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In this Episode meet

  • Mac Callaham, Project Leader/Research Ecologist, Athens, GA

Searching for Cicadas in the Chattahoochee National Forest

Produced and hosted by Jonathan Yales - 7 min.

Mac Callaham, a research ecologist, goes searching in Georgia’s Chattahoochee National Forest for one of Brood X’s most-southern cicada emergences.

Mac Callaham
Today is Sunday, June 6th, and I am headed to north Georgia to see if I can locate, and/or record, some cicadas singing. So, here we go. We're off for about the next hour and 15 minutes of driving, and then, I'll check back in.
Mac Callaham
Okay, here I am. I'm in the Chattahoochee National Forest in Lumpkin county, in northern Georgia. I'm in the Bull Mountain area, and I have just gotten out of the truck and walking through this little parking lot area here, and I can hear cicadas already. Maybe you can hear them in the background? Now, I'm going to see if I can get a little bit closer and find out where they're emerging from, where the chorusing center is.
Mac Callaham
All right, well, I've just gotten into the woods proper here, and already seeing signs of the emergence. I've found a few dead cicadas, so that's a sign that we're kind of getting towards the end of this emergence’s cycle, but there are still some chorusing individuals in the area, so I'm going to see if I can get a little closer.
Mac Callaham
Been walking for a few minutes now. I feel like I'm definitely getting closer. Seems like the calling is getting a little bit louder. Can hear it in the distance. Still not quite there yet, but getting closer.
Mac Callaham
Okay, I've now hit a spot where the Forest Service has done a prescribed fire, which makes it a little bit easier to walk through the woods, and it also makes it much easier to see the emergence holes. Still haven't gotten under a really good, loud chorusing center, but I'm going to keep looking and hopefully I'll be able to turn something up before too long.
Mac Callaham
Hi, I've just come to a spot where the noise is getting a little bit louder. I'm standing here in an area that's, maybe, one square foot. I'm counting one, two, three, four, five, six, seven, eight, nine, emergence holes. And, very interestingly, you can see where they pushed up some soil when they emerged, but this is really good evidence of the kind of bioturbation that I was talking about before—very cool. I'm kind of having a little bit of a nerd moment here in the woods. Also, of note, is the fact that just right here in view I can see the bodies of one, two, three, four—just right here in this little area that's maybe, a square yard—four dead cicadas. So again, the cycle for this 17 years is about to come to a close, at least the above ground part of it, and again, the question occurs to me: what is happening with all of this biomass? As I look at them, I can see that they're mostly hollowed out, which suggests that maybe some ants, or something like that, has already gone inside and gotten the juicy bits.
Mac Callaham
I guess, I'm slowly coming to realize that I've been walking under a chorusing center this whole time. They’re just way up high in the canopy. I sound like I'm completely surrounded, but it's not as loud as I expected it to be. I think that's probably because I got here too late in the game for it to be as spectacular as it can be. Anyway, I hope you can hear that low buzz that is completely surrounding me right now. I haven't completely given up hope, but I'm starting to wonder if I'm ever going to get any truly spectacularly loud stuff.
Mac Callaham
Well, two things I'm learning about Brood X: they're a lot more spread out then they are in Kansas, which I guess I could have expected considering how many more trees there are—if you've got trees going for miles in any direction, it's hard to pinpoint where they're going to be. So, that is in sharp contrast to Kansas, where the trees are very restricted and we know where the bugs are going to be. Another thing, another really cool thing, that I saw today was a predatory beetle—like a carabid beetle—with its head stuffed up into the abdomen of a cicada that had recently died. So, there’s an answer to at least one piece of the puzzle of where the nitrogen and carbon goes from cicada biomass. It's obviously a food source for other critters on the soil surface. Anyway, I'm sitting here in the parking lot, I'm noticing cicadas flying all around, so, I'm here, and they're calling, I can hear them, I just can't get under a really loud chorusing area. So, again, I say that's probably due to my late arrival. And, yeah, that's what I got for Brood X so far. That counts as a good day for me. Alright, talk to you later, Jon.
Jonathan Yales
This podcast is produced by the Forest Service, an agency of the U.S. Department of Agriculture. The USDA is an equal opportunity provider, employer, and lender.
And, this episode's music was by Blue Dot Sessions.
Thanks for listening.

Meet the Scientist

Research Ecologist Mac CallahamA Project Leader/Research Ecologist for the Forest Service's Southern Research Station, Mac Callaham is interested in soil. His work focuses on how forest management activities such as tree harvest, thinning, and prescribed burning affect soil and the endlessly fascinating organisms that are at home in soil, such as insects, earthworms, and a whole host of microbes.


Images

Cicada emergance hole in soil.
Brood X Cicada emergence hole in soil. USDA Forest Service photo by Mac Callaham.

Cicada shell hollowed out.
Hollow shell of a brood X cicada. USDA Forest Service photo by Mac Callaham.

Carabid beetle eating the inside of a dead cicada.
Carabid beetle eating the inside of a dead cicada. USDA Forest Service photo by Mac Callaham.