Bats of Ontario Part 2: The Resident Species #WingedWednesdays

By: Bridget Sparrow-Scinocca

This week we will focus on introducing the 5 non-migratory species of bats that live in Ontario. These bats spend their summers foraging here in Ontario, where they give birth to and raise their young. They then move on to hibernate over the winter months around Ontario, and emerge as the weather warms in late spring or early summer.

Four of these species are currently listed as endangered in Ontario. Current threats to these species include habitat loss and the increasing development of wind turbines. However, White Nose Syndrome (WNS), which was accidentally introduced to North America in 2006, has been the main reason for the recent devastation of Ontario bat populations. This fungus affects bats in their winter hibernacula, causing them to wake up repeatedly, depleting their energy stores and causing mass die-offs.  Bats reproduce slowly which means that once their populations are lowered due to external threats it can be very hard for these species to recover.

Let’s meet our 5 spectacular resident species: the big brown bat, the little brown myotis, the northern myotis, the eastern small-footed myotis and the tri-colored bat.

Big Brown Bat

Scientific Name: Eptesicus fuscus

Description: Their bodies are covered with light brown fur (1). Their wing membrane, tail membrane, muzzle and ears are black in colour.

Size: Their name is somewhat deceiving, as big brown bats only range in weight from approximately 11 to 25g (or equal to the weight of 3-5 toonies!). Their body length, from the tip of their nose to the end of their tail, is approximately 9 to 14 cm. A big brown bat’s wingspan is 32 to 35 cm on average (1)(3). Female bats are on average larger than their male counterparts.

Distribution and Habitat: Big brown bats can be found across southern Canada and as far south as Venezuela and Columbia. They can be found near large areas of deciduous forest. However, big brown bats have adapted to living near humans quite well. They can typically be found roosting in buildings such as barns, houses and churches (2). This is the most common bat found in Toronto.

Diet: Big brown bats are insectivorous. The strength of their skull structure and jaws allows them to prey primarily on beetles which have hard exoskeletons (2). They also eat dragonflies, wasps, flying ants and moths.

Behaviour: During the summer, when female big brown bats are raising their young, they live in large maternity groups.  Male big brown bats live alone or in small groups during this period. During the winter big brown bats move to their winter hibernacula in man-made or natural environments. Big brown bats can withstand hibernating colder temperatures, meaning that they can survive conditions that other bats cannot (2).

Status: They are currently listed as Least Concern on the ICUN red list.

Little Brown Bat  

Scientific Name: Myotis lucifugus

Description: Their bodies are covered with shiny brown fur (3). Their wing membrane, tail membrane, muzzle and ears are dark brown or black in colour. They are smaller in size in comparison to big brown bats and have distinguishing characteristics that separate them from other myotis species.  This species can live as long as 40 years!

Size: Little brown bats range in weight from approximately 4 to 11g (or equal to the weight of 1-2 toonies!). Their body length, from the tip of their nose to the end of their tail, is approximately 4 to 5 cm. A little brown bat’s wingspan is 22 to 27 cm on average (3)(4).

Distribution and Habitat: Little brown bats can be found across southern Canada and the United States. They can be found in Alaska and in regions of forested high elevations in Mexico (5). They used to be Canada’s most common species of bat until their populations were reduced by 90% due to WNS (6).

Diet: Little brown bats are insectivorous. They typically feed on swarming aquatic insects such as midges and mayflies. However, they will feed on other insects such as moths and beetles if that is what is available.

Behaviour: Little brown bats are most active a few hours after dusk. They roost together during the summer in tree cavities, loose bark or abandoned buildings. During the winter months they move to their winter hibernacula in caves or abandoned buildings. Before white-nosed fungus devastated populations of little brown bats, they could be found in winter colonies numbering in the thousands (6).

Status: They are currently listed as “Endangered” in Ontario.  This means “the species lives in the wild in Ontario but is facing imminent extinction or extirpation” – Government of Ontario (6).

Northern Myotis  

Scientific Name: Myotis septentrionalis

Description: Their head and backs are covered with yellowish-brown fur (7).  Their bellies are covered in a paler coloured fur that is more grey in tone than the rest of their bodies. They are small in size and can be distinguished from little brown bats by their characteristic long rounded ears and shape of their long pointed tragus.   

Size: Northern myotis range in weight from approximately 6 to 9g (or equal to the weight of 1-2 toonies!). Their body length, from the tip of their nose to the end of their tail, is approximately 7.8 cm. A northern bat’s wingspan is 23 to 26 cm on average (7).

Distribution and Habitat: Northern myotis are found in every Canadian province and two Canadian territories! They can also be found across the United States. Old-growth mature forests with hilltops and ridges are the preferred habitat of northern myotis (7)(8).

Diet: Northern myotis are insectivorous. They feed on a variety of insects such as flies, moths, beetles and caddisflies. Their long ears allow them to listen to and locate prey crawling on foliage. This allows them to forage by plucking insects off of a solid surface.

Behaviour: Northern myotis are active shortly after sunset when they begin to forage. They roost during the summer in tree cavities, loose bark or abandoned buildings (7)(8). During the winter months they head to their winter hibernacula in caves or abandoned mines.

Status: They are currently listed as “Endangered” in Ontario.  This means “the species lives in the wild in Ontario but is facing imminent extinction or extirpation” – Government of Ontario (8).

Eastern small-footed myotis

Scientific Name: Myotis leibii

Description: Their head and backs are covered with light brown fur (9).  Their bellies are covered in a greyish-brown fur. They have a distinctive black mask across their face, as well as black ears and wings.

Size: Eastern small-footed bats range in weight from approximately 4 to 5 g (or equal to the weight of a nickel). Their body length, from the tip of their nose to the end of their tail, is approximately 8 cm. Their wingspan is 21 to 25 cm on average (9)(10). As their name suggests these bats have small feet in relation to other closely related species, measuring on average only 7 mm long.

Distribution and Habitat: Eastern small-footed myotis can be found in eastern Canada and the United States. During the warmer season when they are most active, they can be found in tree and rock crevices, bridges, buildings and nestled in rocky outcrops (9)(10).  

Diet: Eastern small-footed myotis are insectivorous. They mainly feed on mosquitoes, beetles, moths and flies.

Behaviour: Eastern small-footed bats are active shortly after sunset, when they begin to forage. They switch roosts daily, and therefore need to live in areas with an abundant level of roosting sites. During the winter months they move to their winter hibernacula (9)(10). Eastern small-footed bats hibernate horizontally. This allows them to tuck in to cracks and crevices in caves to hibernate, often alone.

Status: They are currently listed as “Endangered” in Ontario.  This means “the species lives in the wild in Ontario but is facing imminent extinction or extirpation” – Government of Ontario (9).

Tri-colored Bat

Scientific Name: Perimyotis subflavus

Description: Tri-coloured bats are known for the distinctive strands of hair on their back which are yellow, black and brown in colour (11).  Overall, they appear to have pale brown fur. The wings and sides of their bodies are dark brown. Their forearms, ears and muzzle are a reddish-orange colour, as seen in the picture above.

Size: A tri-coloured bat weighs on average 7 g (or equal to the weight of a toonie). Their body length, from the tip of their nose to the end of their tail, is approximately 8 cm. Their wingspan is on average 23 cm (11)(12).

Distribution and Habitat: Tri-coloured bats are found at the northernmost point of their range in southeastern Canada all the way through the United States to their southernmost point in Central America. Similar to the eastern small-footed bat they can be found in rock crevices, squirrel nests, caves and buildings near water (11)(12)(13). 

Diet: Tri-coloured bats are insectivorous. Studies show they eat many different types of insects throughout their range. They can glean spiders from their webs, and also eat many other types of flying insects.

Behaviour: Tri-coloured bats typically forage over water. In the summer they can be found forming day roosts or maternity colonies in trees, and sometimes man-made structures. They will then exhibit a swarming behaviour near a cave where they will hibernate individually for the winter (11).

Status: They are currently listed as “Endangered” in Ontario.  This means “the species lives in the wild in Ontario but is facing imminent extinction or extirpation” – Government of Ontario (12).

References

Big Brown Bats

(1) “Big Brown Bat” (On-line), Nature Conservancy Canada. Accessed August 08, 2021 at https://www.natureconservancy.ca/en/what-we-do/resource-centre/featured-species/mammals/big-brown-bat.html

(2) Mulheisen, M. and K. Berry 2000. “Eptesicus fuscus” (On-line), Animal Diversity Web. Accessed August 08, 2021 at https://animaldiversity.org/accounts/Eptesicus_fuscus/

Little Brown Bat

(3) Havens, A. 2006. “Myotis lucifugus” (On-line), Animal Diversity Web. Accessed August 11, 2021 at https://animaldiversity.org/accounts/Myotis_lucifugus

(4) “Little Brown Bat” (On-line), Nature Conservancy Canada. Accessed August 08, 2021 at https://www.natureconservancy.ca/en/what-we-do/resource-centre/featured-species/mammals/big-brown-bat.html

(5) “Meet the Little Brown Bat” (On-line), Bat Conservation International. Accessed August 08, 2021 at https://www.batcon.org/meet-the-little-brown-bat/

(6) “Little Brown Bat” (On-line), Ontario Government. Accessed August 08, 2021 at https://www.ontario.ca/page/little-brown-myotis

Northern Long Eared Myotis

(7) Ollendorff, J. 2002. “Myotis septentrionalis” (On-line), Animal Diversity Web. Accessed August 11, 2021 at https://animaldiversity.org/accounts/Myotis_septentrionalis/

(8) “Northern Myotis” (On-line), Ontario Government. Accessed August 08, 2021 at https://www.ontario.ca/page/northern-myotis

Eastern small-footed Myotis

(9) “Eastern small-footed myotis” (On-line), Ontario Government. Accessed August 08, 2021 at https://www.ontario.ca/page/eastern-small-footed-myotis

(10) Scott, V. 2014. “Myotis leibii” (On-line), Animal Diversity Web. Accessed August 11, 2021 at https://animaldiversity.org/accounts/Myotis_leibii/

Tri-coloured Bat

(11) Hamlin, M. 2004. “Pipistrellus subflavus” (On-line), Animal Diversity Web. Accessed August 11, 2021 at https://animaldiversity.org/accounts/Pipistrellus_subflavus/

(12) “Tri-coloured Bat” (On-line), Bat Conservation International. Accessed August 08, 2021 at https://www.batcon.org/article/tri-colored-bat/

(13) “Tri-coloured Bat” (On-line), Ontario Government. Accessed August 08, 2021 at https://www.ontario.ca/page/tri-colored-bat