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Contact information
For information on Wisconsin's rare vertebrate animals, contact:
Rich Staffen
Conservation Biologist
For information on Wisconsin's rare invertebrates, contact:
Jay Watson
Conservation Biologist

Little Brown Bat (Myotis lucifugus)



Little Brown Bat (Myotis lucifugus) is a Threatened species in Wisconsin. Its dorsal fur is a glossy dark-brown to olive-brown color with a lighter ventral side. The little brown bat is insectivorous and feeds on aquatic soft-bodied insects and is found roosting in warm microclimates provided by tree snags, bat houses, and buildings during the summer. It forages primarily over open water and along edge habitat. Little Brown Bats hibernate in caves and mines from October through April. Mating occurs in the fall, and females store sperm until emergence in the spring. Usually one pup is born in early June and matures in six weeks. See the species guidance document for avoidance measures and management guidance from the Natural Heritage Conservation Program.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Little Brown Bat (Myotis lucifugus). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where occurrences of this species meet NHI data standards and is not meant as a comprehensive map of all observations.

Note: Species recently added to the NHI Working List may temporarily have blank occurrence maps.

Documented locations of Myotis lucifugus in the Natural Heritage Inventory Database as of July 2015.
Summary Information
State StatusTHR
Federal Status in Wisconsinnone
State RankS2S4
Global RankG3
Tracked by NHIY

Species guidance

This document contains identification and life history information for Little Brown Bat. It also describes how to screen projects for potential impact to this species, lists avoidance measures, and provides general management guidance.

Little Brown Bat Species Guidance [PDF]



Little Brown Bat

Albino little brown bat

Photo © Jennifer Schehr.

Little Brown Bat

Photo ©  Wisconsin DNR.

Little Brown Bat

Photo ©  Wisconsin DNR.

Wildlife Action Plan

Wisconsin Wildlife Action Plan graphic

Natural community (habitat) associations

The table below lists the natural communities that are associated with Little Brown Bat. Only natural communities for which Little Brown Bat is "high" (score=3) or "moderate" (score=2) associated are shown. See the key to association scores for complete definitions. Please see the Wildlife Action Plan to learn how this information was developed.

Natural community Score
Black Spruce Swamp 3
Caves and Subterranean Cultural 3
Coldwater streams 3
Coolwater streams 3
Ephemeral Pond 3
Floodplain Forest 3
Forested Seep 3
Lacustrine Mud Flat 3
Large Lake--deep, hard, drainage 3
Large Lake--deep, hard, seepage 3
Large Lake--deep, soft, drainage 3
Large Lake--deep, soft+, seepage 3
Large Lake--shallow, hard, seepage 3
Large Lake--shallow, hard+, drainage 3
Large Lake--shallow, soft, drainage 3
Large Lake--shallow, soft, seepage 3
Mesic Floodplain Terrace 3
Mesic Prairie 3
Moist Sandy Meadow 3
Northern Sedge Meadow 3
Northern Tamarack Swamp 3
Northern Wet Forest 3
Northern Wet-mesic Forest 3
Riverine Impoundment - Reservoirs 3
Riverine Lake - Pond 3
Riverine Mud Flat 3
Small Lake--hard, bog 3
Small Lake--meromictic 3
Small Lake--other 3
Small Lake--soft, bog 3
Spring Pond, Lake--Spring 3
Springs and Spring Runs (Hard) 3
Springs and Spring Runs (Soft) 3
Warmwater rivers 3
Warmwater streams 3
Bog Relict 2
Boreal Forest 2
Central Poor Fen 2
Coastal Plain Marsh 2
Emergent Marsh 2
Floating-leaved Marsh 2
Lake Michigan 2
Mesic Cedar Forest 2
Muskeg 2
Northern Dry Mesic--late seral 2
Northern Hardwood Swamp 2
Northern Mesic Forest--late seral 2
Northern Mesic Forest--mid seral 2
Oak Opening 2
Oligotrophic Marsh 2
Open Bog 2
Patterned Peatland 2
Poor Fen 2
Sand Barrens 2
Shrub Carr 2
Southern Hardwood Swamp 2
Southern Mesic Forest 2
Southern Sedge Meadow 2
Submergent Marsh 2
Transportation-Utility Corridor 2
Wet-mesic Prairie 2
White Pine - Red Maple Swamp 2
Wild Rice Marsh 2

Ecological landscape associations

The table below lists the ecological landscape association scores for Little Brown Bat. The scores correspond to the map (3=High, 2=Moderate, 1=Low, 0=None). For more information, please see the Wildlife Action Plan.

This map shows the probability of Little Brown Bat occurring in each of Wisconsin's Ecological Landscapes.  Actual scores can be found in the table to the left.

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Landscape-Community combinations of highest ecological priority*

Ecological priorities are the combinations of natural communities and ecological landscapes that provide Wisconsin's best opportunities to conserve important habitats for a given Species of Greatest Conservation Need. The 10 highest scoring combinations are considered ecological priorities and are listed below. More than 10 combinations are listed if multiple combinations tied for 10th place. For more information, please see the Wildlife Action Plan.

Ecological LandscapeCommunity
Central Lake Michigan Coastal Lacustrine Mud Flat
Central Lake Michigan Coastal Warmwater rivers
Central Lake Michigan Coastal Warmwater streams
Central Sand Hills Coldwater streams
Central Sand Hills Lacustrine Mud Flat
Central Sand Hills Northern Wet Forest
Central Sand Hills Northern Tamarack Swamp
Central Sand Hills Warmwater rivers
Central Sand Plains Caves and Subterranean Cultural
Central Sand Plains Floodplain Forest
Central Sand Plains Northern Sedge Meadow
Central Sand Plains Northern Wet Forest
Central Sand Plains Riverine Impoundment - Reservoirs
Central Sand Plains Riverine Lake - Pond
Central Sand Plains Northern Tamarack Swamp
Forest Transition Black Spruce Swamp
Forest Transition Coldwater streams
Forest Transition Coolwater streams
Forest Transition Northern Wet Forest
Forest Transition Northern Wet-mesic Forest
Forest Transition Northern Tamarack Swamp
Forest Transition Warmwater rivers
Forest Transition Warmwater streams
Southeast Glacial Plains Caves and Subterranean Cultural
Southeast Glacial Plains Ephemeral Pond
Southeast Glacial Plains Floodplain Forest
Southeast Glacial Plains Mesic Prairie
Southeast Glacial Plains Riverine Mud Flat
Southeast Glacial Plains Small Lake--other
Southeast Glacial Plains Warmwater rivers
Southeast Glacial Plains Warmwater streams
Southern Lake Michigan Coastal Lacustrine Mud Flat
Southern Lake Michigan Coastal Warmwater streams
Southwest Savanna Lacustrine Mud Flat
Southwest Savanna Mesic Prairie
Southwest Savanna Spring Pond, Lake--Spring
Southwest Savanna Springs and Spring Runs (Hard)
Southwest Savanna Springs and Spring Runs (Soft)
Southwest Savanna Warmwater streams
Western Coulee and Ridges Caves and Subterranean Cultural
Western Coulee and Ridges Coldwater streams
Western Coulee and Ridges Coolwater streams
Western Coulee and Ridges Floodplain Forest
Western Coulee and Ridges Forested Seep
Western Coulee and Ridges Lacustrine Mud Flat
Western Coulee and Ridges Riverine Lake - Pond
Western Coulee and Ridges Riverine Mud Flat
Western Coulee and Ridges Spring Pond, Lake--Spring
Western Coulee and Ridges Springs and Spring Runs (Hard)
Western Coulee and Ridges Springs and Spring Runs (Soft)
Western Coulee and Ridges Warmwater rivers
Western Prairie Coldwater streams
Western Prairie Coolwater streams
Western Prairie Lacustrine Mud Flat
Western Prairie Mesic Prairie
Western Prairie Warmwater rivers
Western Prairie Warmwater streams

* Ecological priority score is a relative measure that is not meant for comparison between species. This score does not consider socio-economical factors that may dictate protection and/or management priorities differently than those determined solely by ecological analysis. Further, a low ecological priority score does not imply that management or preservation should not occur on a site if there are important reasons for doing so locally.

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Issues/threats and conservation actions

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the WWAP because lack of information can threaten our ability to successfully preserve and care for natural resources.

Threats/issues and conservations actions for rare animals

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Last revised: Thursday, October 08, 2020