Bats and White Nose Syndrome

Bats in Ontario


As with all wildlife, bats are an important part of Ontario’s biodiversity.  Eight different species of bats are found in this province, with Little Brown Bats and Big Brown Bats being the most common.  Learn more.


Bats are the primary predator of night-flying insects such as moths and mosquitoes.  A single bat can eat three times its body weight in insects every night.


Bats are wild animals, and like all wildlife, should be left alone.  Bats may carry a number of diseases.  A small number carry rabies.  Learn more.


White Nose Syndrome


Ontario bat with White Nose Syndrome

Bat exhibiting white nose syndrome. Photo credit: New York Department of Environmental Conservation.




The condition has been dubbed "white nose syndrome" because some affected bats have visible rings of white fungus around their faces.  The cause of the syndrome is believed to be Geomyces destructans, a fungus that grows in the skin of the bat, producing a white, fuzzy appearance on the muzzle, wings and ears. Infected bats emerge from torpor (the state of low physical activity characteristic of hibernating animals) more frequently than normal during winter hibernation, exhausting their energy reserves before food becomes available in the spring.


White nose syndrome has killed more than five million bats in the northeastern U.S.  It was first identified in a cave near Albany, New York, in 2006. Cases have also been found in more than a dozen American states as well as Quebec, New Brunswick and Nova Scotia.


In March 2010, white nose syndrome was confirmed for the first time in Ontario.




Map of North America showing the spread of White Nose Syndrome since 2006


This map shows how white nose syndrome has spread since it was discovered in New York State in 2006.  In 2010, it was discovered in Canada for the first time, in both Ontario and Quebec. In 2011, it was detected in New Brunswick and Nova Scotia. The areas highlighted indicate general locations and not necessarily the extent of the syndrome.




White nose syndrome is not thought to be a human health issue.  The syndrome has been circulating through caves in the northeastern United States for at least six years.  Some of these caves have been visited by thousands of people and no illnesses have been reported.


A fact sheet about the syndrome is available at the bottom of this page. 


Monitoring for White Nose Syndrome


From late fall to spring, the ministry monitors bat hibernation sites for any signs of the syndrome in the province. 


The ministry encourages you to report any unusual bat activity (flying outside in the daytime) or deaths to the Canadian Cooperative Wildlife Health Centre at 1-866-673-4781 or the Natural Resources Information Centre at 1-800-667-1940 (TTY for the hearing impaired at 1-866-686-6072).


Reducing the Spread of White Nose Syndrome in Ontario


The ministry is concerned about the potential impact of white nose syndrome on Ontario's bat populations.  Although the condition is not well understood, it is believed that human activity in caves is contributing to its spread.


Ministry staff are working with researchers, wildlife rehabilitators and the caving community to promote practices that may reduce the risk of spreading the syndrome. This includes disinfecting clothes and equipment after being in a cave and by not using the same equipment at different sites. Individuals who spend time in caves in the northeastern United States and Canada are asked not to use the same equipment in Ontario.


Through the development of white nose syndrome response strategies the ministry is also working closely with other jurisdictions, including neighbouring states, Quebec and the United States Fish and Wildlife Service, to ensure a coordinated approach to monitoring and prevention.


We urge the public to refrain from entering non-commercial caves and abandoned mines where bats may be present.  We are also asking Ontarians to refrain from entering any caves or abandoned mines in the United States or Canada where white nose syndrome has been identified. 


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