New Jersey Field Office
Northeast Region

Indiana Bat (Myotis sodalis) [endangered]

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Additional Information

Indiana bat


Winter- caves and mines
Summer- wooded areas

Flying insects (including mosquitos!)

Main Threats:
Loss of forested summer habitats
Environmental contaminants
White-Nose Syndrome

Fun Fact:
Highly social, female Indiana bats form in maternity colonies to raise their pups.


The Indiana bat was federally listed in 1967 and classified as an endangered species in 1973.

The Indiana bat is a small, brown mammal about 1.5 to 2 inches long. This species closely resembles the little brown bat, from which it can be distinguished by small differences in fur coloration and the structure of the feet. As with all eastern U.S. bat species, Indiana bats feed almost exclusively on insects.

Each fall from late August through October, Indiana bats migrate from their summer habitats to congregate in the vicinity of their hibernation sites, which include caves and abandoned mine shafts. During this time, the bats engage in mating activity and feed in the surrounding area to build the fat reserves needed during hibernation. The bats then hibernate from late October to April, the precise timing dependent on climatic conditions. After emerging from hibernation, Indiana bats forage in the vicinity of the hibernation site before migrating to summer habitats. Studies indicate that Indiana bats typically forage within 10 miles of hibernacula before and after hibernation.

When not hibernating, Indiana bats roost under loose tree bark by day, and forage for flying insects in and around the tree canopy at night. A variety of upland and wetland habitats are used as foraging areas, including flood plain, riparian (along rivers), and upland forests; pastures; clearings with early successional vegetation; cropland borders; and wooded fencerows. Preferred foraging areas are streams, associated flood plain forests, and impounded bodies of water such as ponds and reservoirs.

During the summer months, numerous female bats roost together in maternity colonies under the loose bark of dead or dying trees within riparian, flood plain, and upland forests. Maternity colonies use multiple roosts in both living and dead trees. Female Indiana bats raise a single offspring each year. Adult males usually roost in trees near maternity roosts, but some males remain near the hibernaculum and have been found in caves and mines during the summer.

Protection of Indiana bats during all phases of their annual life cycle is essential to preserving this species. Threats to the Indiana bat include disturbance or killing of hibernating and maternity colonies; vandalism and improper closure of hibernacula; fragmentation, degradation, and destruction of forested summer habitats; and use of pesticides and other environmental contaminants. In recent years, White Nose Syndrome has also emerged as a major threat to the Indiana bat and many other bat species.


Indiana bat distribution in New Jersey (click for full-size)
Map of Indiana bat distribution in NJ

Species Range: Indiana bats occur in the forests and caves of the Northeast and Southeast but primarily in the Midwest.

Distribution in New Jersey: The Indiana bat is known to occur in Sussex, Passaic, Morris, Union, Essex, Somerset, and Hunterdon Counties. The species' geographic range (where bats may occur) also includes Warren and parts of Bergen, Middlesex, and Mercer Counties. See Bat Municiaplity List [PDF].

Examples of actions that may affect this species

The following is provided as technical assistance only and is not intended as a comprehensive list of all activities that may affect this species.

Within or above any cave or mine:
  • any activity

Within areas of known fall swarming habitat (0.25 mile around hibernacula entranceways) or known fall foraging habitat (10 miles around hibernacula):

  • clearing trees over 5 inches in diameter at breast height (dbh) between April 1 and November 15
  • clearing greater than 0.5 acre of trees at any time of year
  • new or increased discharges of pesticides (e.g., herbicides, fungicides, insecticides, rodenticides) or other environmental contaminants
  • construction of wind turbines

Within areas of known summer maternity habitat:

  • clearing trees over 5 inches dbh between April 1 and September 30
  • clearing greater than 0.5 acre of trees at any time of year
  • removal, modification or disturbance of known roost trees
  • new or increased discharges of pesticides or other environmental contaminants
  • construction of wind turbines

Within areas of potential summer habitat (within the geographic range but in areas not yet surveyed for the presence or absence of this species):

  • clearing trees over 5 inches dbh between April 1 and September 30
  • clearing greater than 1 acre of trees at any time of year
  • large-scale pesticide application that could depress insect populations
  • construction of wind turbines

Best Management Practices

The following Best Management Practices are examples of typical Conservation Measures frequently recommended by the New Jersey Field Office in the course of consultation or technical assistance.

  • Seasonally restrict clearing of trees greater than 5 inches dbh from April 1 to September 30 within the geographic summer range of the Indiana bat. Extend the seasonal restriction to November 15 if within 10.0 miles of a hibernaculum.
  • Minimize tree clearing, especially of highly suitable roost trees including snags (dead trees), shagbark hickories (Carya ovata), other trees with shaggy or exfoliating bark, and trees of any species over 26 inches dbh; see Characteristics of Indiana Bat Summer Habitat.
  • Avoid impacts to known roosts during any time of year.
  • Avoid or minimize impacts to known roosting/foraging areas any time of year.
  • Permanently protect known roosting/foraging habitat.
  • Maintain forested connections (e.g. hedgerows) between known foraging/roosting areas.
  • Minimize forest fragmentation (i.e.consider the landscape when laying out a project).
  • Avoid disturbance to riparian areas. Within areas of known fall foraging, summer maternity, and migration route habitats, preserve and restore wooded upland buffers at least 150-feet-wide on wetlands and open waters, and at least 300-feet-wide where possible and/or required by State regulation.
  • Use bright flagging/fencing to demarcate trees that will be protected vs. cleared.
  • Replant areas where trees have been disturbed for temporary activities or work space. Preferentially replant suitable roost tree species; See Characteristics of Indiana Bat Summer Habitat.
  • Minimize access to areas of known roost sites to prevent disturbance.
  • Minimize discharges of pesticides and other environmental contaminants in areas of known Indiana bat habitat. Avoid large-scale use of insecticides throughout the species’ geographic range.
  • Avoid use of chemicals (e.g., copper sulfate) in stormwater basins.
  • For forestry activities, implement the Service’s Forest Management Recommendations for Indiana Bats.
  • Coordinate with the Service early in planning for any activity in or above a cave or mine, or for any proposed wind power facilities within the geographic range of the Indiana bat.
  • Minimize potential lighting impacts (e.g.downward facing lights, shields, timers).

Please note the following REQUIRED information when requesting consultation or technical assistance from the Service: For projects in municipalities with known or potential occurrence of the Indiana bat, please indicate whether or not tree clearing is proposed. If so, describe the species, size (diameter at breast height), and number (or acres) of trees proposed for removal, and indicate whether clearing of tress >5 inches in diameter at breast height will be seasonally restricted (from April 1 to November 15 in municipalities with Hibernation occurrence; from April 1 to September 30 in municipalities with Maternity or Potential occurrence).

What to do if this species occurs on your property or project site

  • Contact the Service early in planning for any project or activity that may affect the Indiana bat or its habitat. See New Jersey Field Office Procedures for Consultation and Technical Assistance for instructions, and please note the REQUIRED information listed above. Through the technical assistance or consultation processes of the Endangered Species Act, the Service will provide project-specific recommendations to avoid or minimize adverse effects to listed species.
  • Individual landowners with suitable habitat can also contact the Service for site-specific, proactive conservation recommendations. In addition, technical and/or material assistance may be available through various State and or Federal programs to restore or maintain Indiana bat habitat. Most land in New Jersey is privately owned. Voluntary conservation efforts by New Jersey's residents are critical in the conservation and recovery of threatened and endangered species.
  • Also see "Endangered Species and You" Frequently Asked Questions.

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Last updated: April 11, 2019
New Jersey Field Office
Northeast Region Ecological Services
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