Little Brown Myotis
Formerly named Little Brown Bat.
- True to its name, the little brown myotis weighs only 4-8 grams and is approximately 4-5 cm long.
- The overall colouration is brown and they are slightly buffy- gray underneath.
- The wings are tinged bluish-gray.
Habits and Reproduction
- They forage typically over water and their diet consists mainly of aquatic insects such as midges, mosquitoes, mayflies, and caddisflies.
- Three different roosting sites are used: day roosts, night roost and hibernation roosts.
- The little brown myotis leaves its roost at dusk and the next two or three hours are peak activity periods. They are also active before dawn.
- They typically produce only one pup each year. Little brown myotis start breeding after one year and have been recorded to live over 30 years.
- In summer, the males and females live apart while the females raise the young. When fall comes, both sexes fly south to a hibernaculum, where they mate and then hibernate.
- Little brown myotis use a wide variety of forest habitat and readily makes use of man-made structures.
- 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 200-400 km/yr. If the spread of WNS continues at the current rate, the entire Canadian population would likely be impacted within 11-22 years.
- Please report any unusual bat activity such as flying outside in daytime or deaths to the Ministry of the Environment, Conservation and Parks and Forestry at 800-667-1940.
- You can help reduce the spread. Do not enter non-commercial caves and abandoned mines where bats may be present.