Long-Eared Myotis (Myotis evotis) Potential Occurrence: Likely to Occur Status

Дата канвертавання24.04.2016
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Mammalia (Mammals): Chiroptera, Vespertillionidae

Long-Eared Myotis (Myotis evotis)

Potential Occurrence: Likely to Occur


Federal: None

State: None

Other: BLM:S

Species Description:

M. evotis has pale brownish to straw-colored pelage. It is distinguished from M. auriculus and M. thysanodes by having long (19 to 25 mm), glossy black ears and no distinct fringe of hairs along the edge of the uropatagium. M. evotis eats moths and small beetles, as well as flies, lacewings, wasps, and true bugs. In areas where M. evotis and M. auriculus are sympatric, M. evotis tends to eat more beetles. (From Bogan et. al. 2005)


Myotis evotis, a member of the Family Vespertilionidae, ranges across western North America from southwestern Canada (British Columbia, Alberta and Saskatchewan) to Baja California and eastward in the United States to the western Great Plains. (From Bogan et. al. 2005)

The long-eared myotis is widespread in California, but generally is believed to be uncommon in most of its range. It avoids the arid Central Valley and hot deserts, occurring along the entire coast and in the Sierra Nevada, Cascades, and Great Basin from the Oregon border south through the Tehachapi Mts. to the Coast Ranges. (From Harris 1990)

Life History & Threats:

This species is a slow flier and is often described as a hovering gleaner that feeds by eating prey off foliage, tree trunks, rocks, and from the ground. It generally leaves its roost for foraging after dark, but individuals have been caught as early as 0.5 h after sunset. M. evotis occurs in semiarid shrublands, sage, chaparral, and agricultural areas, but is usually associated with coniferous forests. Individuals roost under exfoliating tree bark, and in hollow trees, caves, mines, cliff crevices, sinkholes, and rocky outcrops on the ground. They also sometimes roost in buildings and under bridges. During the summer, females form small maternity colonies, whereas males and non-reproductive females roost alone or in small groups nearby. Females give birth to one young in late spring to early summer. Individuals have lived up to 22 years. Presumably, most individuals hibernate during the winter. (From Bogan et. al. 2005)

May be affected by closure of abandoned mines without surveys, recreational caving, some forest-management practices, and activities (such as highway construction, water impoundments, blasting of cliffs for avalanche control) that impact cliff faces or rock outcrops. (From Bogan et. al. 2005)

Habitat & Habitat Associations:

General Habitat:

This species has been found in nearly all brush, woodland, and forest habitats, from sea level to at least 2700 m (9000 ft), but coniferous woodlands and forests seem to be preferred. (From Harris 2000)

This species has a relatively poor urine concentrating ability, and probably requires water (Geluso 1978)…Feeds along habitat edges, in open habitats, and over water. (From Harris 2000)

Foraging Habitat:

Insects are caught in flight, gleaned from foliage, or occasionally taken from the ground. Foraging flight is slow and maneuverable. This species is capable of hovering…Usually less than 12 m (40 ft) above the ground….Feeds along habitat edges, in open habitats, and over water. (From Harris 2000)

Roosting, Hibernacula, and Nurseries:

The following roost sites used by M. evotis have been documented: loose bark in tall, open-canopied snags (Vonhof and Barclay 1996); pine stumps in south-facing clear-cuts with minimal vegetation overgrowth in younger forests, and conifer snags in older forests (Vonhof and Barclay 1997; Rabe et al. 1998); rock crevices (Chruszcz and Barclay 2002); caves (Barbour and Davis 1969); abandoned mines (Hendricks 1998; Altenbach et al. 2002; Hinman and Snow 2003; Ellison et al. 2004); and bridges (Keely 1998). (From Buseck and Keinath 2004)

Navo et al. (2002) reported swarming activity of M. evotis at a cave in Colorado (the first documentation of this behavior for this species), which suggested that they hibernated in that cave or one nearby. Another report found two M. evotis hibernating in a mine in Montana (Foresman 2001 in Schmidt 2003). Overall, little information is known about the winter activities or range of M. evotis. Hibernacula that have been documented for other bat species are usually in caves or mines (as is suspected with M. evotis) with temperatures that do not fluctuate or drop below 0°C, to prevent freezing (Tuttle and Taylor 1998). (From Buseck and Keinath 2004)

Selection of stumps and snags appeared to have the following characteristics: 1) moderate stages of decay, and therefore more potential for roost sites due to the sloughing of bark, 2) larger in diameter, providing thicker bark for more insulation (e.g., ponderosa pine), 3) taller than surrounding trees and/or vegetation (e.g., roost selection increased with the height of the stump), and 4) in open canopies providing easier access and more direct sunlight (Knight 1994; Vonhof and Barclay 1996, 1997; Rabe et al. 1998; Waldien et al. 2000). Suitable bridge roosts were characterized by a concrete bridge containing a 3/4 to 1-inch wide crevices at least 6 to 12-inches deep, located 10 feet or greater above the ground, sealed from rain water at the top, and receiving full sun for the majority of the day (Keely 1998). (From Buseck and Keinath 2004)

Conceptual Basis for GIS Model Development: We mapped potential habitat for this species as:

General Habitat:

  • brush, woodland, and forest vegetation types (i.e., all types of chaparral, cismontane woodland, broadleaf upland forest, coniferous forest, riparian woodland, and riparian forest)

Possible best habitat was identified as coniferous forests with an open canopy (< 40% canopy cover)

Roosts & Hibernacula: within the brush, woodland and forest vegetation types, we identified roosting sites and hibernacula as large stumps and snags, rock crevices, concrete bridges, buildings, and caves

Foraging Habitat:

  • perennial or seasonal watercourses, ponds

  • habitat edges were identified as the edges of grasslands (all types), chaparral (all types), woodland/forests (all types), and riparian woodland/forests (all types).

Potential Occurrence in the Galbreath Wildlands Preserve:

Habitat: Long-Eared Myotis can occur in a wide variety of habitats but prefer open coniferous forests. They are dependent on nearby water for drinking, habitat edges for foraging, and a variety of features (rocky outcrops, cliffs, crevices, hollow trees, snags) for roosting. Habitat quality for this species is moderate. Surface water is available year round at ponds and tributaries to Rancheria Creek, and potential roosting habitats (rocky outcrops, cliffs, snags) were also observed to be abundant during field reconnaissance surveys. However, the preferred habitat – open coniferous forest - only occurs in small fragmented locations (Figure 106) and edge habitats used for foraging are not common within Preserve boundaries.

Nearest Occurrence:

Documented Occurrences in Preserve: This species has not been documented in the Preserve. To our knowledge, no surveys have been conducted.

Nearest Occurrence to Preserve: Long-Eared Myotis has not been reported to occur in USGS quads adjacent to the Preserve.

Summary: We anticipate that this widespread coastal species is “Likely to Occur” in the Preserve. Conifers are widespread, foraging habitat is common immediately outside of the Preserve boundaries, and roosting areas may be abundant.


Altenbach SJ. State of Utah Natural Resources Division of Wildlife Resources . Long-Eared

Myotis Photo.

2010 July 1.

Bogan MA, Valdez EW, and KW Navo. 2005. Western Bat Working Group. Species

Account- Long-Eared Myotis.

vespertilonidae/myev.pdf> 2010 July 1.
Buseck RS and DA Keinath. 2004 October. Species Assessment for Western Long-Eared

Myotis (Myotis evotis) in Wyoming.

SpeciesAssessments/Long-eared%20Myotis%20-%20Final%20(Oct%202004).pdf> 2010

July 1.
Harris J. 2000. Long-Eared Myotis. California Wildlife Habitat Relationships System.

2010 July 1.

Species Account Description: Emily Harvey

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