Plants and Animals
Myotis lucifugus Little brown bat
Coloring of little brown bats ranges from sandy brown to olive brown and they are lighter on the underside. Their ear membranes are hairless and black. Adult body mass ranges from between 5.5 to 11.0 grams and these bats are lightest in the spring when they emerge from hibernation. Forearm length ranges from 3.5 to 4.1 cm with a total wingspan ranging from 22.9 to 26.7 cm.
Status and Rank
US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G3 - Vulnerable
State Rank: S1 - Critically imperiled
|County||Number of Occurrences||Year Last Observed|
Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.
Before white-nosed syndrome devastated bat populations, little brown bats were the most common bat species in the northern half of the Lower Peninsula in Michigan accounting for roughly 60 percent of all mist net captures. They occur in a variety of habitats and their abundance is linked closely to availability mines and caves suitable for hibernation. Upon emergence from hibernation they travel throughout the state and will set up maternity roosts in man-made structures, utilizing barns, houses, large buildings, and the underside of bridges. They also roost in tree hollows and under loose bark. Little brown bats often forage over streams and ponds.
Natural Community Types
For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.
Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.
Little brown bat are generalists. Maintaining forest for roosting in and around open water for foraging would benefit this species. Protecting hibernacula from vandalism during winter is critical.
Active from second week of April to second week of October
Breeding from first week of September to fourth week of September
Parturition from first week of June to first week of July
Mist nets should be set perpendicular to travel corridors such as streams, rivers, and logging trails. A typical net setup is 7 to 9 meters (23-30 ft) high and up to 20 meters (66 ft) wide. Surveys should consist of a minimum of 1 net site per kilometer of habitat corridor and 2 sites per square kilometer of habitat. Mist netting at a site should be conducted for four nights and in at least two different locations within a site. Nets should be checked every 20 minutes from sunset to sunrise. The species is most active 25 minutes after sundown to 4 hours after sundown.
Survey Period: From third week of May to fourth week of July
Time of Day: Night
Air Temperature: Above 60 degrees
- Kurta, A. 2008. Bats of Michigan. Indiana State University Center for North American Bat Research and Conservation, Terre Haute, Indiana, 72 pp.
- U.S. Fish and Wildlife Service. 2018. Range-Wide India Bat Survey Guidelines.
- Wisconsin Department of Natural Resources. 2013. Wisconsin Little Brown Bat Species Guidance. Bureau of Natural Heritage Conservation, Wisconsin Department of Natural Resources, Madison, Wisconsin. PUB-ER-705