Northern long-eared bat (Myotis septentrionalis)
|Also known as:||Northern myotis|
|Size||Length: 7.6 - 9.5 cm (2)|
|Weight||2 - 8 g (2)|
The northern long-eared bat is classified as Least Concern (LC) on the IUCN Red List (1).
Distinguished by the long, rounded ears for which it is named (2) (3), the northern long-eared bat (Myotis septentrionalis) is a small bat species of the genus Myotis, which means ‘mouse-ear’ in Greek (2). The distinctive ears, when laid forward, are so long that they extend past the tip of the nose (2) (3).
The northern long-eared bat has a brown-to-reddish coat, which is yellowish-grey on the belly (2) (3). The ears and face are usually blackish (3). The female northern long-eared bat is usually larger and heavier than the male (2).
The northern long-eared bat occurs in Canada and most U.S. states east of the Mississippi River, ranging west to British Colombia, Montana and Wyoming (1). The northern long-eared bat’s range extends south to Alabama, Georgia and Florida (1) (3). The northern long-eared bat is most abundant in the northern parts of its large range (4) (5).
Generally associated with boreal forests and the wet forests of British Columbia, the northern long-eared bat relies on dense areas of forest for maternity and day roosts (1)(5).During the day, this species may roost in cavities in trees or in crevices under loose bark (1) (4). It may also roost in buildings and other man-made structures (1) (2) (4)
In the winter, the northern long-eared bat takes refuge in caves and abandoned mines (1) (2) (4) (5).
The northern long-eared bat is known to forage along forest edges, on hillsides and ridges, in clearings, canopies, and over water (1) (2) (5). A generalist predator, the northern long-eared bat takes its prey opportunistically using echolocation (1) (4). It typically catches its prey during flight (1) (2), and feeds on a variety of insects, including moths, beetles, flies, caddisflies and spiders (2). This species is most active one or two hours after sunset, and again before sunrise (2) (4).
Generally a solitary species, the northern long-eared bat is rarely seen in large groups (5). Interestingly, male and female northern long-eared bats will always roost separately, however; this species may sometimes roost with other bat species (1). The northern long-eared bat hibernates in small groups in caves and abandoned mines from late autumn to early spring (4).
Mating occurs in large congregations, or swarms, outside caves and abandoned mines prior to hibernation (2) (4). The female stores the sperm through hibernation and begins ovulation when it emerges in the spring (4). Small maternity colonies are formed by groups of female northern long-eared bat during the breeding season, where up to 60 females may be present in a colony (1) (2). Each female gives birth to a single pup around two months after the spring emergence (4).
The northern long-eared bat faces a number of threats across its range. Timber harvesting may reduce available trees for roosting, as well as available forest for foraging, while the continued use of insecticides contaminates this species’ food supply (1). Additionally, the northern long-eared bat is affected by white-nose syndrome, a deadly fungus, but the extent to which this fungus is a threat is not yet known (5).
A growing threat to this species is human disturbance in caves and at other roosting locations (1) (4). The closure of mines throughout its range may also have an adverse effect on this species, by reducing the availability of suitable hibernation sites (4).
The declining number of undisturbed caves for hibernation is perhaps a growing concern for the northern long-eared bat, and therefore protection of caves within this species’ range is becoming increasingly important. In particular, it is important for caves to be gated, rather than closed, to ensure the survival of this species (4). Gates that prevent intrusion to caves and mines by people, but allow bats to enter, have been installed in some caves in West Virginia, Pennsylvania, and Illinois (4).
The northern long-eared bat is listed as a Species of Special Concern in North Carolina, giving it some legal protection (4). The northern long-eared bat also occurs in several protected areas across its range (1) (4). Otherwise, the only legal protection afforded to this species is the Federal Cave Protection Act, which regulates cave usages and removal of cave resources, and indirect protection through other cave-dwelling species’ protection plans (4).
Find out more about the northern long-eared bat:
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- Boreal forest: the sub-Arctic forest of the high northern latitudes that surrounds the North Pole and is mainly composed of coniferous trees.
- Echolocation: detecting objects by reflected sound. Used by bats and odontocete cetaceans (toothed whales, dolphins and porpoises) for orientation and to detect and locate prey.
- Hibernation: a winter survival strategy in which an animal’s metabolic rate slows down and a state of deep sleep is attained. While hibernating, animals survive on stored reserves of fat that they have accumulated in summer.
- Ovulation: in female mammals, the release of a ripe egg from an ovary (one of the paired reproductive organs).
IUCN Red List (May, 2011)
- Schwartz, C.W. and Schwartz, E.R. (2001) The Wild Mammals of Missouri. University of Missouri Press, Missouri.
- Hamilton, W.J. and Whitaker, J.O. (1998) Mammal of the Eastern United States. Cornell University Press, Ithaca, New York.
NatureServe Explorer - Northern long-eared bat (Myotis septentrionalis) (May, 2011)
Bat Conservation International - Northern long-eared bat (Myotis septentrionalis) (May, 2011)