Northern Myotis - Myotis septentrionalis
General Description
Northern Myotis has relatively long ears (14-19 mm) extending < 5mm beyond the nose when pushed forward, a long pointed tragus, forearm length 34-38 mm, hind foot length 8-10 mm and tail length 35-42 mm; the calcar lacks a prominent keel (but a slight keel may be present), and the fringe of the tail is hairless or with only a few sparse hairs. Pelage and membranes are brown and usually the same color. Females are generally larger and heavier than males. Dental formula is I 2/3, C 1/1, P 3/3, M 3/3 (Nagorsen and Brigham 1993, Caceres and Barclay 2000, Adams 2003).
Diagnostic Characteristics
Northern Myotis was formerly considered a subspecies of Keen's Myotis (Myotis keenii). Northern Myotis can be distinguished in the hand from Myotis lucifugus by the longer ears (extending well beyond the snout when pushed forward) and tragus and relatively longer tail; pelage color is similar, but less glossy than in Myotis lucifugus. Characteristic frequency of call is slightly higher than for Myotis lucifugus (41-45 kHz vs. 37-43 kHz) and high frequency calls may reach to 120 kHz. Myotis evotis has darker membranes and paler pelage, and the ears are longer; characteristic frequency of calls is lower (33-38 kHz) than for Northern Myotis.
General Distribution
Western Hemisphere Range
Summary of Observations Submitted for Montana
Number of Observations: 2
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Relative Density
Recency
(Records associated with a range of dates are excluded from time charts)
Migration
The species may be partially migratory in far eastern Montana, but there is only one documented record, an individual hibernating in an abandoned coal mine near Culbertson in January 1978 (Swenson and Shanks 1979).
Habitat
In Montana, Northern Myotis have been located hibernating in an abandoned mine in riverbreaks habitat in Richland County (Swenson and Shanks 1979). Northern Myotis (Myotis septentrionalis) prefers cooler hibernacula than Myotis lucifugus and selects narrow crevices in which to hibernate. Summer day roosts are often in cavities or crevices behind peeling bark in trees, usually in tall, wide-diameter and partially dead hardwoods (Caceres and Barclay 2000).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (high, medium, or low) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2001, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species’ range and habitat requirements;
- Examining the observation records for each species in the state-wide point database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of “observations versus availability of habitat”.
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were associated as using an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system,
even if point observations were associated with that system.
High, medium, and low habitat quality was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species in the literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignments of habitat quality.
If you have any questions or comments on species associations with ecological systems, please contact Bryce Maxell at
bmaxell@mt.gov or (406) 444-3655.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at:
http://mtnhp.org/requests/default.asp) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species’ known geographic range.
Literature Cited
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2001. The wild mammals of Montana. Special Publication No. 12. Lawrence, KS: The American Society of Mammalogists. 278 p.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana’s amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
- Occasionally Associated with these Ecological Systems
Grassland Systems
Food Habits
No food habits information is available from Montana. Range-wide, Northern Myotis feed on a variety of insects, oftentimes gleaning insects from foliage and sometimes from the ground (Caceres and Barclay 2000).
Ecology
No information available for the Northern Myotis from Montana. During the summer, these bats emerge shortly after sunset to forage. Their activity is bimodal, peaking 1 to 2 hours and 7 to 8 hours after sunset. They are less gregarious than M. lucifugus or other Myotis species. They tend to be solitary or found in smaller clusters than other Myotis species; one of the largest hibernating clusters was of 300 individuals mixed with about 1000 Myotis lucifugus. It also may be overlooked in hibernacula as it tneds to occupy deep and narrow crevices. Longevity record is 18.5 years. Predators of Northern Myotis have not been reported (Caceres and Barclay 2000).
Reproductive Characteristics
No information from Montana. Elsewhere within the range, copulation occurs at hibernacula from late July to October (Caceres and Barclay 2000). Parturition in Montana may occur in late June or July; lactating females reported from late July through August in the Black Hills, South Dakota (Clark and Stromberg 1987).
Management
No management measures have been enacted specifically for the protection of Northern Myotis in Montana. Protection of bat winter roosting habitat (abandoned mines and caves) with gating should be beneficial to this species. Protection guidelines and management protocols designated for Townsend's Big-eared Bat, Corynorhinus townsendii (Pierson et al. 1999) are also appropriate for Northern Myotis, especially during winter, and can be used as a default protocol. So little is known about Northern Myotis in Montana, including its distribution and relative abundance, that standardized surveys of potential roosts and foraging habitats are desirable as the first step to identifying the spatial and temporal context in which this species is present in the state. This basic information will make it easier to design and implement appropriate and effective conservation guidelines for the protection of important habitats and roosts.
References
- Additional ReferencesLegend:
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Do you know of a citation we're missing?
Adams, R. A. 2003. Bats of the Rocky Mountain West: Natural History, Ecology and Conservation. University Press of Colorado: Boulder, CO, 289 pp.- Foresman, K. R. 2001. The Wild Mammals of Montana. American Society of Mammologists, Special Publication No. 12: Lawrence, KS, 278 pp.
- Reid, F. 2006. Peterson Field Guide to Mammals of North America, 4th Edition. Houghton Mifflin Company: Boston and New York, 608 pp.
- Swenson, J.E., and G.F SHANKS, Jr. 1979. NOTEWORTHY RECORDS OF BATS FROM NORTHEASTERN Montana. J. MAMMal. 60:650-652
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