's Hairstreak in Canada
- Part 2 – "Recovery Strategy for Behr’s Hairstreak (Satyrium behrii) in British Columbia", prepared by the Southern Interior Invertebrates Recovery Team for the British Columbia Ministry of Environment.
Part 1 - Federal Addition to the "Recovery Strategy for Behr's Hairstreak (Satyrium behrii) in British Columbia", prepared by Environment and Climate Change Canada.
Environment and Climate Change Canada. 2016. Recovery Strategy for the Behr's Hairstreak (Satyrium behrii) in Canada. Species at Risk Act Recovery Strategy Series. Environment and Climate Change Canada, Ottawa. 2 parts, 28 pp. + 16 pp.
For copies of the recovery strategy, or for additional information on species at risk, including the Committee of the Status of Wildlife in Canada (COSEWIC) Status Reports, residence descriptions, action plans, and other related recovery documents, please visit the Species at Risk (SAR) Public Registry.
Cover illustration: © Neil K. Dawe
Également disponible en français sous le titre
« Programme de rétablissement du porte-queue de Behr (Satyrium behrii) au Canada »
Content (excluding the illustrations) may be used without permission, with appropriate credit to the source.
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 the Environment and Climate Change is the competent minister for the recovery of the Behr's Hairstreak and has prepared the federal component of this recovery strategy (Part 1), as per section 37 of SARA. It has been prepared in cooperation with the province of British Columbia. SARA section 44 allows the Minister to adopt all or part of an existing plan for the 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 strategy for the Behr's Hairstreak (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 Behr's Hairstreak 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, there may be future regulatory implications, depending on where the critical habitat is identified. SARA requires that critical habitat identified within a national park named and described in Schedule 1 to the Canada National Parks Act, the Rouge National Urban Park established by the Rouge National Urban Park Act, a marine protected area under the Oceans Act, a migratory bird sanctuary under the Migratory Birds Convention Act, 1994 or a national wildlife area under the Canada Wildlife Act be described in the Canada Gazette, after which prohibitions against its destruction will apply. 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. 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.
Many people are to be acknowledged for their involvement in the preparation of this federal recovery strategy addition. This document was prepared by Kella Sadler (Environment Canada and Climate Change, Canadian Wildlife Service (ECCC CWS) - Pacific and Yukon Region (PYR)) with the input of Dan Shervill (ECCC CWS-PYR) and Laura Parkinson. Substantial input and/or collaborative support was provided by Leah Westereng, Jennifer Heron, Bryn White, Orville Dyer, Mark Weston, Kirk Safford, and Jim Mottishaw (Government of British Columbia, Dennis St. John (Private Entomologist), Sylvie Desjardins (UBC Kelowna), Geoff Scudder (UBC), and Dennis Knopp (Private Consultant, Sardis). Richard Post, Amos Chow, Clare O'Brien and Sean Butler provided 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 Strategy for the Behr's Hairstreak (Satyrium behrii) in British Columbia" (Part 2 of this document, referred to henceforth as "the provincial recovery strategy") and 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 strategy referring to protection of survival/recovery habitat may not directly correspond to federal requirements. 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 federal recovery strategy.
The provincial recovery strategy for Behr’s Hairstreak contains a short statement on socio-economic considerations. As a socio-economic analysis is not required under Section 41(1) of SARA, the “Socio-economic Considerations” section of the provincial recovery strategy is not considered part of the federal recovery strategy for this species.
1. COSEWIC Species Assessment Information
This section replaces the "Species Assessment Information from COSEWIC" section in the provincial recovery strategy.
Behr's Hairstreak was first designated as "Threatened" by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) in 2000:
Species Assessment Information from COSEWIC (2000)
Date of Assessment: November 2000
Common Name (population): Behr's Hairstreak
Scientific Name: Satyrium behrii columbia
COSEWIC Status: Threatened
Reason for Designation: This species occurs as scattered populations throughout its historic range and uses antelope-brush (Purshia tridentata) as its host plant. Significant portions of the Purshia habitat have already been lost and the remaining habitat is fragmented. Further habitat losses are expected.
Canadian Occurrence: British Columbia
COSEWIC Status history: Designated as Threatened by COSEWIC in November 2000
Behr's Hairstreak was then re-assessed as "Endangered" (i.e., a higher risk category) by COSEWIC in 2012:
Species Assessment Information from COSEWIC (2012)
Date of Assessment: May 2012
Common Name (population): Behr's Hairstreak
Scientific Name: Satyrium behrii
COSEWIC Status: Endangered
Reason for Designation: This small butterfly is restricted to antelope-brush habitat in British Columbia, a habitat that has decreased considerably in extent in the past century and remains under threat due to land use change (conversion to viticulture, residential and commercial development) and the impact of fire. It rarely disperses much more than 120 m and persists in small, isolated fragments of habitat, which continue to decline in area and quality. Large annual fluctuations in population size, as documented for the largest Canadian population, increase the species' vulnerability and call into question its long term viability.
Canadian Occurrence: British Columbia
COSEWIC Status history: Designated as Threatened by COSEWIC in November 2000. Status re-examined and designated Endangered in May 2012.
2. Species Status Information
Legal Status: SARA Schedule 1 (Threatened) (2003).
(G) RankNote a of Table 1
|National (N) RankNote a of Table 1||Sub-national (S) RankNote a of Table 1||COSEWICDesignation||B.C.List||B.C.Conservation Framework|
United States (N5)
|Canada: British Columbia (S1);|
Arizona (SNR), California (SNR), Colorado (S5), Idaho (SNR), Nevada (SNR), New Mexico (SNR), Oklahoma (S3?), Oregon (SNR), Texas (SNR), Utah (SNR), Washington (S5), Wyoming (SNR)
|Red List (Extirpated, Endangered, or Threatened||Highest priority : 1,|
under Goal 3Note b of Table 1
Notes of Table 1
- Note a of Table 1
Rank 1 - Critically Imperiled; 2 - Imperiled; 3 - vulnerable to extirpation or extinction; - apparently secure; – secure; – possibly extirpated; NR – status not ranked
- Note b of Table 1
The three goals of the BC 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
It is estimated that the percent of the global range of this species in Canada is less than 1%.
3. Recovery Feasibility
This section replaces the "Recovery Feasibility" section in the provincial recovery strategy.
Based on the following four criteria that Environment and Climate Change Canada uses to establish recovery feasibility, recovery of the Behr’s Hairstreak has been deemed feasible.
- 1) Individuals of the wildlife species that are capable of reproduction are available now or in the foreseeable future, to sustain the population or improve its abundance.
- Yes. There are individuals capable of reproduction available now to sustain the population and/or improve its abundance, present at multiple sites in the South Okanagan Valley. There are, however, knowledge gaps concerning population size, structure, and dispersal abilities at each site.
- 2) Sufficient suitable habitat is available to support the species or could it be made available through habitat management or restoration.
- Yes. There is sufficient suitable habitat available to support the species. Behr's Hairstreak occurs in Antelope-brush (Purshia tridentata) grasslands in the south Okanagan Valley, primarily in the Antelope-brush/Needle-and-thread Grass plant community.
- 3) The primary threats to the species or its habitat (including threats outside of Canada) can be avoided or mitigated.
- Yes. The primary threats can be mitigated through habitat conservation measures and management of Antelope-brush habitat for the conservation of Behr's Hairstreak (including education on butterfly host plants, changes to livestock grazing regimes when deemed necessary, and introduced species control). Ensuring the connectivity and integrity of Antelope-brush grasslands is important to promote the long-term persistence of Behr's Hairstreak at each site.
- 4) Recovery techniques exist to achieve the population and distribution objectives, or can be expected to be developed within a reasonable timeframe.
- Yes. Recovery techniques focus on mitigating primary threats (i.e., habitat conservation and management, as described above). Conducting further research to address knowledge gaps regarding the life history and habitat requirements of Behr's Hairstreak will facilitate prioritization of habitat for protection.
4. Population and Distribution Objective
This section replaces the "Recovery Goal" and "Rationale for Recovery Goal and Objectives" sections in the provincial recovery strategy.
Environment and Climate Change Canada has determined the Population and Distribution Objective for Behr's Hairstreak to be:
To ensure the persistence of Behr's Hairstreak at all known extant sites Footnote 1 (and any new sites) within the species' range in Canada.
Occurrence information for Behr's Hairstreak shows it is extant at seven known sites in Canada. There is one additional historical record at Penticton, British Columbia (year of observation, specific location, and current status unknown). The British Columbia Conservation Data Centre and NatureServe databases define "extant" as all observations made within the last 20 years, provided the habitat has not been substantially altered or degraded. Population numbers, including abundance trends, are unknown. Although preliminary population viability analyses have been completed (J. Heron, pers. comm. 2012), there is insufficient information to determine minimum population viability. Likewise, dispersal and re-colonization capabilities of Behr's Hairstreak are unknown, and detailed habitat and life history requirements are unclear. This species reaches the northern extent of its range in the south Okanagan Valley. There is no information to indicate that the species was previously more widespread, therefore an objective to actively increase the number of populations, which may allow for down-listing of the species, is not appropriate at this time. However, if additional naturally occurring populations are discovered, their persistence should also be ensured. Future population and distribution data may indicate that deliberate attempts to increase abundance would be warranted at one or more sites (for example, where either or both of abundance and/or species' range shows a documented decline).
5. Broad Strategies and General Approaches to Meet Objectives: Recovery Planning Table
The approaches listed in the recovery planning table in the provincial recovery strategy Table 1 include specific steps towards addressing habitat protection, habitat management, inventory and monitoring, and research. In reference to these approaches, the points below amend this table to include additional details on information considered necessary to address knowledge gaps, for the purpose of meeting recovery objectives identified in this federal recovery strategy:
- In areas where vegetation surveys have not yet been completed, ground-truth areas delineated as "suitable habitat" to confirm whether or not biophysical attributes necessary to support Behr's Hairstreak are present, and refine Terrestrial Ecosystem Mapping (TEM) classification type used to indicate "suitable habitat" so that representation of habitat quality for Behr's Hairstreak is most optimal.
- Research the importance of topographical heterogeneity at the site scale as a component of habitat capable of supporting Behr's Hairstreak.
- Identify shelter resources necessary to support Behr's Hairstreak at all stages in its life-cycle.
- Identify movement capabilities and use of corridors for dispersal among sites, as components of sustaining connectivity, and genetic viability of Behr's Hairstreak in Canada.
- Research the relationship between high and low elevation sites, i.e., investigate the potential for high elevation sites to act as sources for low-elevation sites, and characterize movement activities of Behr's Hairstreak across elevation gradients.
6. Critical Habitat
6.1 Identification of the Species' Critical Habitat
This section replaces the "Critical Habitat" section in the provincial recovery strategy.
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 2008 provincial recovery strategy for Behr's Hairstreak does not include an identification of critical habitat, nor is it required in the provincial process. Critical habitat for Behr's Hairstreak is identified in this document to the extent possible; more precise boundaries may be mapped, and additional critical habitat may be added in the future if additional research supports the inclusion of areas beyond those currently identified. Primary considerations in the identification of critical habitat include the amount, quality, and locations of habitat needed to achieve the population and distribution objectives.
Critical habitat for Behr's Hairstreak is identified at seven sites in British Columbia:
- Kaleden (Figure A1): corresponds with BC CDC EO #11
- Okanagan Falls (Figure A2), Vaseux Lake and McIntyre Bluff (Figure A3): corresponds with BC CDC EO #5
- West of Oliver (Fairview) (Figure A4): corresponds with BC CDC EO #7
- East of Oliver (Figure A5): corresponds with BC CDC EO #15
- South of Oliver (Figure A6): corresponds with BC CDC EO #13
- Osoyoos (Figure A7): corresponds with BC CDC EO #10
- East of Osoyoos (Figure A8): corresponds with BC CDC EO #8
Critical habitat is only partially identified at four of the seven sites: Kaleden, Vaseux Lake and McIntyre Bluff, East of Oliver, and South of Oliver. Environment and Climate Change Canada will work with the applicable organizations to complete the identification of critical habitat at these four sites, as outlined in the schedule of studies (Section 6.2).
The areas containing critical habitat for Behr's Hairstreak are identified based on a combination of (1) all documented occurrences Footnote2 (including data sets from the BC CDC, the recovery team and the Canadian Wildlife Service (CWS) collected between 2001 and 2013), (2) an estimate of the seasonal dispersal capabilities of adult Behr's Hairstreak butterflies, applied as a 600 m radius Footnote3 around each documented occurrence, and (3) selection of all suitable habitat within this occurrence radius. Plant communities containing >10% cover of Antelope-brush (Purshia tridentata) were selected as suitable habitat for Behr's Hairstreak (Iverson and Haney 2010), using Terrestrial Ecosystem Mapping (TEM). Ecosystem mapping units associated with individual occurrence records were considered inherently indicative of use by Behr's Hairstreak, and therefore included by default (i.e., regardless of proportion of Antelope-brush).
The biophysical attributes as detailed below summarize known essential elements for Behr's Hairstreak within the areas identified as containing critical habitat. These biophysical attributes are consistent with the habitat attributes outlined in the provincial recovery strategy, the COSEWIC status report (COSEWIC 2006), and other sources (Knopp et al. 2009; James and Nunnallee 2011). These attributes include: larval host plants, nectar host plants, and other structural elements essential for life cycle completion. Detailed information about the composition and spatial relationship of individual biophysical attributes required by Behr's Hairstreak at particular locations, and the relative amount, condition, and density of individual biophysical attributes within areas identified as containing critical habitat are currently unknown. The biophysical attributes described are identified as critical habitat wherever they occur within the area identified as containing critical habitat.
Larval Host Plants
Behr's Hairstreak uses Antelope-brush year-round, i.e., for completion of all life history stages. Antelope-brush is the only known larval host plant for Behr's Hairstreak in Canada. Inventory data and observations suggest that Behr's Hairstreak may prefer or require Antelope-brush plants 30 years or older, and/or of minimum size requirements (S. Desjardins, pers. comm. 2012; D. St. John, pers. comm. 2012). Adult butterflies lay their eggs singly on the leaves and branches of the Antelope-brush in the summer, and larvae emerge the following spring; not all plants are used every year (COSEWIC 2012). Behr's Hairstreak larvae have been observed pupating in cover adjacent to larval host plants in United States populations (James and Nunnallee 2011). Although the movement capabilities and/or patterns of Behr's Hairstreak larvae are not known, it is considered reasonable that they would not move farther than 5 m away from larval host plantsFootnote 4. As such, all Antelope-brush plants, and the soils/litter occurring within 5 m of these plants, is considered essential to Behr's Hairstreak.
Nectar Host Plants
During the flight period (typically late May to late July), Behr's Hairstreak uses one or more species as nectar host plants (proportion and availability varies by site). Known nectar host plants include: Common Yarrow (Achillea millefolium), Smooth Sumac (Rhus glabra), Grey Horsebrush (Tetradymia canescens), Buckwheat (Eriogonum sp.), Creambush Oceanspray (Holodiscus discolor), Tall Baby's-Breath (Gypsophila paniculata), Sweet-Clover (Melilotus sp.) and Fleabane (Erigeron sp.). It is suggested that Yarrow is the most important nectar source as it blooms throughout the flight period and is common and widespread (St. John and Bunge, 2003). Although Tall Baby's-Breath and Sweet-Clover are exotic plants in BC, these plants are already widespread and established (E-Flora, BC 2012) and may contribute to the habitat requirements of Behr's Hairstreak at some sites.
During the flight period, various plants and other features are used by adult Behr's Hairstreak as structural elements for perching and mating, and potentially also for roosting and/or shelter (from exposure, and also predators – including camouflage). Wherever they exist at individual locations, the following features are considered important biophysical attributes of critical habitat: Antelope-brush plants, mature Ponderosa Pine (Pinus ponderosa) trees and/or other mature trees scattered within Antelope-brush grasslands, and standing water and any associated peripheral wetted areas. Mature trees can provide shelter from weather, temperature extremes and predators, and nocturnal roosting sites for adult butterflies, and may also facilitate movements within and between habitat patches (Thomas et al., 2011). The presence of water sources may provide important moisture and/or mineral resources for Behr's Hairstreak, and help ensure the continued presence of host plants, particularly in dry years (J. Heron, pers. comm. 2012, St. John and Desjardins 2003). Water-related elements identified as critical habitat include: puddles and/or other forms of standing water and the wetted areas around them, as well as the sources which may produce them (e.g., soil moisture, ephemeral wetlands, non- fish-bearing wetlands, creeks, streams, springs) and/or features where water may pool or form puddles (e.g., depressions, draws, gullies).
The areas containing critical habitat for Behr's Hairstreak are presented in Appendix 1 (Figures A1-A8). Critical habitat for Behr's Hairstreak in Canada occurs within the detailed yellow polygons (critical habitat units) shown on each map where the occurrence radius and habitat type criteria (i.e., TEM habitat mapping) described in this section are met, and where any of the known biophysical attributes exist. Unsuitable habitats such as forested areas without an Antelope-brush component, lakes (below lowest documented water line), anthropogenic features (including active trails, roads, and existing infrastructure such as buildings) do not possess the attributes required by Behr's Hairstreak and they are not 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.
Dispersal and/or movement corridor habitat is that which is required for adult butterflies to move among sites, sub-sites or to unoccupied habitat. Connective habitat is important to prevent further fragmentation and isolation Behr's Hairstreak sites, as this butterfly will not disperse across unsuitable habitat. This species is thought to form a meta-population among Antelope-brush patches (COSEWIC, 2012) and connectivity between sites and sub-sites as facilitated by movement and/or dispersal corridors is thought to be an important factor needed to meet the population and distribution objective (S. Desjardins, pers. comm., 2012). It is recognized that the critical habitat identified above is insufficient to achieve the population and distribution objectives for Behr's Hairstreak because information that would allow for the identification of dispersal and/or movement corridors required by the species is not available at this time and further work is required to complete the identification of critical habitat at Kaleden, Vaseux Lake and McIntyre Bluff, East of Oliver, and South of Oliver sites.
The schedule of studies (Section 6.2) outlines the activities required to identify additional critical habitat necessary to support these objectives.
6.2 Schedule of Studies to Identify Critical Habitat
This section replaces the "Recommended schedule of studies to identify critical habitat" section in the provincial recovery strategy.
The following schedule of studies (Table 2) outlines the activities required to complete the identification of Behr's Hairstreak in Canada.
|Description of Activity||Outcome/Rationale||Timeline|
|Work cooperatively with applicable organizations to complete the identification of critical habitat for Behr's Hairstreak occurring at four sites: (1) Kaleden, (2) Vaseux Lake and McIntyre Bluff, (3) East of Oliver, and (4) South of Oliver, BC||This activity is required such that sufficient critical habitat is identified to meet the population and distribution objectives.||2016 - 2021|
|Determine movement activities and capabilities and dispersal requirements for Behr's Hairstreak||Movement /dispersal corridors will be included as a component of critical habitat identification, to support all extant sites of Behr's Hairstreak in Canada.||2016 - 2021|
6.3 Examples of Activities Likely to Result in 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 3 include those likely to cause destruction of critical habitat for Behr's Hairstreak; destructive activities are not limited to those listed.
|Description of Activity||Description of effect (biophysical attribute or other)||Details and relationship to identified threats|
|Conversion of natural landscape (within the areas identified as containing critical habitat) for residential, commercial, industrial, recreational, and agricultural development.||Results in the direct loss of critical habitat through vegetation removal and replacement, debris deposition, soil disturbance and compaction, and/or related indirect effects which cause damage or destruction to biophysical attributes required by Behr's Hairstreak.||The primary threat to Behr's Hairstreak is identified as habitat loss, degradation, and fragmentation of Antelope-brush plant communities. This threat is severe, widespread, and continuous.|
|Fire management strategies that result in long-term fire suppression in Antelope-brush ecosystems, and/or human-caused fire resulting in destruction to existing biophysical attributes of critical habitat.||Continued active fire suppression results in long-term loss of Antelope-brush and associated grassland habitat due to tree encroachment, and alteration of plant community composition such that it no longer contains biophysical attributes required by Behr's Hairstreak. Conversely, where these biophysical attributes do exist, deliberate or accidental human-caused fire can result in their destruction.||Fire suppression by wildfire protection programs is an ecosystem-level threat to the persistence of Antelope-brush and associated grassland habitats in B.C. Where biophysical attributes required by Behr's Hairstreak do occur, local destruction by fire is a potential threat at all sites in Canada.|
|Grazing practices at any time of year that result in the damage or destruction of larval host plants; grazing practices in the non-dormant phase (March-September inclusive) that results in the destruction of nectar host plants and/or other structural elements identified as essential to the Behr's Hairstreak; grazing practices in the dormant phase (October-February inclusive) that results in compaction or removal of soils associated with larval host plants (within 5 m), permanent net loss of nectar host plants or structural elements, and/or creation of new exposed/disturbed trails or clearings.||Livestock use results in disturbance, removal, and/or compaction of vegetation and ground layer (via grazing or trampling), causing the loss of larval and nectar host plants, essential structural elements (e.g., adult perching plants) and damage to litter required by Behr's Hairstreak eggs and larvae. New disturbance can facilitate establishment of alien invasive species.||The primary threat to Behr's Hairstreak is identified as habitat loss, degradation, and fragmentation of Antelope-brush plant communities. This threat is severe, widespread, and continuous.|
|Any motorized recreational activities (e.g., ATVs or other vehicles) occurring outside of existing roads or trails, at any time and in all seasons; non-motorized recreational activities (e.g., foot traffic, mountain biking, and horse-back riding) occurring during the non-dormant phase (March-September inclusive) to the extent that larval host plants are damaged or destroyed, or to the extent that nectar host plants and/or other structural elements identified as essential to Behr's Hairstreak are destroyed; non-motorized recreational activities during the dormant period (October-February inclusive) that results in the damage or destruction of larval host plants and/or compaction or removal of associated soils (within 5 m); non-motorized recreational activities at any time of year that (individually, and/or cumulatively) results in the permanent net loss of nectar host plants, structural elements, and/or creation of new roads, trails or clearings.||Results in disturbance of local biophysical conditions, including direct physical damage to or loss of biophysical attributes required by Behr's Hairstreak. Activities may cause vegetation removal (impacting the availability of egg, larval and nectar host plants) and cause trampling or removal of soil and litter which may be required by Behr's Hairstreak larvae and pupae. New disturbance can facilitate establishment of alien invasive species.||The primary threat to Behr's Hairstreak is identified as habitat loss, degradation, and fragmentation of antelope-brush plant communities. This threat is severe, widespread, and continuous.|
|Introduction of alien invasive Footnote5 species||Alien invasive species may cause destruction of habitat available to Behr's Hairstreak by making required biophysical attributes of critical habitat (larval host plants and nectar host plants, and/or required structural elements) functionally unavailable to Behr's Hairstreak, as a consequence of their physical occupation of space and resources.||Some alien invasive grasses may be deliberately introduced for range purposes.|
|Activities related to the control of invertebrate pests and/or invasive plant species (mechanical or chemical) that are not in accordance with provincial best management practices, where available. This may include on-site activities, and/or pesticide/ herbicide drift from adjacent agricultural areas.||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 biophysical attributes required for survival (as a consequence of weed-pulling), or microhabitat toxicity resulting from the application of pesticides and/or herbicides.||The primary threat to Behr's Hairstreak is identified as habitat loss, degradation, and fragmentation of antelope-brush plant communities. This threat is severe, widespread, and continuous.|
The primary activity likely to result in the destruction of Behr's Hairstreak critical habitat is considered to be habitat loss by conversion of natural areas for residential, commercial, agricultural and industrial development. There has been a significant decline in the amount and quality of Antelope-brush/Needle-and-thread Grass habitat in the South Okanagan Valley since 1800; as a result, habitats which may support Behr's Hairstreak have become smaller and more fragmented within their historic range in B.C. Development pressure on Antelope-brush habitats in the South Okanagan valley is ongoing (Iverson 2010). Critical habitat may be further damaged by recreation activities that results in expansion of existing roads or trails, and/or creation of new roads, trails, or clearings within areas identified as containing critical habitat. Activities associated with the regular functioning and maintenance of existing roads or trails in these areas are not considered likely to result in the destruction of critical habitat.
In many areas where Behr's Hairstreak occurs, the land management plan and expectation is to suppress fire, which can contribute to the loss of critical habitat. Slow natural succession of pines and other native trees into open areas is ongoing due to long-term fire suppression. In the absence of regularly occurring fires, the size and extent of ecological communities (and associated biophysical attributes) required by Behr's Hairstreak has likely been reduced by tree encroachment at some locations, owing to shading and competition. Conversely, human-caused fires in areas where critical habitat for Behr's Hairstreak is present may result in local destruction of necessary biophysical attributes. Habitat fragmentation and land use have altered natural fire regimes and patterns in Antelope-brush and grassland communities of the south interior of BC. It is estimated that at least half of fires in the Okanagan valley are human-caused (e.g. 56% of fires in the Okanagan fire Zone from 2004-2013 were human-caused; at lower elevations in the Okanagan Valley as much as 80% human-caused) (J. Mottishaw pers. comm. 2014). Further, invasive plants may out-compete native nectar plants post-fire and result in long-term reduction in habitat suitability, unless there is successful deliberate seeding of native species. Therefore in this portion of its range, human-caused wildfire may be more likely to result in critical habitat destruction than fire suppression, depending on historical fire regimes, current land use pressures, local vegetation community characteristics, and the intensity of fire (M. Weston, pers. comm. 2013). Prescribed burning to achieve general thinning or fuel removal at sites (e.g., for maintenance of grassland and/or open forest ecosystems) must take into account the potential negative consequences of fire to Behr's Hairstreak, where semi-isolated populations and/or local biophysical attributes required by the species could be easily and/or irreparably devastated (D. St. John, pers. comm. 2014).
Cattle are present in all of the areas where Behr's Hairstreak has been found in BC. Inappropriate grazing practices resulting in deterioration of grassland (ecosystem) health (such as loss of composition, structure, site stability, etc.) are identified as an activity likely to impact or destroy critical habitat. It is unknown to what level actual stocking rates (and yearly implementation of rates), timing of use, length of use, will affect or impact habitat to the extent that critical habitat is lost. However, it is intuitive that inappropriate use of range with intensive grazing over long periods of time will impact the biophysical attributes necessary for Behr's Hairstreak. It is possible that some level of grazing may not be detrimental to Behr's Hairstreak at some sites, e.g., where the occurrence, proportion, and abundance of larval and nectar host plants, and required structural elements are demonstrably maintained or increased under existing levels of livestock activity. Additional research is required to determine the grazing practices and/or threshold level(s) of grazing intensity that are consistent with ensuring the long-term persistence of biophysical attributes necessary for Behr's Hairstreak.
7. Statement on Action Plans
One or more action plans will be posted on the Species at Risk Public Registry by 2021.
8. 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 Antelope-brush/Needle-and-thread Grass plant community is a rare ecosystem in British Columbia (red-listed) and is globally ranked G2 or imperiled (BC Conservation Data Centre 2012). This rare plant community supports one of the highest densities of species at risk of any ecosystem in British Columbia (Iverson 2010); in addition to Behr's Hairstreak these habitats support at least 88 provincially-listed and at least 17 federally-listed species at risk (note some species of federal conservation concern are also provincially listed). Federally listed species at risk that may overlap with Behr's Hairstreak habitat include (but are not limited to): Pallid Bat (Antrozous pallidus), Mormon Metalmark – Southern Mountain Population (Apodemia mormo), Western Rattlesnake (Crotalus oreganus), Western Yellow-bellied Racer (Coluber constrictor), Great Basin Gophersnake (Pituophis catenifer deserticola), Tiger Salamander (Ambystoma mavortium), Great Basin Spadefoot (Spea intermontana), Wallis' Dark Saltflat Tiger Beetle (Cicindela parowana wallisi), Nuttall's Cottontail nuttallii subspecies (Sylvilagus nuttallii nuttallii), Lewis's Woodpecker (Melanerpes lewis), Short-rayed Alkali Aster (Symphyotrichum frondosum),Grand Coulee Owl-clover (Orthocarpus barbatus), Branched Phacelia (Phacelia ramosissima), Scarlet Ammannia (Ammannia robusta), Toothcup (Rotala ramosior), Small-flowered Lipocarpha (Lipocarpha micrantha), and Columbian Carpet Moss (Bryoerythrophyllum columbianum).
The recommended habitat conservation will indirectly benefit other species at risk in the area; increased public education and awareness may limit harmful recreational activities at these sites, and conservation actions to restore and protect grasslands ecosystems for Behr's Hairstreak are likely beneficial to all species that rely on these threatened ecosystems. Likewise, conservation actions underway or proposed to protect the other species at risk are likely beneficial to Behr's Hairstreak – a multi-species approach to conservation planning is recommended. In acknowledgement of the high potential for shared habitat among local species at risk, large-scale management actions, such as invasive species removal or the use of herbicides or pesticides, should be planned and implemented carefully. All on-site activities (surveys, research, and management), to aid recovery may pose a threat to co-occurring species (e.g., via trampling, increased herbivory via incidental creation of trails, or inadvertent dispersal of alien species during disposal), unless care is taken to avoid damage.
- Thomas, J.A., Simcox, D.J. and T. Hovestadt. 2011. Evidence based conservation of butterflies. Journal of Insect Conservation. 15: 241-258.
- Footnote 1
For the facility of description, sites are named after and based on the general geographical area in which Behr's Hairstreak is known to occur. Sites are defined to match the element occurrences (EOs) (NatureServe 2002) for Behr's Hairstreak determined by the B.C. Conservation Data Centre as closely as possible.
- Footnote 2
BC CDC occurrence records and/or any other additional occurrence records available.
- Footnote 3
Although there is limited dispersal measurement data available for Behr's Hairstreak, preliminary mark-recapture studies conducted at sites in the south Okanagan valley from 2004-2007 indicated a 100 m average seasonal dispersal (with some variation depending on climatic conditions during the flight season) and a 1200 m maximum dispersal distance (COSEWIC, 2012). The adult lifespan of Behr's Hairstreak is estimated at a minimum of 6 days. In absence of specific information, a daily movement distance of 100 m was considered to be a realistic precautionary estimate. Therefore the consensus of the British Columbia Southern Interior Invertebrates Recovery Team was to consider 600 m (i.e. 6 days x 100 m/day) as representing the best available information on the seasonal dispersal capabilities of Behr's Hairstreak, based on a combination of expert opinion, anecdotal observations, and estimated life-span of adult butterflies (Scott, 1973; S. Desjardins; J. Heron, pers. comm., 2012).
- Footnote 4
Behr's Hairstreak may have a mutualistic association with ants, in which ants protect the larvae from predation, and the larvae excrete amino acids that the ants consume. Should this association exist in Canadian populations of Behr's Hairstreak, it would occur on or within 5m of host plant Antelope Brush, as this where the larvae would occur.
- Footnote 5
Some of the known nectar host plants for Behr's Hairstreak are alien (non-native), i.e., Sweet-Clover, Tall Baby's-Breath. However, deliberate introduction of new alien plants including Sweet-Clover and Tall Baby's-Breath, and/or other alien plant species, would be considered an activity likely to destroy critical habitat. Given competitive advantage, alien species can become invasive (i.e., spread aggressively and cause competitive exclusion of natural habitats) within the Antelope-brush ecosystem.
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