Photo Credit: Merlin D. Tuttle, Bat Conservation International

SCIENTIFIC NAME: Myotis septentrionalis (Trouessart)

OTHER NAMES: Northern Myotis,  Keen’s Myotis.

STATUS: Poorly known. Found statewide, except southwestern region. The U.S. Fish and Wildlife Service listed the northern long-eared bat as threatened with an Interim 4(d) Rule in April of 2015. HIGH CONSERVATION CONCERN.

DESCRIPTION: Similar in appearance to other small (forearm length = 34.6-38.8 mm [1.4-1.5 in.], wingspan = 228-258 mm [8.9-10.1 in.]; weight ~ 5-10 g [0.2-0.4 ozs.]), light brown bats of the genus Myotis (Caceres and Barclay 2000). Differ from other Myotis by having longer ears that extend approximately four millimeters [0.2 inch] beyond nose and, a longer, more sharply pointed, tragus. No sexual dichromatism; however, females tend to be larger than males (Barbour and Davis 1969).

DISTRIBUTION: Throughout much of Canada and eastern United States, extending south through Alabama and Georgia and into northern Florida.  Distribution in Alabama poorly known. Small numbers have been observed from localities in the Bear Creek River System (Hilton and Best 2000) and Bankhead National Forest in northwestern Alabama. Likely occurs in other forested areas throughout the Piedmont and Cumberland Physiographic Regions.

HABITAT: Strongly associated with forested habitats. Tends to forage beneath forest canopy along ridges and hillsides. In winter, individuals hibernate in caves and abandoned mines, often with other species of bats. Easily overlooked in caves as this small bat often will roost in narrow crevices where they are not easily observed (Whitaker and Hamilton 1998). During summer months, females form small maternity colonies in hollow trees, under exfoliating bark, or in buildings. Isolated males can be found in caves year-round. In Alabama, has been captured in, and near, caves often associated with mature forests dominated by oak and eastern hemlock trees. May be found in similar habitats at higher elevations throughout northern Alabama.

FEEDING HABITS: Opportunistic feeders, consuming a variety of prey. Reported to consume insects from Orders Lepidoptera, Neuroptera, Hemiptera, Homoptera, Diptera, Coleoptera, Trichoptera, Ephemeroptera, and Hymen-optera.

LIFE HISTORY AND ECOLOGY: Often observed swarming in the entrances of caves or mines prior to hibernation, usually in August or September. Mating occurs at this time. Usually hibernates in small groups or roosts singly in narrow crevices. After hibernating, females emerge and often form small maternity colonies of up to 100 individuals in nearby trees. Roost trees often found in close proximity, allowing females to choose among a variety of roosting conditions. Males and nonreproductive females usually roost singly, or form small colonies. Have a single young in May or June in southern portions of  distribution.

Parturition can be delayed until July at more northern latitudes. Volant young have been observed as early as July.  Short, wide wings and longer tail membranes enable them to fly at slow speeds through more cluttered habitats. These characteristics in addition to having long ears indicate species may glean insects from vegetation. These adaptations likely allow them to capture aerial as well as stationary prey in forested habitats.

BASIS FOR STATUS CLASSIFICATION: Status and distribution in Alabama unknown. Recent captures in northwestern Alabama indicate species may be fairly common in portions of its  distribution. However, overall lack of records in the state suggests an irregular distribution throughout Alabama.

Author: Travis Hill Henry