Animal Diversity Web

Ge­o­graphic Range

My­otis septen­tri­on­alis is widely but sparsely dis­trib­uted across forested re­gions of the east­ern United States. It ranges across south­ern Canada and up to New­found­land. It ex­tends down into Florida, through the south cen­tral states and through the Dako­tas, into east­ern British Co­lum­bia. In the Co­lum­bia Basin M. septen­tri­on­alis in­hab­its sev­eral dif­fer­ent re­gions in­clud­ing Cran­brook, In­ver­mere, Golden and Rev­el­stoke for­est dis­tricts (Troues­sart, 1999). It has also been found scat­tered through­out east­ern, cen­tral and north­ern British Co­lum­bia in­clud­ing the Peace River, Rev­el­stoke and Liard River areas (Bat Con­ser­va­tion In­ter­na­tional, 2001). (Bat Con­ser­va­tion In­ter­na­tional, Inc, 2001; Troues­sart, 1999)

• Biogeographic Regions
• nearctic
  • native

Habi­tat

North­ern bats are as­so­ci­ated with bo­real forests. In British Co­lum­bia they are found in the wet forests of the in­te­rior cedar-hem­lock bio­geo­cli­matic zone. In areas of North Amer­ica and Canada these bats choose ma­ter­nity roosts in build­ings, under loose bark, and in the cav­i­ties of trees. Caves and un­der­ground mines are their choice sites for hi­ber­nat­ing. (Troues­sart, 1999)

• Habitat Regions
• temperate

• Terrestrial Biomes
• forest

Phys­i­cal De­scrip­tion

My­otis septen­tri­on­alis is a medium sized bat best rec­og­nized by its long rounded ears, which ex­tend be­yond the tip of the nose when laid for­ward. It has a com­par­a­tively longer tail and larger wing area than My­otis species of sim­i­lar size; these struc­tural adap­ta­tions are as­so­ci­ated with its glean­ing for­ag­ing strat­egy (Al­tenbach et. al., 2001).

The total body length of north­ern bats is 78 mm. The tail mea­sures 26 mm, the foot mea­sures 9 mm, the ears mea­sure 17 to 19 mm, and the fore­arm mea­sures 35 mm. North­ern bats have a wingspan rang­ing be­tween 23 and 26 cm. These bats weigh 6 to 9 grams. The fe­males of this species are gen­er­ally larger and heav­ier than the males (Al­tenbach et. al., 2001).

The pelage is a dull yel­low/brown, with a pale gray ven­tral side, and dull, brown shoul­der spot­ting (Troues­sart, 1999). My­otis septen­tri­on­alis has a long, nar­row, sharp-pointed tra­gus, and the cal­car lacks a keel (Texas Tech­ni­cal Uni­ver­sity, 1997). Its skull is nar­row with a rel­a­tively long ros­trum. Its den­tal for­mula is that of M. cal­i­for­ni­cus: I 2/3, C 1/1, Pm 3/3, M 3/3 X 2 = 38. (Al­tenbach, J. S. and Har­vey, M. J., 2001; Texas Tech­ni­cal Uni­ver­sity, 1997; Troues­sart, 1999)

• Other Physical Features
• endothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger

• Range mass

  6 to 9 g

  0.21 to 0.32 oz

• Average length

  78 mm

  3.07 in

• Range wingspan

  23 to 26 cm

  9.06 to 10.24 in

Re­pro­duc­tion

Dur­ing cop­u­la­tion, a male north­ern bat mounts a fe­male from be­hind, oc­ca­sion­ally grasp­ing the fe­male's neck with his teeth (Bar­clay et. al., 2000). North­ern bats are promis­cu­ous. (Cac­eres and Bar­clay, May 12, 2000)

• Mating System
• polygynandrous (promiscuous)

Mat­ing oc­curs in au­tumn when groups of a few hun­dred are formed and pairs cop­u­late be­fore going into hi­ber­na­tion (Troues­sart, 1999).

The fe­males store sperm in their uteri dur­ing hi­ber­na­tion; ovu­la­tion will not occur until they emerge in the spring. Ges­ta­tion lasts 50 to 60 days, after which a sin­gle young is born. In British Co­lum­bia lim­ited breed­ing in­for­ma­tion sug­gests that young are born in late June or early July. (Troues­sart, 1999)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• viviparous
• sperm-storing
• delayed fertilization

• Breeding season

  These bats breed in autumn.

• Range number of offspring

  1 to 1

• Range gestation period

  50 to 60 days

• Average weaning age

  30 days

North­ern bats are born help­less and com­pletely de­pen­dent on their moth­ers. Fe­male north­ern bats nurse their young for about a month. Males do not help care for the young.

• Parental Investment
• altricial
• pre-fertilization
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifes­pan/Longevity

In­di­vid­u­als have been known to live up to 18.5 years. (Bogan, M. A. and Valdez, E. W., De­cem­ber 14, 2000)

• Typical lifespan
  Status: wild

  18.5 (high) years

• Average lifespan
  Status: wild

  18.5 years

Be­hav­ior

Dur­ing the sum­mer north­ern bats are com­monly found in higher den­si­ties around the north­ern areas of their range, as they are es­pe­cially re­liant upon the richly forested habi­tats in the north around this time (Al­tring­ham, 1996).

Oc­ca­sion­ally, these bats may be found roost­ing with other bat species, al­though they are much less so­cial than other mem­bers of the genus My­otis. The sexes roost sep­a­rately; how­ever, re­pro­duc­tive fe­males may form small ma­ter­nity colonies of less than 60 in­di­vid­u­als (Al­tring­ham, 1996).

In late sum­mer or early au­tumn the bats gather and move to the places where they will hi­ber­nate, trav­el­ing up to 56 kilo­me­ters from their sum­mer habi­tat. They gen­er­ally hi­ber­nate alone al­though they some­times form very small groups. Dur­ing hi­ber­na­tion these bats pre­fer moist, still, nar­row crevices where tem­per­a­tures may be as low as 1.6 de­grees Cel­sius. Hi­ber­na­tion may last for 8 to 9 months in the north­ern lat­i­tudes; length of hi­ber­na­tion varies among the var­i­ous lat­i­tudes and en­vi­ron­ments. The same hi­ber­nac­ula are often in­hab­ited more than once al­though not nec­es­sar­ily in se­quen­tial sea­sons. (Al­tring­ham, John D., 1996; Cac­eres and Bar­clay, May 12, 2000)

• Key Behaviors
• flies
• nocturnal
• motile
• migratory
• hibernation
• solitary
• social

Com­mu­ni­ca­tion and Per­cep­tion

Noth­ern bats use pas­sive lis­ten­ing and echolo­ca­tion to lo­cate in­sects rest­ing on leaves, tree trunks, or on build­ings. (Bogan, M. A. and Valdez, E. W., De­cem­ber 14, 2000)

• Perception Channels
• tactile
• acoustic
• echolocation
• chemical

Food Habits

My­otis septen­tri­on­alis emerges shortly after sun­set to hunt. Hunt­ing oc­curs over small ponds, for­est clear­ings and for­est edges at a height of 1 to 3 me­ters. Hunt­ing is cou­pled with pe­ri­odic rests (night roost­ing), fol­lowed by a sec­ond peak of hunt­ing just be­fore dawn (Troues­sart, 1999).

In gen­eral, these bats con­sume a va­ri­ety of smaller night-fly­ing in­sects, but they may some­times glean sit­ting prey as well.

Foods eaten in­clude: cad­dis­flies, moths, bee­tles, flies and leafhop­pers. (Bogan, M. A. and Valdez, E. W., De­cem­ber 14, 2000; Troues­sart, 1999)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects

Pre­da­tion

No preda­tors are known.

Ecosys­tem Roles

North­ern bats play an im­por­tant role in their ecosys­tem by eat­ing large quan­ti­ties of in­sects.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Due to its in­sec­tiv­o­rous feed­ing style, M. septen­tri­on­alis helps con­trol pop­u­la­tions of po­ten­tion­ally harm­ful in­sects. (Al­tring­ham, John D., 1996)

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

As is the case with most bats, many hu­mans con­sider north­ern bats to be pests. Bats often work their way into the at­tics of houses and may carry a threat of ra­bies, al­though this threat is often ex­ag­ger­ated. (Al­tring­ham, John D., 1996)

• Negative Impacts
• household pest

Con­ser­va­tion Sta­tus

Tim­ber har­vest­ing may in­ter­fere with these bats' abil­ity to uti­lize trees for nurs­ery colonies and day roosts. It also may prove detri­men­tal to their for­ag­ing habits in forested areas (Thomas, 1993). Use of chem­i­cal and bi­o­log­i­cal in­sec­ti­cides is an­other source of con­cern af­fect­ing their food sup­ply. A less vital, yet very real threat to M. septen­tri­on­alis is the dis­tur­bance they face in the caves (where recre­ational "cav­ing" is pop­u­lar) or mines (which are often closed after being aban­doned) where they hi­ber­nate. A so­lu­tion to the prob­lem of dis­tur­bance at hi­ber­nac­ula is to put up gates that per­mit the bats to pass while ex­clud­ing hu­mans. (Thomas, Don­ald W., 1993)

Tem­per­ate North Amer­i­can bats are now threat­ened by a fun­gal dis­ease called “white-nose syn­drome.” This dis­ease has dev­as­tated east­ern North Amer­i­can bat pop­u­la­tions at hi­ber­na­tion sites since 2007. The fun­gus, Ge­omyces de­struc­tans, grows best in cold, humid con­di­tions that are typ­i­cal of many bat hi­ber­nac­ula. The fun­gus grows on, and in some cases in­vades, the bod­ies of hi­ber­nat­ing bats and seems to re­sult in dis­tur­bance from hi­ber­na­tion, caus­ing a de­bil­i­tat­ing loss of im­por­tant meta­bolic re­sources and mass deaths. Mor­tal­ity rates at some hi­ber­na­tion sites have been as high as 90%. (Cryan, 2010; Na­tional Park Ser­vice, Wildlife Health Cen­ter, 2010)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Migratory Bird Act

  No special status

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Other Com­ments

My­otis septen­tri­on­alis was for­merly clas­si­fied as a mem­ber of the species keeni (Bar­clay et. al., 2000).

My­otis is a de­riv­a­tive of the Greek word for "mouse-eared" (Bar­clay et. al., 2000).

Septen­tri­on­alis comes from the Latin word for "north­ern". (Cac­eres and Bar­clay, May 12, 2000)

Con­trib­u­tors

Al­li­son Poor (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Jes­sica Ol­len­dorff (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, On­drej Pod­laha (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Al­tenbach, J. S., B., Har­vey, M. J.. 2001. "My­otis Septen­tri­on­alis (North­ern Long Eared Bat)" (On-line). Ac­cessed 10/06/01 at http://​talpa.​unm.​edu/​batcall/​accounts/​accountsbase/​myse.​html.

Al­tring­ham, John D., 1996. Bats Bi­ol­ogy and Be­hav­iour. New York: Ox­ford Uni­ver­sity Press.

Bat Con­ser­va­tion In­ter­na­tional, Inc, 2001. "Bat Species: U.S. Bats: My­otis Septen­tri­on­alis" (On-line). Ac­cessed 10/06/2001 at http://​batcon.​org/​discover/​species/​mysept.​html.

Bogan, M. A., N., Valdez, E. W.. De­cem­ber 14, 2000. "Texas Parks & Wildlife: Na­ture" (On-line). Ac­cessed 10/06/01 at http://​www.​tpwd.​state.​tx.​us/​nature/​wild/​mammals/​bats/​species/​north_​,my­otis/htm.

Cac­eres, C., R. Bar­clay. May 12, 2000. My­otis septen­tri­on­alis. Mam­malian Species, No. 634: pp. 1-4.

Cryan, P. 2010. "White-nose syn­drome threat­ens the sur­vival of hi­ber­nat­ing bats in North Amer­ica" (On-line). U.S. Ge­o­log­i­cal Sur­vey, Fort Collins Sci­ence Cen­ter. Ac­cessed Sep­tem­ber 16, 2010 at http://​www.​fort.​usgs.​gov/​WNS/​.

Na­tional Park Ser­vice, Wildlife Health Cen­ter, 2010. "White-nose syn­drome" (On-line). Na­tional Park Ser­vice, Wildlife Health. Ac­cessed Sep­tem­ber 16, 2010 at http://​www.​nature.​nps.​gov/​biology/​wildlifehealth/​White_​Nose_​Syndrome.​cfm.

Ruff, Sue., W. 1999. The Smith­son­ian Book of North Amer­i­can Mam­mals. Wash­ing­ton and Lon­don: Smith­son­ian In­sti­tu­tion Press.

Texas Tech­ni­cal Uni­ver­sity, 1997. "The Mam­mals of Texas - On­line Edi­tion: North­ern My­otis" (On-line). Ac­cessed 10/05/01 at http://​www.​nsrl.​ttu.​edu/​tmot1/​myotsept.​htm.

Thomas, Don­ald W., 1993. "Bats, Mines, and Pol­i­tics. BATS. Vol 11, No 2: 10-11" (On-line). Ac­cessed 10/06/01 at http://​www.​batcon.​org/​batsmag/​v11n2-3.​html.

Troues­sart, 1999. "Liv­ing Land­scapes: En­dan­gered Species and Spaces" (On-line). Ac­cessed 10/05/2001 at http://​www.​livinglandscapes.​org/​endangered/​Mammals/​northern1.​htm.