Step #1 | This is When We Realize How Little We Really Know About Bats
Step #2 | Find Out About Our Local Bats
Out of the 1300 species of bats worldwide, Maryland is home to 10.
Ten Species of Native Maryland Bats
The order of Bats species, Chiroptera, is split into two groups. Maryland’s bats all belong to the same group (Microchiroptera): bat species found in almost every habitat type on Earth, that eat mainly insects and echolocate to find their food. The other group (Megachiroptera) contains mostly tropical bats– fruit or nectar eaters that use their large eyes and noses to find food. Both play critical roles in balancing ecosystems and provide inestimable benefits to human health, agriculture and economy.
Two Types of Maryland Native Bats
In Maryland, our bats can be subdivided into two different types, Tree Bats or Cave Bats. This differentiation is based on their hibernation & roosting preferences. Tree Bats generally migrate or spend the winter in tree cavities, under loose tree bark, or tucked in under trees beneath leaf litter. Cave Bats tend to hibernate in caves, tunnels or mines.
One Serious Situation
We are disturbed to find out that all ten species of Maryland bats are designated Species of Greatest Conservation Need. Even worse, several species are also designated as ‘rare in state’ currently.
Because human disruption of bats natural habitats is largely to blame, trying our best to restore or recreate just a small patch of it seemed like the right place to start. And also something that we’d enjoy doing together, as a family. We already support wild birds, native bees and butterflies in our backyard. How could we include bats?
We started by learning about our local bats.
Step #3 | Planning a Bat-Friendly Backyard
After doing a survey about all our local bats, the strategy is to approach planning a bat-friendly habitat the same way we started our micro-habitat for birds. Keep it simple. Begin with the three simple elements that make up a habitat: food, water and shelter.
FOOD + WATER + SHELTER = HABITAT
Bats and Food
This one is easy! Our native local bats are insectivores. The best thing we can do is “nothing”. Stop using pesticides , stop mowing lawns and stop raking leaves! A habitat with native plants left alone to do their thing… the insects will come.
If you’re wondering which native plants could be most helpful to bats, think about what happens in the garden after dark. Bats are nocturnal and they come out looking for insects that are also active at night. Plant night-blooming natives that attract tasty insects.
First of all, no more pesticides, EVER!
Got Insects? For sure, there are a gazillion mosquitoes after all this rain. How to make sure it’s a variety of insects that will attract bats? Garden for wildlife. (Read Douglas Tallamy ‘Bringing Nature Home’, see resource links below.)
Get a pollinator garden for songbirds, bees and butterflies underway.
Add plants that also make it a ‘Moonlight Garden’ with night-blooming native plants . Here are a few recommended native plants that will work the night shift in a bat-friendly habitat:
- Evening primrose
- Night flowering/Silene catchfly
And finally, again, stop doing so much yard work. (Yay!!! No raking leaves this year!) This year, let an area in the backyard “go wild” and see how it goes.
FOOD + WATER + SHELTER = HABITAT
Bats and Water
Bats need fresh, accessible water to drink. Many drink daily. And again, just like night-blooming plants, water will attract the insects that attract hungry bats.
What are bats looking for as water source? Room to swoop across it, scoop up a sip and keep flying. That means a water source with a larger surface area that is unobstructed by trees and vegetation. In the wild, bats would be choosing to roost in proximity of lakes, ponds, or slow-moving streams. They may also use raised birdbaths that are located in an open space. And we found anecdotes of bats using mud puddles on country roads and skimming across urban swimming pools (chlorine can’t be good for them?).
For the most part, bats require a larger surface area for a water source and the amount varies with the species. That makes sense, since we’re finding out how much bat wing sizes differ between species. Just like airplanes need different length runways. Bat Conservation International estimates most bats need a water surface area at least 10 feet by 2.5 feet.
Note: Bats are very susceptible to drowning if they are trapped in a water source without an escape route.
Is there a natural water source within a quarter of a mile?
Is it possible to “re-dedicate” a larger raised bird bath and place it for bats? What if it’s placed allowing more “runway” without any obstructions?
Might need to think outside the standard bird bath approach. We still have questions and need to research this further.
FOOD + WATER + SHELTER = HABITAT
Bats and Shelter
First, we need to learn the lingo! Bats roost.Second, we’ve learned they have more complex shelter requirements than birds. In order to survive, they need places to sleep and raise their young in the summer, and for those who do not migrate, places to hibernate or roost in the winter. Some bats even switch roosts for day and night during the heat of summer!
Bat societies are also complicated. Some bats are solitary all the time, some are solitary when they’re not reproducing, but join colonies to birth and nurse their young. Other bat species crowd together in small spaces for the duration. There is a lot going on with bats!
Caves, old stand forests with deciduous trees and conifers, wedged between loose bark and tree… nature has all kinds of places for bats and they’ve evolved to make the best of them. You’ll find them all over the world, in every kind of climate. Bats have also adapted to take residence on buildings, in tunnels, under bridges and probably some places we’d rather they’d not. As long as we continue to ruthlessly disrupt, build over—or mine the heck out of—their original habitats, this is the new normal.
The compromise for all of us, but doesn’t seem like nearly enough, considering, are well-designed and constructed bat houses.
Buy a bat house to get started. There are options and good advice out there.
There are plans and guidance available for building a bat house.
How to choose a good bat house: Look closely and see if it’s designed and constructed within the certification guidelines from Bat Conservation International (BCI). Ditto for choosing bat house plans if you want to build one yourself.
See links in Resources below. If you’re confused about which to buy, you can’t go wrong by buying one that’s officially BCI approved. A badly-designed or poorly-constructed bird house can cause harm.
Watch BCI videos about bat houses: where to put a bat house, how to install it.
Research additional protective shelter we could provide for bats in our suburban back yards, with creative landscaping or by just letting nature take over an area.
Leave a snag! (A dead tree is called a ‘snag’.) Bat experts say to leave it alone, if it’s not dangerous, and let wildlife adopt it. It will be a work in progress, but there’s nothing to do except monitor the safety aspect.
Be patient! Everything we’re read about attracting bats to a bat house includes “Be patient!”. The reality is that it takes time for bats to adopt a new bat house. Sometimes a couple of years.
The bottom line is that not all Maryland bats will roost in a bat house, no matter what we do. Maryland Department of Natural Resources website says MD native bats most likely to adopt bat houses are: Little Brown Bats, Big Brown Bats, Northern Long-eared Bats, and Evening Bats. We will need to research ways to help the other six species of local bats: Eastern Red Bat, Hoary Bat, Silver-haired Bat, Eastern Small-footed Bat, Indiana Bat and Tri-colored Bat.
Step #4 | There is No Downside to Trying!
Once we have the bat house up, we’ll watch and wait. We’ll keep trying to figure out how to provide a water source that’s accessible for bats. And, we’ll keep working on our garden and supporting other native pollinators in the meantime. Every little bit we do to improve the habitat will benefit everyone. There is no downside to any of this effort! No matter the size, all of our backyard habitats contribute. Backyard by backyard, across Maryland and the entire country, together micro-habitats are making a difference.