Tri-coloured Bat

Tri-coloured Bat – Photo credit S. Dobbyn

Perimyotis subflavus

Note- Formerly called Eastern Pipistrelle


  • COSEWIC – Endangered
  • COSSARO – Endangered


  • They are easily distinguished from other similar species by their tri-colored fur– reddish, yellowish and brownish. The forearms are orange to red, and the wing membrane is black.
  • Adults weigh between 4 to 10 g and reach approximately 8 cm long.
  • They have a slow, undulating flight, which is often compared to that of a moth or butterfly.


  • Tri-coloured Bats hunt at the edges of forests, near streams or over open water and are among the first bats to emerge at dusk each night. They are thought to roost in foliage or in high tree cavities.
  • In autumn, Tri-coloured Bat engage in swarming near the entrances to hibernation sites. They are among the first bats to enter hibernation each fall and among the last to emerge in spring.. Hibernation sites are found deep within caves or mines. These bats have strong fidelity to their winter hibernation sites.


  • Pregnant females gather in small maternal colonies typically in tree cavities or foliage where they give birth to one or two pups per summer. Mating occurs mid-autumn.


  • They live in shrubby areas and open forests close to water.  They will sometimes be found close to the edge of urban areas. They are seldom found in buildings.


  • White-nose Syndrome (WNS) has led to catastrophic declines of bat populations in north-eastern North America.  WNS is caused by a fungus that likely originated in Europe. It grows in humid, cold environments, typical of caves where bats hibernate.
  • It was first identified in a cave near Albany, New York in 2006.  By 2010, WNS was confirmed in Ontario. The mortality rates at infected hibernation sites in Ontario, Quebec and New Brunswick are over 80%.
  • WNS is expanding in Canada at average rate range of 200-400km/yr. If the spread of WNS continues at the current rate, the entire Canadian population would likely be impacted within 11-22 years.

Click here for more information.

Conservation Actions:

  • Please report any unusual bat activity such as flying outside in daytime or deaths to the Ministry of Natural Resources at 800-667-1940.
  • You can help reduce the spread. Do not enter non-commercial caves and abandoned mines where bats may be present.