Archives > June 2018

Going Batty – The Little Brown Bat

The little brown bat, or Myotis lucifugus is the most common bat in Alberta. Aptly named for its size and colour, the little brown bat weighs approximately 8.5 grams and is light brown to reddish or dark brown in colour. Their ears and wings are dark brown to black, and their wings generally lack fur. Their wingspan is between 25 and 27 centimeters, with females being moderately larger than males.

The little brown bat is a true flying mammal that relies on echolocation to obtain information about its location as well as to find its food. The bats’ echolocation calls have a very high frequency and cannot be heard by people. When not searching for food, little brown bats make echolocation calls at about 20 calls per second, but when hunting, they can give out as many as ten times more calls per second. Little brown bats eat a large variety of small, flying insects. They normally eat mosquitoes, mayflies, moths, flies, beetles and midges but will feed on whatever type of insect is available. The bats normally go out on two feeding expeditions a night, once at sunset and then again before sunrise. In between feedings the bats rest and digest their food before heading out again. Suckling females can consume up to their weight in insects each night. In general most little brown bats ingest about 1000 insects per night, which is approximately half their body weight!

Little brown bats hibernate in the winter. They prefer cool, dark, humid places where the air does not move. Bats come out of hibernation in the spring when the temperature goes up and insects are emerging. This could be as early as April or as late as May. The bats’ summer roost commonly includes attics, rafters, under siding and barn hay lofts but they also use places like hollow tree trunks and bat houses.

Unfortunately, little brown bats are at real risk of contracting White Nose Syndrome disease, a destructive disease that grows in caves where bats hibernate. White Nose Syndrome is a fungus that was likely brought to Canada by cave explorers or spelunkers who may have carried dirt from European caves on their gear. This disease causes a fluffy white fungus to grow on the bat’s nose, wings and other bare skin during hibernation. The growth on the nose causes the bats to wake from hibernation due to dehydration as well as possibly to groom the fungus off.  This repeated waking drains the bat’s fat reserves, causing them to starve during hibernation.

At present the fungus is in Eastern North America but may work its way to the west. Researchers believe that European bats have developed an immunity to the disease but as little brown bats have not been exposed to the virus they have not developed an immunity to it.

Although some people are afraid of bats and think they are spooky and scary, little brown bats are very beneficial to humans. They help people to enjoy the outdoors more by devouring large quantities of pest insects. This may even further help humans by limiting the spread of diseases and reducing the need for pesticides. Little brown bats have their place in nature, just as any other creature does!

By Linda J. Schlegel

Sources:

http://aep.alberta.ca/fish-wildlife/wild-species/mammals/bats/little-brown-bat.aspx

http://edmontonjournal.com/news/local-news/going-to-bat-for-bats-a-new-community-program-aims-to-turn-homeowners-into-citizen-scientists

https://albertaep.wordpress.com/2015/10/29/albertas-happy-hibernators-bats/

http://www.hww.ca/en/wildlife/mammals/little-brown-bat.html

 

Alberta Wildlife Recoveries: Ord’s Kangaroo Rat

What are Ord’s kangaroo rats?

Ord’s kangaroo rat (Dipodomys ordii) is a subspecies of kangaroo rat native to western North America, including parts of southern Alberta and central Mexico (Patton 2005).

Kangaroo rats have elongated tails with bushy tips, and belong to the family Heteromyidae (kangaroo rats and mice). They derive their name from the elongated hind legs and powerful feet that produce their jumping movement, not dissimilar to the kangaroos they are named for.

Ord’s kangaroo rats can be identified by their orange-brown colouration, five-toed feet and reduced forelimbs (Recovery Plan 2013-2018). They have been listed as “threatened” under the Alberta Endangered Species Act, and it is illegal to harm or disturb the species or its habitat.

Where are Ord’s kangaroo rat found?

Ord’s kangaroo rat, like other species of kangaroo rat, are highly adapted for survival in arid, sparse, or shrubland habitats. Spending most of the daytime inside their burrows, they emerge at night to look for food and/or mates (AEP). In Southern Alberta, Ord’s kangaroo rat is distributed mainly in the area between the Red Deer and the South Saskatchewan Rivers (Recovery Plan 2013-2018).

According to the Alberta Ord’s Kangaroo Rat Recovery Plan (2013-2018), it is not currently clear as to whether the kangaroo rat population of southern Alberta have contact with that of the southern Saskatchewan population, just that they are separated from the Montana population by several hundred kilometers (COSEWIC 2006).

Population modelling of the kangaroo rats of southern Alberta has proved difficult, due in part to the fluctuating nature of the population (Recovery Plan). It has been theorised that increased human activity and the past few years of extended severe winters and spring flooding events has had a large impact on their survival.

What is being done to protect Ord’s kangaroo rat and why?

The Alberta Ord’s Kangaroo Rat Recovery Plan for 2013-2018 was created with the goals of “ensuring a natural, self-sustaining population resistant to the risk of extinction in the province”. To achieve this, the recovery plan focuses on “reducing the negative effects of human land uses on population size and fluctuations; conserving and enhancing the quality of open-sand habitats; and educational outreach to highlight the importance of the species”.

As the only species of Dipodomys in Alberta, Ord’s kangaroo rats are an essential part of the sand dune ecosystem, by “exerting substantial effects on the plant communities, soils, and predators” of the region (COSEWIC). They are also a focal point of conservation of the prairie sand dunes, rare and declining habitats that other endangered species and biodiversity depend on (COSEWIC; Finnamore & Buckle 1999).

What more needs to be done, and how can we help?

As is always the case with threatened or endangered species, improving knowledge in the wider public is vital to the success of species at risk recovery plans. This can be achieved via public education and outreach programs, as well as contacting and keeping engaged with landowners about land conservation and stewardship programs.

By Jonathan Poll, AIWC Volunteer

References

Patton, J.L. (2005). “Family Heteromyidae”. In Wilson, D.E.; Reeder, D.M. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 847.

http://www.sararegistry.gc.ca/default.asp?lang=En&n=CCF2EBBC-1&offset=11&toc=show

Finnamore, A.F., and D. Buckle. 1999. Arthropod component report: the stinging wasps (Hymenoptera: Chrysidoidea, Vespoidea, Apoidea) and spiders (Araneae), Canadian Forces Base Suffield National Wildlife Area Wildlife Inventory. Report for Canadian Wildlife Service, Prairie and Northern Region, Edmonton, Alberta. 199 pp.

http://naturecanada.ca/what-we-do/naturevoice/endangered-species/know-our-species/kangaroo-rat/

http://aep.alberta.ca/fish-wildlife/species-at-risk/species-at-risk-publications-web-resources/mammals/documents/SAR-AlbertaOrdsKangarooRatRecoveryPlan-2013-2018.pdf

Photo Credit: By NPS (http://www.nps.gov/glca/naturescience/mammals.htm) [Public domain], via Wikimedia Commons