After our celebration of “Bat Week” in late May, quite a few questions about bats were sent in to Maine Audubon. Fortunately, many people are aware of the disastrous declines in many of our bat populations. But from the questions I’ve received there seems to be a bit of misunderstanding about what we can do to help bats, so I thought I would try to clear up some confusion and provide some tips and resources for you to use in helping our bats recover.
An important thing for people to know is that Maine’s bats can be separated into two groups: the non-migratory “cave bats” that overwinter here, and the migratory “tree bats” that leave Maine in fall and return in the spring. We have a total of eight species of bats that occur in Maine. Five of them are resident cave bats, while the other three are migratory. White-nose syndrome (WNS), the fungal disease that is causing the dramatic declines in bats, is transmitted in caves, so it is only the bats that hibernate in Maine that are seeing the 90 percent or more decline since WNS was first detected in Maine in 2011. The other tree bats may be faring better, but knowing the declines in insect populations that are occurring, those must be struggling as well.
We get many questions about bat houses. What kind should be used? Where should they be hung? Why aren’t there any bats using it? Quick answers would be: The bigger the better; at least 10 feet, but ideally 20 feet, off the ground; and sometimes it takes bats a few years to start using a box – they’re not like birds that can move in within days. Many situations will need more specific answers, almost all of which can be found from a wonderful group called Bat Conservation International. Check out the website, batcon.org, for helpful information, especially on the “About Bats” tab.
Another question is, how can I identify the bat silhouettes flying around? One cool tool you can use for monitoring bats is an acoustic bat detector. There are a range of detectors out there, but I recommend the user-friendly Echo Meter Touch 2 Pro, a device from Wildlife Acoustics that you can attach to your phone to detect and identify bats’ echolocations. Bat detectors can range from a few hundred dollars to a few thousand for professional applications, but the $350 Echo Meter is pretty impressive and very easy to use (though, same as with the Merlin bird app, be aware of imperfections with these devices). Watching how different species have varying foraging behaviors has been especially interesting for me the last few years. Knowing which species you are detecting often helps make a connection to the need to help. For example, if you identify a northern long-eared bat flying around your yard, then you’ll know that more than 97% of its population has been lost.
Lastly, if the fact that over two billion birds per year are killed in the United States by outdoor cats isn’t enough of a reason to keep your cats indoors, the need to help bats should be. Cats, which are non-native surplus hunters (they kill even when they’re well fed), are only here because we humans introduced them. They are one of the most common causes of mortality in bats. Please keep your cats indoors, especially during the summer months when bats are feeding their babies.
LEAVE THOSE BABY BIRDS ALONE
I hate repeating topics, but as we head into June the nesting season is in full swing and we receive many calls from people who find baby birds. I’ve shared many of these tips before, but it is worth repeating again, and please share this around. First and foremost, remember that in most cases, baby birds don’t need your help.
Encountering baby birds, or other wildlife, usually triggers an instinct: We need to do something to help! Unfortunately, most of the things that we would do to help an ailing human can actually be detrimental to wildlife. In most cases, you should leave any baby animals alone. The adults are often nearby and won’t return because you are too close. Keep in mind the often-shared motto: “If you care, leave them there.”
Though there are always exceptions, I believe that well over 90% of the cases we hear about each year involving baby birds would have the best outcomes with no human intervention. Young and undeveloped birds may look sickly but that’s because they’re just still growing in all their feathers. Always remember that birds have a couple of days after they leave their nest (a dangerous place to stay too long because of predators) when they will be very awkward and often not yet capable of sustained flight. And again, they’re not abandoned; the adults may be in hiding, waiting for you to leave.
If you do find a bird that is sick or injured, you should contact a licensed wildlife rehabilitator to see if intervention is necessary. Avian Haven and The Center for Wildlife are good places to start; and the Maine Department of Inland Fisheries and Wildlife (mefishwildlife.com) also keeps a list of licensed rehabilitators.
Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about backyard birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug leads free bird walks on Thursday mornings, 7 to 9 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.
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