Tuesday 21 May
Indiana bat (Myotis sodalis)
What’s the World’s Favourite Species?Find out here.
Indiana bat fact file
- Find out more
- Print factsheet
Indiana bat description
This small bat weighs the same as about three pennies, but is not the smallest of the 87 Myotis species. Myotis means ‘mouse ear’ and refers to the relatively small, mouse-like ears of these bats. This species gets the name ‘sodalis’, meaning ‘companion’, from its social behaviour (3). The Indiana bat has fine and fluffy fur that is dull greyish-chestnut with a black basal portion on the upperparts, whilst the underparts are pinkish to cinnamon (2). Several characteristics distinguish the Indiana bat from similar species; the light pink nose, small, delicate hind feet with sparse, short hairs that do not extend beyond the toes, and a calcar (the spur extending from the ankle) that has a slight keel (4). In addition, the ears and wing membranes have a dull appearance, and the fur is less glossy than that of the similar little brown bat (Myotis lucifugus) (3).
- Also known as
- social bat.
- Head-body length: 41 – 49 mm (2)
- Tail length: 27 – 44 mm (2)
- Wingspan: 240 – 267 mm (2)
- 5 – 11 g (2)
- U.S. Fish and Wildlife Service (2007) Indiana Bat (Myotis sodalis) Draft Recovery Plan: First Revision. U.S. Fish and Wildlife Service, Fort Snelling. Available at:
- Bat Conservation International:
- Relating to or belonging to a colony (a group of organisms living together in a group).
- A group of organisms living together. Individuals in the group are not physiologically connected and may not be related, such as a colony of birds.
- The act of searching for food.
- Accumulated droppings found where large colonies of animals such as seals, bats or birds occur; it is rich in plant nutrients.
- Hibernation is a winter survival strategy characteristic of some mammals in which an animal’s metabolic rate slows down and a state of deep sleep is attained. Whilst hibernating, animals survive on stored reserves of fat that they have accumulated in summer.
- A projecting ridge along a flat or curved surface, particularly down the middle.
- IUCN Red List (June, 2008)
- NatureServe. (June, 2007)
- US Fish and Wildlife Service. (2007) Indiana Bat (Myotis sodalis) Draft Recovery Plan: First Revision. U.S. Fish and Wildlife Service, Fort Snelling. Available at:
- Kentucky Bat Working Group (June, 2007)
- U.S. Fish and Wildlife Service (June, 2008)
- LaRoe, E.T., Farris, G.S., Puckett, C.E., Doran, P.D. and Mac, M.J. (1995) Our Living Resources: a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems. U.S. Department of the Interior, National Biological Service, Washington, DC.
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
Indiana bat biology
The Indiana bat is a migratory species that hibernates colonially during the winter. In late summer or early autumn they gather at their hibernating sites, or hibernacula, where they mate. The bats then cluster tightly together in groups of up to 5,000, hanging from the ceiling of the cave or mine, and enter hibernation (2). Whilst they mate in autumn, females do not fall pregnant until after they emerge from the caves in spring. This is achieved by the female storing the male’s sperm over winter and then ovulating in spring, allowing fertilization to occur (2) (3). After hibernation, the females are the first to migrate to wooded areas, whilst males and non-reproductive females may migrate later on, or remain near the hibernaculum (3). Migration to the summer habitat can involve travelling great distances of up to 575 kilometres. Groups of around 100 females gather together in the summer habitat, forming maternity colonies (3). Here, each female gives birth to only one young, which are able to fly within one month after birth, but stay with the maternity colony throughout their first summer (3) (4).
The Indiana bat is insectivorous, meaning it feeds only on insects. They can consume up to half their body weight in insects each night, and thus their role in controlling insect populations is a significant one (3). Bats also play an essential role in cave ecosystems by bringing in nutrients in the form of guano upon which many forms of life depend (6).Top
Indiana bat range
Occurs in the Midwest and eastern United States; from Oklahoma and Iowa, north and east to Michigan, New York and Vermont, and south to Alabama and Arkansas In summer it is apparently absent south of Tennessee; in winter it is apparently absent from Michigan, Ohio, and northern Indiana (2) (5).Top
Indiana bat habitat
During winter, Indiana bats hibernate in limestone caves, or occasionally abandoned mines. They have quite specific habitat requirements, preferring cool, humid caves with stable temperatures averaging two to seven degrees Celsius. In summer the Indiana bat can be found in wooded areas, where they usually roost under loose tree bark on dead or dying trees, or under bridges and in old buildings (3). They forage along river and lake shorelines, in the tree tops in floodplains and in upland forest (2).Top
Indiana bat status
Classified as Endangered (EN) on the IUCN Red List 2007 (1).Top
Indiana bat threats
Recently, the Indiana bat has been suffering from a decline in numbers due to a range of threats. During hibernation, the Indiana bat is vulnerable to human disturbance, which can cause direct mortality, or cause them to rouse and deplete their important energy reserves. Disturbance can be in the form of researchers, vandalism, and the commercialization of caves, allowing tourists to visit caves. Modifications to mines and caves, such as the construction of gates to restrict human access, alter airflow, temperature and humidity, to which the Indiana bat is very sensitive; or gates may not allow sufficient flight space for the bats and thus block them from a critical hibernation site (2) (3). As Indiana bats hibernate in very large numbers in only a few caves, this makes them particularly vulnerable to disturbance and natural disasters, as a large proportion of the total population can be affected by a single event (3).
The summer habitat is also threatened by habitat loss and degradation, caused by housing development, clear-cutting for agriculture, or forest management practices that result in a shortage of suitable roosting sites for breeding females (2). The use of pesticides is also likely to have affected the Indiana bat by reducing insect populations on which they depend (4)Top
Indiana bat conservation
As well as being classified as Endangered on the IUCN Red List 2007 (1), the Indiana bat is also listed as Endangered under the Endangered Species Act of 1973. As an outcome of this, the U.S. Fish and Wildlife Service has drawn up a recovery plan, with the goal of improving the status of the Indiana bat so that it can be removed from the Endangered Species List (3). To reach the goal a number of actions are required; conserving and managing the hibernacula and the summer habitat, conducting further essential research, and implementing a public information and outreach program. Dependent on funding and the implementation of conservation actions, it has been estimated that the species can fully recover by the year 2027 (3). At present, the primary conservation effort has been to control human access of caves by erecting properly designed gates that keep people from disturbing hibernating bats while maintaining temperature, humidity and allowing access for bats (3).Top
Find out more
For further information on the Indiana bat see:
AuthenticationThis information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: firstname.lastname@example.orgTop
More »Related species
Play the Team WILD game
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.