A small bat with relatively long ears. Federally endangered due to white-nose syndrome (~90% decline).

Also called: Northern Myotis, Northern Bat

Native status: Native; federally endangered (2022)

§ Quick facts

SizeBody 8–9.5 cm (3.1–3.7 in); wingspan 23–27 cm
Weight5–9 g
LifespanWild typically 5–10 years; oldest documented 19
OrderChiroptera
FamilyVespertilionidae

§ Encyclopedia

Myotis septentrionalis, known as the northern long-eared bat or northern myotis, is a species of bat native to North America. There are no recognized subspecies. The northern long-eared bat is about 3–3.7 inches in length, with a wingspan of 9–10 inches. It is distinguishable by its long ears when comparing it to other bats in its genus. This species is commonly found in the northern United States and Southern Canada east of British Columbia. The geographic range includes 37 states.

Source: Wikipedia — Myotis septentrionalis Licensed under CC BY-SA 4.0

§ Identification

Field marks. Small brown bat with notably long ears (~17 mm) and a long pointed tragus (ear flap). Often distinguished from Little Brown Bat in hand by tragus shape.

Similar species. Little Brown Bat (shorter tragus, round ears). Indiana Bat (keeled calcar). Big Brown Bat (much larger).

Voice. Ultrasonic echolocation calls 40–80 kHz.

§ Diet & behavior

Diet. Moths, flies, beetles, spiders, leafhoppers. Distinctive long ears used for fine-detail echolocation that can locate stationary prey on leaves and bark.

Behavior. Among the species hardest hit by white-nose syndrome — populations have declined 97–100% in white-nose-affected hibernacula. Federally reclassified from threatened to endangered in 2022. Summers in mature forests with abundant snags for roosting; winters in caves and mines at 35–45°F.

§ Range

Eastern North America

§ Habitat

Mature deciduous forests

§ Threats

White-nose syndrome devastating populations, wind turbine strikes.

§ Conservation status

According to the IUCN Red List, the northern long-eared bat is currently classified as Endangered.

§ What helps

Support white-nose research. Don't enter bat caves.

Support our work More ways to help

§ Further reading

§ Sources cited

  • USFWS Northern Long-eared Bat Recovery
  • USGS National Wildlife Health Center
  • Bat Conservation International
  • IUCN Red List 2018