Spotted bat (Euderma maculatum): COSEWIC status appraisal summary 2014
Special Concern
2014
Table of Contents
List of Figures
- Figure 1. Extent of occurrence of the Spotted Bat in Canada. Data from B.C. Ministry of Environment (2013). Red points are additional observations from the B.C. Conservation Data Centre (B.C. CDC unpubl. data 2014).
- Figure 2. Spotted Bat records in Washington since 1991. Source: Washington Department of Fish and Wildlife (Wiles, pers. comm. 2014).
Document Information
COSEWIC
Committee on the Status
of Endangered Wildlife
in Canada
COSEPAC
Comité sur la situation
des espèces en péril
au Cananda
Committee on the Status of Endangered Wildlife in Canada (COSEWIC) status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows:
COSEWIC. 2013. COSEWIC status appraisal summary on the Spotted Bat Euderma maculatum in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xv pp. (Species at Risk Public Registry website).
Production note:
COSEWIC acknowledges Brian Slough for writing the status appraisal summary on the Spotted Bat, Euderma maculatum,in Canada, prepared under contract with Environment Canada. This status appraisal summary was overseen and edited by Justina Ray, Co-chair of the COSEWIC Terrestrial Mammals Specialist Subcommittee.
For additional copies contact:
COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment Canada
Ottawa, ON
K1A 0H3
Tel.: 819-938-4125
Fax: 819-938-3984
E-mail: COSEWIC E-mail
Website: COSEWIC
Également disponible en français sous le titre Sommaire du statut de l’espèce du COSEPAC sur L’oreillard maculé (Euderma maculatum) au Canada.
COSEWIC Assessment Summary
Assessment Summary - November 2014
- Common name
- Spotted Bat
- Scientific name
- Euderma maculatum
- Status
- Special Concern
- Reason for designation
- This distinctly patterned bat is found in the dry intermontane grasslands of southern British Columbia. A cliff-roosting bat, its patchy distribution and specialized roosting needs suggest a relatively small population size. The main threats to foraging habitat in valley bottoms or roosting locations are urban development, land conversion for orchards and vineyards, roads, mining and exploration, recreational activities (e.g., rock climbing), and light and noise pollution. This bat may be susceptible to White-nose Syndrome if this disease spreads west. Its specialized habitat requirements and slow reproductive rate will affect recovery.
- Occurrence
- British Columbia
- Status history
- Designated Special Concern in April 1988. Status re-examined and confirmed in May 2004 and November 2014.
COSEWIC Status Appraisal Summary
- Scientific Name:
- Euderma maculatum
- English Name:
- Spotted Bat
- French Name:
- Oreillard maculé
- Range of occurrence in Canada:
- British Columba
Current COSEWIC Assessment:
- Designated Special Concern in April 1988. Status re-examined and confirmed in May 2004 and November 2014.
Evidence (indicate as applicable):
- Wildlife species:
- Change in eligibility, taxonomy or designatable units:
- No
Explanation:
There is no change.
Range
- Change in extent of occurrence (EO):
- yes
- Change in index of area of occupancy (IAO) :
- unk
- Change in number of known or inferred current locations*:
- yes
- Significant new survey information
- yes
Explanation:
EO was calculated as 10,600 km2 in the last status report and AO was described as ‘unknown’. There have been few directed surveys of this species since the last status report. Opportunistic records have increased the known distribution. Sarell et al. (2011) reported a significant westerly range extension with an auditory detection at Sebring Creek, Carpenter Lake, west of Lillooet. Otherwise, surveyors have reported the persistence of this species, using acoustic and visual surveys, within previously known range (Iredale and Ferguson 2007, Sarell et al. 2011, Lausen pers. comm. 2014). Although there is confidence in the delineation of the core distribution, search effort in some potential areas within and outside this distribution is still lacking (see below).
Based on BC Ministry of Environment (2013; Figure 2) EO of the Spotted Bat in Canada is 59,005 km2 (Figure 1), and the IAO (2x2 grid) was calculated as 472 km2, including 4 observations from the BC CDC dataset (B.C. Conservation Data Centre, unpubl. data 2014) not shown by BC Ministry of Environment (2013; Figure 2). The number of current locations that is each subject to a potential threatening event is unknown, but has likely increased since the last assessment as a result of some additional records and is certainly > 10.
* Use the IUCN definition of "location"
Population Information:
- Change in number of mature individuals:
- unk
- Change in population trend:
- unk
- Change in severity of population fragmentation:
- no
- Change in trend in area and/or quality of habitat:
- no
- Significant new survey information
- no
Explanation:
As of 2004, there were 80 records of Spotted Bats in British Columbia (COSEWIC 2004), and recent records assembled by the B.C. Conservation Data Centre (unpubl. data 2014) have increased that number to at least 93. However, these do not include all occurrence data for this species that have been received to date (Stipek, pers. comm. 2014).
Since the series of roost emergence counts reported in COSEWIC (2004), Iredale and Ferguson (2007) recorded incidental observations at Seton Lake and the Back Valley. Sarell et al. (2011) reported 3 confirmed and 9 potential auditory detections, but did not specify the locations of confirmed detections, except for the Sebring Creek site, which represented a westward extension to the known range. Lausen (pers. comm., 2014) captured two lactating females near previously known roosts in south Okanagan during one night of effort, and 7 individuals, including 4 lactating females and 2 volant juveniles, on the Fraser River near Lillooet in 2014. In the latter site, Spotted Bats were the only bat species captured and appeared to be abundant; by contrast there was no evidence of this species in 6 other surveyed sites in the area. Reproduction by Spotted Bats in B.C. had previously been reported by Leonard and Fenton (1983).
The BC Ministry of Environment (2013) cautions that surveys for Spotted Bats have not been systematic and that some regions such as the north Okanagan Valley and Fraser Valley have received little survey attention. Areas that have been surveyed were typically chosen due to a perceived high habitat potential for roosting, which includes cracks and crevices on cliff faces (BC Ministry of Environment 2013; Lausen, pers. comm. 2014).
The reasons for designation from the May 2004 COSEWIC assessment included the statement “It is considered the easiest and best censused species of bat in Canada”, which is now known to be incorrect. The occurrence and abundance of Spotted Bats across their range was estimated in the past using maternity roost emergence surveys and other standard survey methods. However, roost locations in much of the species’ range in BC outside the Okanagan Valley are either unknown or inaccessible. Standard bat capture methods often employ low-level mist nets, whereas intense effort using elevated mist nets is required to capture Spotted Bats (Rodhouse et al. 2005, Luce and Keinath 2007). The common acoustic survey method for bat detection using zero-crossing technology is inadequate for differentiating the lower frequency calls of the Spotted Bat (11-18 kHz) from background noise (Lausen pers. comm. 2014). Time expansion bat detecting systems, which provide full spectrum sonograms and high quality recording of Spotted Bat calls, have only been available for practical use (portability and affordability) for the past 5 years. Nevertheless, field workers may miss the signature of Spotted Bats if their detector is set to default settings or adjusted to settings that are too high to detect this species.
Spotted Bats are naturally patchy in distribution, and they tend to be found, even at relatively high abundance levels, where low-elevation and extensive cliff habitats occur in dry habitats, and are absent in large intervening areas (Luce and Keinath 2007, Lausen pers. comm. 2014). In summary, it is uncertain whether the Spotted Bat population in Canada numbers fewer than 1,000 mature individuals, as concluded by COSEWIC (2004). Overall survey effort for Spotted bats has been insufficient to reliably estimate numbers.
Threats:
- Change in nature and/or severity of threats:
- no
Explanation:
COSEWIC (2004) concluded that there were no obvious threats to habitats used for foraging or roosting by Spotted Bats and actual or imminent threats were limited to disturbance to cliff roosting sites, loss of riparian foraging habitat, and impact of pesticides on the moth prey base.
BC Ministry of Environment (2013) used IUCN-CMP (World Conservation Union – Conservation Measures Partnership) unified threats classification system (Conservation Measures Partnership (2010) in order to assess the threats to this species. The overall cumulative impact of multiple threats was considered Medium, based on 6 Low Impact (Level 1) threats: urban development, land conversion for agricultural purposes, roads, mining and exploration, renewable energy (e.g., wind turbines), recreational activities (e.g., rock climbing) and light and noise pollution. An additional threat not considered is the potential for flooding of valley bottoms, where specialized roosting habitats are located.
Pseudogymnoascus destructans, was identified as a potential threat of unknown magnitude. This pathogen has caused population declines in several species of cave-hibernating bats in eastern North America (see COSEWIC 2013), and has been spreading west (White-nose Syndrome.org 2014). The vulnerability of Spotted Bats to this disease, if it reaches British Columbia, is unknown, but may be low if the species hibernates in cliffs or crevices in B.C. or the U.S., rather than caves, as speculated by Nagorsen and Brigham (1993). One year (2013-14) of acoustic data collected by Lausen (pers. comm. 2014) in the National Wildlife Area on Vaseux Lake, detected Spotted Bats for the last time in 2013 in mid-October, and for the first time in 2014 in mid-March. This means that individuals either migrated from the area or hibernated locally for 5 months. A lack of genetic diversity across Oregon, Washington, and British Columbia suggests that this species does not migrate over long distances (Walker et al. 2014).
Protection:
- Change in effective protection:
- no
Explanation:
Over 90% of Spotted Bat range occurs outside of protected areas (COSEWIC 2004, BC Ministry of Environment 2013). Spotted Bat is listed as a species at risk under the BC Forest and Range Practice Act, enabling habitat management tools as per the Identified Wildlife Management Strategy (Province of British Columbia 2004); one Wildlife Habitat Area has been approved at Criss Creek near Kamloops to manage forestry and range activities for this species (BC Ministry of Environment 2013).
Rescue Effect:
- Change in evidence of rescue effect:
- yes
Explanation:
Global status is Apparently Secure (G4). The NatureServe rank of the species in Washington, which borders Spotted Bat range in British Columbia, is S3. It is ranked S2 or S3 in all other US states in the bat’s range (NatureServe 2014). Spotted Bats are not widespread in Washington state, and are not well surveyed. They have been recorded in 7 counties in the eastern part of the state (Hayes and Wiles 2013; Figure 2), but may be more common than formerly believed in Washington and Oregon due to the ineffectiveness of standard survey methods (Rodhouse et al. 2005, Luce and Keinath 2007, Hayes and Wiles 2013; NatureServe 2014).
Movements of individuals between British Columbia and Washington have not been documented, but there is a string of records extending northward through the Washington side of the Okanogan Valley to the BC border (Figure 2). Therefore, it seems likely that there are some movements between BC and Washington State (Wiles 2014). Similar habitat-related threats are evident on the Washington side of the border, although the area is somewhat less intensively developed than the BC side of the valley (Wiles 2014). The two records in the far eastern part of Washington (Pend d’Oreille county; Figure 2) are located in high cliff density habitat, but so far Spotted Bats have not been detected on the adjacent BC side of the border (Lausen, pers. comm. 2014).
Quantitative Analysis:
- Change in estimated probability of extirpation:
- no
Details:
none
Summary and Additional Considerations: [e.g., recovery efforts]
Less than 5% of the Spotted Bat’s global range is in Canada. This bat is restricted to the dry interior of southern BC (Bunchgrass, Ponderosa Pine and Interior Douglas-fir biogeoclimatic zones). The availability of suitable cliffs and crevices that offer protection, suitable thermal conditions for roosting, and proximity to feeding areas and water sources may be limiting and may explain the apparently discontinuous distribution of this species. Expansion of human population and land conversions continue to occur in this area of BC, but lack of monitoring of Spotted Bat populations, distributions, or habitats precludes understanding of impacts of such changes. The overall population trend is unknown, and previously used survey methods are now believed to have been insufficient to estimate occurrence and abundance. Six low-impact threats have been identified by the BC Ministry of Environment, leading to an overall impact of Medium. The likelihood of rescue from the United States is unclear. A Management Plan with a threats assessment was published in 2013 (BC Ministry of Environment 2013).
The Spotted Bat is now ranked S3S4 (vulnerable to apparently secure) in British Columbia (B.C.).
et al. 2014).
Acknowledgements:
Thanks to David F. Fraser for coordinating information gathering at the BC Ministry of Environment. Jenny Wu, COSEWIC Secretariat assisted with the preparation of distribution maps and the calculation of extent of occurrence, area of occupancy, and index of area of occupancy. Cori Lausen (WCS Canada) provided important additional information and insight.
Authorities contacted and reviewers:
*Denotes that information was provided by authority contacted.
Robert Anderson, Canadian Museum of Nature
*Syd Cannings, Canadian Wildlife Service
*David F. Fraser, BC Ministry of Environment
*Neil Jones, COSEWIC Secretariat (ATK)
*Cori Lausen, Wildlife Conservation Society Canada
Rhonda L. Milliken, Canadian Wildlife Service
*Dean Nernberg, National Defence
*Marie-France Noel, Canadian Wildlife Service
*Katrina Stipek, BC Conservation Data Centre
*Leah Westereng, BC Ministry of Environment
Gary Wiles, Washington Department of Fish and Wildlife
Information Sources
B.C. Conservation Data Centre unpubl. data 2014. Data received by email on January 22, 2014, from K. Stipec, British Columbia Conservation Data Centre, Ministry of Environment Victoria, B.C.
B.C. Ministry of Environment. 2013. Management plan for the spotted bat (Euderma maculatum) in British Columbia. B.C. Ministry of Environment, Victoria, BC. iv + 21 pp.
Conservation Measures Partnership. 2010. Threats taxonomy. Web site: [Accessed March 7, 2014].
COSEWIC 2004. COSEWIC assessment and update status report on the spotted bat Euderma maculatum in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 26 pp. Species at Risk Public Registry
COSEWIC. 2013. In Press. COSEWIC assessment and status report on the Little Brown Myotis Myotis lucifugus, Northern Myotis Myotis septentrionalis and the Tri-colored Bat Perimyotis subflavus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xxiv + 93 pp.. (Species at Risk Public Registry).
Hayes, G. and G. J. Wiles. 2013. Washington bat conservation plan. Washington Department of Fish and Wildlife, Olympia, Washington. 138+viii pp..
Iredale, F., and G. Ferguson. 2007. Auditory survey of the spotted bat in the Kamloops Supply Area. Prepared by the British Columbia Conservation Corps for B.C. Ministry of Environment and B.C. Conservation Foundation.
Lausen, C. pers. comm. 2014. Email correspondence with J. Ray, August 2014. Associate Conservation Scientist, Wildlife Conservation Society Canada, Toronto, ON, and Birchdale Ecological, Ltd., batRus Division, Birchdale, BC.
Leonard, M.L., and M.B. Fenton. 1983. Habitat use by spotted bats (Euderma maculatum, Chiroptera: Vespertilionidae): roosting and foraging behaviour. Canadian Journal of Zoology 61:1487–1491.
Luce, R.J. and D. Keinath. 200). Spotted Bat (Euderma maculatum): a technical conservation assessment. Species Conservation Project [Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/assessments/spottedbat.pdf [Accessed September 1, 2014].
Nagorsen, D.W., and R.M. Brigham. 1993. Bats of British Columbia. UBC Press, Vancouver, BC. 164 pp.
NatureServe. 2014. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Web Site: [Accessed: March 7, 2014].
Province of British Columbia. 2004. Identified wildlife management strategy. B.C. Min. Environ., Victoria, BC.
Rodhouse, T.J., M.F. McCaffrey, and R.G. Wright. 2005. Distrtibution, foraging behavior, and capture results of the spotted bat (Euderma maculatum) in central Oregon. Western North American Naturalist 65:215-222.
Sarell, M, J. Hobbs, and F. Iredale. 2011. Bridge River bat assessment, 2010. Prepared for British Columbia Hydro Bridge Coastal Fish and Wildlife Restoration Program and for Matt Manuel-Lillooet Tribal Council. Project #: 51463. 57 pp.
Stipec, K. pers. comm. 2014. Email correspondence with J. Ray, September 2014. British Columbia Conservation Data Centre, Ministry of Environment.
Walker, F., J. Foster, and C. Chambers. 2014. Spotted bat population genetics across time and space. Paper presented at North American Society for Bat Research. Albany, NY, October.
White-nose Syndrome.org. 2014. White-nose syndrome map. U.S. Fish and Wildlife Service, Department of the Interior, Washington, D.C. . Accessed 10 Sept. 2014.
Wiles, G. pers. comm. 2014. Email correspondence with J. Ray, September 2014. Wildlife Program, Diversity Division, Washington Department of Fish and Wildlife.
Technical Summary
- Scientific Name:
- Euderma maculatum
- English Name:
- Spotted Bat
- French Name:
- Oreillard maculé
- Range of occurrence:
- British Columbia
Demographic Information
Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines(2011) is being used).
- Unknown
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?
- Unknown
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]
- Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations]
- Unknown
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations]
- Unknown
[Observed, estimated, inferred or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.
- Unknown
Are the causes of the decline clearly reversible and understood and ceased?
- Unknown
Are there extreme fluctuations in number of mature individuals?
- No
Extent and Occupancy Information
Estimated extent of occurrence
- 59,005 km²
Index of area of occupancy (IAO, Always report 2x2 grid value)
- 472 km²
Is the population "severely fragmented" i.e., >50% of its total area of occupancy is in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a large distance?
- No
Number of locations* (use plausible range to reflect uncertainty)
- Unknown, but many more than 10
Is there an observed continuing decline in extent of occurrence?
- No
Is there an observed continuing decline in index of area of occupancy?
- No
Is there an [observed, inferred, or projected] continuing decline in number of subpopulations?
- Unknown
Is there an [observed, inferred, or projected] continuing decline in number of locations*?
- No
Is there an [observed, inferred, or projected] continuing decline in [area, extent and/or quality] of habitat?
- No
Are there extreme fluctuations in number of populations?
- No
Are there extreme fluctuations in number of locations?
- No
Are there extreme fluctuations in extent of occurrence?
- No
Are there extreme fluctuations in index of area of occupancy?
- No
*See Definitions and Abbreviations on COSEWIC website and IUCN 2010 for more information on this term.
Number of Mature Individuals (in each subpopulation)
Subpopulation (give plausible ranges):
N Mature Individuals
- Unknown
Quantitative Analysis
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].
- N/A
Threats (actual or imminent, to populations or habitats)
Urban development, land conversion for agricultural purposes, roads, mining and exploration, renewable energy (e.g., wind turbines), recreational activities (e.g., rock climbing), light and noise pollution, and potential for flooding in valley habitats.
Rescue Effect (immigration from outside Canada)
Status of outside population(s) most likely to provide immigrants to Canada?
- S3 in Washington
Is immigration known or possible?
- Unknown, but possible
Would immigrants be adapted to survive in Canada?
- Yes
Is there sufficient habitat for immigrants in Canada?
- Yes
Is rescue from outside populations likely?
- Unknown
Data-Sensitive Species
- Is this a data-sensitive species?
- No
Status History
- COSEWIC: Designated Special Concern in April 1988. Status re-examined and confirmed in May 2004 and November 2014.
Status and Reasons for Designation:
- Status:
- Special Concern
- Alpha-numeric code:
- Not applicable
- Reasons for designation:
- This distinctly patterned bat is found in the dry intermontane grasslands of southern British Columbia. A cliff-roosting bat, its patchy distribution and specialized roosting needs suggest a relatively small population size. The main threats to foraging habitat in valley bottoms or roosting locations are urban development, land conversion for orchards and vineyards, roads, mining and exploration, recreational activities (e.g., rock climbing), and light and noise pollution. This bat may be susceptible to White-nose Syndrome if this disease spreads west. Its specialized habitat requirements and slow reproductive rate will affect recovery.
Applicability of Criteria
- Criterion A (Decline in Total Number of Mature Individuals):
- Not applicable. No declines
- Criterion B (Small Distribution Range and Decline or Fluctuation):
- Not applicable. IAO is below 500 km 2, but is likely underestimated. EO > 2000 km 2.
- Criterion C (Small and Declining Number of Mature Individuals):
- Not applicable. Population may be small, but no evidence of decline.
- Criterion D (Very Small or Restricted Population):
- Not applicable. Population numbers unknown, but may be small overall.
- Criterion E(Quantitative Analysis):
- Not applicable. No quantitative analysis.
COSEWIC History
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.
COSEWIC Mandate
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.
COSEWIC Membership
COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.
Definitions (2014)
- Wildlife Species
- A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.
- Extinct (X)
- A wildlife species that no longer exists.
- Extirpated (XT)
- A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.
- Endangered (E)
- A wildlife species facing imminent extirpation or extinction.
- Threatened (T)
- A wildlife species likely to become endangered if limiting factors are not reversed.
-
Special Concern (SC)
(Note: Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.) - A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.
-
Not at Risk (NAR)
(Note: Formerly described as “Not In Any Category”, or “No Designation Required.”) - A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.
-
Data Deficient (DD)
(Note: Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” [insufficient scientific information on which to base a designation] prior to 1994. Definition of the [DD] category revised in 2006.) - A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.
The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.
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