Going Batty with CMNA

On October 16th, 2024, Lydia Moore, Research and Education Manager for the Palmetto Bluff Conservancy, shared with us a fascinating presentation on the beneficial roles bats play both locally and globally for our October Think & Drink Zoom meeting . If you missed it, you can find it on our recorded T&D page.  On the following Friday evening, about 15 CMNA members met at Caw Caw's new, usually closed, Tea Creek property (probably not its official name) to try to see and, more likely, record and identify some bats.  That site is known to have bats roosting in an old dog kennel on the property.

As can happen with any field expedition, the weather was not ideal. It was quite cold out, and the bats were not very active.  One or two folks saw a bat flying, I think, but most of us did not see any.  However, this wasn't quite the issue it would have been with, say, birds, since you  don't usually identify bats visually, at least while they are flying. Instead the main way to ID them on the wing is to record and analyze their calls. We did get recordings of several bats, most of which went unseen, via an Echo Meter Touch 2 microphone from Wildlife Acoustics.  Lydia had a couple of these units, as did several of our members.  This small, high-frequency microphone connects to a cell phone or tablet to pick up the 30,000Hz+ sounds bats produce.  The associated app then tries to automatically identify the calls heard.  It can also frequency shift them down and play them in an audio range that we humans can hear.  Pretty cool stuff!

As I recall, we were able to hear and tentatively identify several species of bats: Seminole bat, Lasiurus seminolus; Eastern red bat, L. borealis; and a Mexican (or Northern or some other subspecies) free-tailed bat, Tadarida brasiliensis.  There might have been others heard, but those are what I recall being discussed when I was near.  More about the app and its use, later.

Lydia was a wealth of information on the sounds the bats made, which ones we might expect in this area, the behavior, and much more.  Of course, when you put a bunch of naturalists into a new bit of nature, there will be a lot of "off topic" investigation and group sharing.  That is frequently my favorite bit of our wanderings.  In this case, since the meeting began just before sunset on October 18th and many of us (at least me) hadn't had a chance to see the "comet of the century", A3, (full  name comet C/2023 A3 (Tsuchinshan-ATLAS)), we decided to walk down an apparently clear mowed path out to the salt marsh and see if we could find the comet.  The timing was right, there were no lights (besides our own) around, the trees currently around us were too tall, and we could still listen for bats.  It seemed a great plan.

The walk was quickly made, with the  most challenging part being not walking into low branches and, at the end, not walking off the bank into Tea Farm Creek.  It was that dark! Unfortunately, despite our best efforts with binoculars and naked eyes, we could not find the comet.  Apparently, it was still too low to be seen since there were still trees on the horizon, just further away.  However, the walk was completely worth it, the night was quiet and peaceful, there was an amazing sunset, and we even saw a rocket as it had been launched from Cape Canaveral. Check out the picture at the top of this article.  The rocket is above and to the left of the setting sun.  The bright light to right is a plane; one can only get so far away from man's traces.

After enjoying the sunset and looking in vain for the comet, we finally decided to head back.  Since most of us had flashlights or headlamps, we began trying to find spiders by their eye-shine.  It turns out there were a lot of them, many more in the surrounding woods and leaf litter than on the mowed path.  I think we mostly found Carolina wolf spiders,  Hogna carolinensis, probably because it was big and easier to find by flashlight than all the little spiders. Here is an shot of the action:

Remember when I mentioned that the comet must have been behind the trees?  Well, I tried taking several pictures of where I thought it would be in hopes it would be more visible in a photo (like the aurora was for many folks).  Unfortunately, I couldn't see anything different on my phone at the time.  However, a couple of weeks later (literally), I got around to looking at the photos again.  One of them was where I had used a time-lapse mode designed for low light conditions. Holy cow!  There was the comet!

Check it out, it is in the above the trees about one third the way in from the left side.  If you took any pictures, and didn't initially see anything while we were out there, I encourage you to take another look.  It was easy to overlook in the dark when my screen seemed way to bright.

One final note about the bats.  I often see bats around my house, so after this event, I decided to get a microphone and try to ID them.  A few weeks later, I was ready to go. The "Echo Meter Touch Bat Detector" app that is used with the microphone is interesting and shows both a visual representation of the calls and plays them at a lower frequency so we can hear them.  I thought I'd share what the app looks like in action. Here are four  screenshots of the app showing, from left to right, first: a call from a Seminole bat (from a recording I made in November); second: the associated bat ID screen one gets when the yellow bat icon is selected, showing the Seminole bat as the most likely ID, but an Evening bat as another possible match; third: another call from a Tricolor bat, notice the differfent shapes and pattern in the sonogram (lower portion); and forth: the linked ID screen showing only one possible match.  If you want to hear what the Seminole bat call sounds like through the app, you can hear it in this video (the easiest way for me to link a sound file for you): https://youtu.be/ryqSAI1sw2A.

All in all, I found this Think & Drink and the Walk  & Talk to be fantastic learning experiences.  I encourage all of you to learn more about the bats in your neighborhood.  Also, if you think of more night walk adventures, be sure to let your CMNA leadership team hear your suggestions!