The southeastern myotis (''Myotis austroriparius'') is a small

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

found throughout the

Gulf Coast The Gulf Coast of the United States, also known as the Gulf South or the South Coast, is the coastline along the Southern United States where they meet the Gulf of Mexico. The coastal states that have a shoreline on the Gulf of Mexico are Tex ...

al Plain and the Lower

Mississippi Mississippi ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the s ...

Alluvial Plain of the southeastern United States.

Description

The southeastern myotis weighs 5–8 g. Its diet consists predominantly of

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s. All species of the genus ''Myotis'', including the southeastern bat, rest by day and forage at night. They often hunt and feed over water. The feeding flights usually alternate with periods of rest, during which the bats hang to digest their catch. The southeastern bat has a

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the opposite wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingsp ...

of about 9-11 inches. Pelage varies from gray to bright orange-brown, with females generally being more brightly colored than the males. Southeastern bats are unique among ''Myotis'' of the United States in the production of twins; all other ''Myotis'' females usually produce one baby. This species is occasionally observed roosting with

Rafinesque's big-eared bat Rafinesque's big-eared bat (''Corynorhinus rafinesquii''), sometimes known as the southeastern big-eared bat, is a species of vesper bat native to the southeastern United States. Description As its name implies, this species has ears over an in ...

Range

The range of this species includes southern

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

and

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...

in the north, westward into southeastern

Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...

, western Tennessee and

Arkansas Arkansas ( ) is a landlocked state in the West South Central region of the Southern United States. It borders Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, Texas to the southwest, and Oklahoma ...

, and northeastern

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

, and eastward to the southern part of

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

. Disjunct populations of this species occur in the

Ohio River Valley The Ohio River () is a river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing in a southwesterly direction from Pittsburgh, Pennsylvania, to its mouth on the Mississippi River in Cairo, ...

Kentucky Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...

, and the majority of the population lives in the northern half of the peninsula of

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

Ecology

Southeastern myotis are an important food source for

barred owl The barred owl (''Strix varia''), also known as the northern barred owl, striped owl or, more informally, hoot owl or eight-hooter owl, is a North American large species of owl. A member of the true owl family, Strigidae, they belong to the genus ...

s, particularly in the nesting season.Bergstrom, B. J., & Smith, M. T. (2017). Bats as Predominant Food Items of Nesting Barred Owls. Southeastern Naturalist, 16(1), N1-N4. They are less important as a food source outside of the nesting season.

Diet

The diet of the southeastern myotis diverges from many other ''Myotis'' species by lacking high diet diversity. Their diet diversity index of 3.26 is derived from a diet consisting of 59.0% trichopterans. This species was observed consuming few arachnids and coleopterans. Their diet is most similar to eastern pipistrelle than any other species of ''Myotis'' in their consumption of caddisflies.

Habitat associations

Bottomland hardwood forests are facets of southeastern myotis ecology. This species roosts and forages near water. Bottomland hardwood forests typically contain bald cypress and water tupelo which are common roosting trees of bottomland bats. Suitable habitats consist of trees of sufficient size and maturity sufficient for tree cavities to form. There is a positive correlation between captures of this species with percent oaks and a negative correlation with percent bald cypress. A direct relationship for this species exists with increased captures in younger forests of high stem density, low canopy height, and increasing ground cover. They are also known to roost in caves, cisterns, abandoned buildings, and under bridges. The southeastern myotis shows preference for roost trees with the smallest DBH values available and tend to roost in densely packed clusters at cavity apexes.

Conservation

The southeastern myotis is currently listed (informally) by the U.S. Fish and Wildlife Service as a species of management concern. This species is associated with bottomland hardwood forests. This habitat type has suffered a loss of land cover with the estimation of only 15-25% of pre-colonial forested wetlands remaining in the southeastern United States. This species lives in a different forest system than species known as benefitting from forest harvests or thinning. Selectively logging non-cavity trees may leave roost trees, but it could potentially cause alternative disturbances to this species. Some habitats are impacted by nearby areas with extensive agricultural development from lack of sufficient buffering. Flood pulses common to bottomland ecosystems could potentially impact the species. These inundations can cause drowning of maternity colonies or reduced availability of prey by disrupting larval insects.

References

*Jones, C. and R. W. Manning. 1989. Myotis austroriparius. Mammalian Species 332:1–3. *Harvey, M. J., J. S. Altenbach, and T. L. Best. 1999. Bats of the United States. Published by the Arkansas Game and Fish Commission in cooperation with the Asheville Field Office, U.S. Fish and Wildlife Service. {{Authority control Mouse-eared bats Bats of the United States Fauna of the Southeastern United States Mammals described in 1897