Myotis septentrionalis is a medium sized Myotis with long, rounded ears that extend beyond the tip of the nose when laid forward and a long, pinted tragus. The pelage typically is dull brown dorsally and pale brown ventrally. The wing membrane extends to the base of the toes, and the calcar is slightly keeled. The dental formula is incisors 2/3, canine 1/1, premolars 3/3, molars 3/3.
The bat with which the northern myotis is most apt to be confused is the little brown myotis. The northern myotis differs from that species by its longer ears, longer and more sharply pointed tragus, and less glossy appearing pelage.
This species occurs in the northeastern quarter of the United States and southern Canada west to Alberta and eastern British Columbia. Its distribution in Kansas is not well known and may be expanding. The species was not known to occur in Kansas until 1951, when individuals of the species were found hibernating in the gypsum mines in Marshall county. Before 1972, the species was known only from the vicinity of those mines. The status of the mines as a hibernaculum for the species is uncertain (see the account of Myotis lucifugus). In central Kansas, the northern myotis was regarded as a migrant that flew over the state in spring and autumn but did not breed here. Pregnant bats finally were discovered in north-central Kansas in the 1990s, and the species has become relatively common in riparian woodland in Phillips, Rooks, Graham, Osborne, Ellis, and Russell counties. The species conceivably will be found in other counties where riparian woodland provides opportunities for roosting. If the mines in Marshall County no longer serve as a hibernaculum, the species must migrate to another state to hibernate.
County Breakdown: County Name (# occurrences)
Ellis (36), Graham (1), Leavenworth (1), Marshall (62), Osborne (3), Phillips (1), Rooks (6), Russell (4), Washington (3)
Copulation occurs before the beginning of hibernation. Females store sperm in their uteri during hibernation, and ovulation does not occur until the bats emerge from hibernation in the spring. Actual gestation probably lasts about 50 to 60 days. In Kansas, a single young is born in June and the young are volant by the end of July.
The natural history of this species is poorly known. In winter, northern myotis typically hibernate in caves or mines, but no hibernacula have been found in Kansas other than the Marshall County mines. Nursery roostss typically are behind loose tree bark and much less commonly in old buildings. These bats are gleaners, which means they feed on insects picked off the ground or from vegetation. The bats presumably use their sukperior hearing to locate insects from the sounds they make by moving or fluttering their wings. Insects are carried to a perch and eaten there.
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. The diet consists of insects of the orders Homoptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, and Diptera plus spiders.
In general, these bats consume a variety of smaller night-flying insects, but they may sometimes glean sitting prey as well.
Predators and Defense:
There are no published accounts of predation on northern myotis. A dead northern myotis was found adjacent to a road in Hays, Kansas, presumably the result of a collision with an automobile.
Growth and Longevity:
Adults may attain the following dimensions: total length 86-99 mm, length of tail 36-43 mm, length of hind foot 8-10 mm, length of ear 16-18 mm, weight 5.2-8.4 g. No information is available on longevity in this species.
The taxonomic history of this species is complex. Bats now known as Myotis septentrionalis originally were named Vespertilio subulatus keenii. Later, it was discovered that Myotis subulatus and Myotis keenii were separate species, so these bats went by the name Myotis keenii. Myotis keenii subsequently was shown to consist of two species, the more widespread of the two being Myotis septentrionalis. The species is monotypic in that there are no subspecies.
I know of no publications relating to fossils of this species.
1967. Jones, J. K. Jr., E. D. Fleharty, and P. B. Dunnigan . The distributional status of bats in Kansas. Univ. Kansas Mus. Nat. Hist. Misc. Publ., 46:1-33. . . : pp. .
1979. Fitch, J. H., and K. A. Shump, Jr.. Myotis keenii. Mammalian Species. 121: pp. 1-3.
1999. Wilson, D. E., and S. Ruff. The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washsington, DC. Pp. 1-750.
2000. Sparks, D. W., and J. R. Choate. Distribution, natural history, conservation status, and biogeography of bats in Kansas. Pp. 173-228 in J. R. Choate, Reflections of a Naturalist: Papers Honoring Professor Eugene D. Fleharty. Fort Hays State University, Hays, KS.
2008. Timm, R. M., G. R. Pisani, J. R. Choate, N. A. Slade, G. A. Kaufman, and D. W. Kaufman. Mammals of Kansas. http://www.ku.edu/~mammals, Pp. .