The largest and most widespread bat in North America — a tree-roosting bat with frosted gray-and-brown fur. Migrates long distances annually; tragically suffers extremely high mortality at wind turbines.

Also called: Hoary

Native status: Native; under emergency review due to wind turbine mortality

§ Quick facts

SizeBody 13–15 cm (5–6 in); wingspan 34–42 cm
Weight20–35 g (0.7–1.2 oz) — largest US bat
LifespanWild typically 6–7 years
OrderChiroptera
FamilyVespertilionidae

§ Encyclopedia

The hoary bat is a species of bat in the vesper bat family, Vespertilionidae. It lives throughout most of North America.

Source: Wikipedia — Hoary bat Licensed under CC BY-SA 4.0

§ Identification

Field marks. Large bat with mahogany-brown fur frosted with silver-white tips (the "hoary" appearance); yellow throat; thick fur on tail membrane.

Similar species. Other Lasiurus tree bats (smaller, different coloring — Eastern Red Bat rusty-red; Silver-haired Bat dark with silver). Big Brown Bat (no frosted appearance).

Voice. Loud audible chirps (~12 kHz) — among the few US bats with calls within human hearing range.

§ Diet & behavior

Diet. Large moths (preferred), beetles, dragonflies, mosquitoes, occasional smaller bats.

Behavior. Largest bat in North America. Roosts solitarily in tree foliage rather than caves or buildings — making them less affected by white-nose syndrome but extraordinarily vulnerable to wind turbines. Estimated 800,000+ hoary bats killed annually by wind turbines in North America; turbine mortality may exceed reproductive capacity in some populations. Migratory; populations move between Canadian/northern US summer range and Mexican/Central American wintering grounds.

§ Range

Across most of North America (migratory)

§ Habitat

Roosts in trees; forages over open habitats

§ Threats

Wind turbine collisions (estimated millions of bat deaths annually), pesticide-driven insect declines, deforestation.

§ Conservation status

According to the IUCN Red List, the hoary bat is currently classified as Least Concern.

§ What helps

Support smart wind siting and curtailment during peak migration. Skip pesticides. Plant native trees.

Support our work More ways to help

§ Further reading

§ Sources cited

  • Bat Conservation International
  • American Wind Wildlife Institute
  • USGS National Wildlife Health Center
  • IUCN Red List 2018