Bats have been around more than 50 million years and there are more than 1400 species.  Yet most of us know little about them.  We may know about their scary appearances alongside witches and vampires in the dark of night in ghost stories and fairy tales.  But we may not know about the actual superhero work they do in pest control, plant pollination and seed dispersal.

In the current era of climate change, environmental destruction and the global pandemic, bats increasingly are also being recognized as an important “indicator species” (https://www.bats.org.uk):  they give us signals of loss of biodiversity and they remind us of the risks and damages created by human encroachment on animal habitats.  In the era of Coronavirus 19 we are seeing how human interference and environmental destruction have created new pathways for viruses to jump ship and move over from the host animals with whom they have long peacefully cohabited to human populations where the same virus may wreak pandemic havoc.  Reclaiming and creating habitats for bats not only enables bats to continue to do essential work for the planet but will also help keep intact habitats for the viruses that live with them.

Since 2006, millions of bats including the Quebec Northern long-eared bat have died from White Nose Syndrome WNS ( https://www.whitenosesyndrome.org/static-page/what-is-white-nose-syndrome ).  WNS is caused by the Pd fungus (Pseudogymnoascus destructans).  The fungus wakes up hibernating bats causing them to deplete their winter fat stores too early and to die of starvation.  Bats with WNS may also leave their winter roosts too early flying out into freezing temperatures and dying of hypothermia.  Although humans are not affected by WNS, they are thought to be responsible for importing the Pd fungus spores to North America on shoes and clothing.  This is further evidence of the web that binds animal welfare to human activity and reason for humans to work to create and rehabilitate habitats for bats including building bat boxes, renaturalizing urban green spaces and yards and practising pesticide–free farming.

Where Do Bats Live in Quebec?

Bats live in roosts.  Two species — Little Brown Bat (Myotis lucifugus) and Northern Long-eared Bat (Myotis septentrionalis) — are common to Quebec.  Both are non-migratory and hibernate in Quebec.

Bats move around to different roosts at different times of year.  In summer, females gather in colonies in tight crevices to form a warm, safe maternity roost to have and nurse their young.  They may roost in tree hollows or under bark.  Or they may use the built environment and roost in barns or churches, under shingles or behind shutters, or in attics and roof spaces.  In winter, Quebec bats hibernate for 8-9 months in colonies in roosts that keep a stable, low temperature often underground in caves, mines, cellars and service tunnels where they will not be disturbed by light, noise or predators.

The Work Bats Do

Bats are mammals.  Like humans, they carry and nurse their young with milk.  But bats are also the only mammals that can fly and they like to hang upside down.   Unlike other mammals, bats are nocturnal:  they work and feed at night.

Night is when bats do their important work: pest control.  Bats eat beetles, moths, mosquitoes, crickets and other insects.  The nocturnal work bats do eating insects saves North American farmers billions of dollars in crop damage by insects.  A healthy bat populations reduces the need for pesticide sprays.  Yet industrial agriculture relies on pesticides that destroy habitats for bats.  Large-scale commercial agriculture has also eliminated hedgerows and woods between fields that offered roosting sites for bats.

Bats are also essential workers as pollinators.  Over 500 plant species rely on bats for pollination (https://www.batcon.org).  And some bats play a critical role in spreading the seeds of trees and other plants and can play an important role in reforestation after logging, fire and urban development projects.

Loss of Bat Habitats

Despite the essential work bats do for humans as pest exterminators, plant pollinators and seed spreaders, humans are the main cause of the startlingly rapid decline in bat populations worldwide.  Urban expansion destroys natural woodland habitats.  Bats have adapted by making roosts in buildings but chemicals and plastics now used in construction make new buildings uninhabitable for bats. Human use of pesticides and intensive farming practices kill insect populations that are bats’ only source of food.  Highways create open spaces that bats have difficulty crossing: bats like to fly close to trees for protection from weather and predators or they fly close to the ground which puts them in the path of traffic.  As nocturnal animals, bats are disturbed by night pollution — excess lighting from streetlights, for example.  So bats delay leaving their roosts after dusk reducing the time they can forage for insects.  This puts the survival and growth of their young at risk.

For bat populations to recover and survive, we need to create new habitats and enhance the habitats that remain.  More people are starting to protect bats by building bat houses and by keeping their gardens chemical-free.  Their rewards are:  natural insect control, no bats in their cellars or attics and lots of fun bat-watching.

Building a Bat Box

Bat houses should be made of exterior plywood or rough cedar and be at least 24” tall and 14” wide and 2”-3” deep so bats can move around.

For bats to hang easily, the inside should have grooves every ¼” or be lined with 1/8” plastic mesh stapled to lie flat.

To protect the bats from blue jays, racoons, snakes or other predators, entrance slots should be no deeper than ¾” – 1”.

The house should have a landing that extends 4”-6” below the entrance to allow bats easy access in and out.

An angled roof will allow rain to run off.

A ventilation slot about one-third of the way from the bottom will give the bats warmer and cooler areas to move between.

Caulked joints will help bats keep warm and dry.

Galvanized screws will prolong the life of the house.

Choosing a site for your bat house:

To take flight, bats usually need to free-fall several feet when leaving the house to feed at night.  Mount bat house at least 12 feet off the ground, the higher the better to be safe from predators.

Bats need an open area around the entrance to give them room to swoop in and out of the house.  Make sure there is at least 15-20 feet clearance in front of the house.

Bats like a warm place to raise their young.  Face your bat house south or southeast to take advantage of direct sunlight.  Paint the exterior of the house with a non-toxic black paint to absorb the sun’s heat.

For bat house designs, check out:  www.batconservation.org.  See also “Putting up a Bat House” at: https://cwf-fcf.org/en/explore/bats/bat-house.html