Bats of Ontario Part 1: Migratory Species #WingedWednesdays

By: Bridget Sparrow-Scinocca

Over the next two weeks our blog will focus on introducing the 8 native bat species in Ontario. This week we will focus on the 3 migratory species of bats. These 3 bats spend their summers here in Canada, where they give birth to and raise their young. They do not hibernate in caves, but instead fly south, migrating during the fall to spend the winter months in warmer habitats. Let’s meet our 3 incredible migratory species: the Hoary Bat, the Eastern Red Bat and the Silver-haired Bat.

Hoary Bat

Scientific Name: Lasiurus cinereus

Description: These bats are known for the beautiful colouration of their fur, which covers their backs and extends over their tail membranes as well as partially on the underside of their wings. It is greyish brown in colour, with characteristic white frosted tips (1)(3). Hoary itself means “greyish-white” and that is how this species got its name. They also have a distinctive yellow patch of fur under their neck (1)(3).

Size: Hoary bats are the largest bat species in Canada. They range in weight from approximately 18 to 39 g (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 13 to 15 cm. A hoary bat’s wingspan is 43 cm on average (1)(3).

Distribution and Habitat: Hoary bats spend their summers in the northernmost part of their range, which occurs from the treeline of Northern Canada across the top of the United States. During the summer months they typically live in trees (1)(3). They begin their migration during the month of October and usually fly south to warmer habitats in Southern California, Florida and Central America. Hoary bats are the only species of bats found in Hawaii. Stray migrant hoary bats have been found, deceased, as far away as Iceland and Scotland (4)!

Diet: Hoary bats are insectivorous. Moths are believed to make up the majority of their diet, but they also eat dragonflies, small wasps, beetles, grasshoppers and termites (1)(3).

Behaviour: Hoary bats are a solitary species. This means that they roost alone during the day in trees high off the ground. They are typically active 4 to 5 hours after dark and fly high and fast during feeding, making them a particularly hard species to catch and monitor (1)(3).

Status: They are currently listed as Least Concern on the ICUN red list. However, recent studies have shown that a significant increase in wind turbines is devastating populations of hoary bats across North America (2).  

Eastern Red Bat

Scientific Name: Lasiurus borealis

Description: These bats have distinctive thick red fur, which covers their backs and extends over their tail membranes, allowing them to camouflage well in their environment (5). Female bats of this species have more white frosting on the tips of their fur than their male counter parts (6).

Size: Eastern red bats are considered a medium-sized bat species. They range in weight from approximately 7 to 13 g (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 9 to 12 cm. An eastern red bat’s wingspan is 29 to 33 cm on average (5).

Distribution and Habitat: Eastern red bats spend their summers in the northernmost part of their range, in southeastern Canada. During the summer months they roost in trees, preferring to camouflage in dense leaf litter (6). They begin their migration south during the month of October, and typically fly to warmer habitats in the southeastern United States and northeastern Mexico (6).

Diet: Eastern red bats are insectivorous. They are known to eat many different types of insects such as moths, ants, flies, beetles and grasshoppers (5).  

Behaviour: Eastern red bats are a solitary species. This means that they roost alone during the day in trees with dense leaf coverage. They exit their roosts to feed at dusk and typically can be seen feeding on insects around a light source (5). These bats have one litter per year of approximately 3 to 4 young! Each offspring weighs approximately 30 % of their mother’s bodyweight. This means that an eastern red bat mother with 3 pups is carrying almost her fully body weight in babies (5) (6)!  As temperatures drop, red bats have been known to temporarily hibernate in leaf litter to keep warm before continuing on to their final migration.

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

Silver Haired Bat

Scientific Name: Lasionycteris noctivagans

Description: These bats have dark black fur with distinctive silver frosted tips on the back and underside of their bodies.

Size: Silver-haired bats range in weight from approximately 8 to 11 g (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 9.2 to 11.5 cm. A silver-haired bat’s wingspan is 29.5 cm on average (7).

Distribution and Habitat: Silver-haired bats spend their summers in the northernmost part of their range, in southern Canada and the northern United States (7). During the summer months they roost in trees. Studies have shown that silver-haired bats begin their migration travelling large distances, before heading south to their warmer over-winter habitat in the southern United States and northern Mexico (8).

Diet: Silver-haired bats are insectivorous. Studies have shown that their diet consists mainly of moths, but they will also eat flies and beetles (7).

Behaviour: Silver-haired bats are a solitary species, except for when they swarm during mating season. They roost in trees during the day, in tree cavities or under loose bark. They have also been found roosting in people’s backyard wood piles (8). It is believed that they forage most commonly around sunset and dawn in order to avoid foraging with other bat species which are faster fliers (7)(8).

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

References

Hoary Bat

(1) Anderson, SK. 2021. “Hoary Bat” (On-line), Kids Inquiry of Diverse Species. Accessed August 04, 2021 at http://www.biokids.umich.edu/critters/Lasiurus_cinereus/

(2) Frick, W.F., et al. 2017. “Fatalities at wind turbines may threaten population viability of a migratory bat”. Biological Conservation.  Accessed August 04, 2021 at http://dx.doi.org/10.1016/j.biocon.2017.02.023.

(3) Kopsco, H. and M. Hall. 2014. “Hoary Bat” (On-line), New Jersey Endangered and Threatened Species Field Guide. Accessed August 04, 2021 at http://www.conservewildlifenj.org/species/fieldguide/view/Lasiurus%20cinereus/

 (4)Tuttle, M. D. “The Little-Known World of Hoary Bats” (On-line), Bat Conservation International, Vol 13 Issue 4. Accessed August 04, 2021 at https://www.batcon.org/article/the-little-known-world-of-hoary-bats/.

Eastern Red Bat

 (5) Myers, P. and J. Hatchett 2000. “Lasiurus borealis” (On-line), Animal Diversity Web. Accessed August 04, 2021 at https://animaldiversity.org/accounts/Lasiurus_borealis/

 (6) “Lasiurus borealis” (On-line), Bat Conservation International. Accessed August 04, 2021 at https://www.batcon.org/bat/lasiurus-borealis/

Silver-haired Bat

(7) Bentley, J. 2017. “Lasionycteris noctivagans” (On-line), Animal Diversity Web. Accessed August 04, 2021 at https://animaldiversity.org/accounts/Lasionycteris_noctivagans/

 (8) “Lasionycteris noctivagans” (On-line), Bat Conservation International. Accessed August 04, 2021 at https://www.batcon.org/bat/lasionycteris-noctivagans/