© 2024 KALW 91.7 FM Bay Area
KALW Public Media / 91.7 FM Bay Area
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations

The dung beetle census is a window into their ecosystem

JUANA SUMMERS, HOST:

Now to a search for dung beetles in Massachusetts. Science reporter Ari Daniel brings us this story about the vital role these insects play in nature and what they have to say about the health of the forests they call home.

ARI DANIEL, BYLINE: It's a beautiful late fall morning. Unseasonably warm, but...

ERIN MCCULLOUGH: I was just going to say, I'm going to have to get rid of this sweatshirt.

DANIEL: Erin McCullough and I are walking in Hadwen Arboretum, a small patch of woodland in the heart of Worcester in the central part of the state. Swirls of yellow maple leaves cascade to the ground. It's here on the forest floor, where McCullough goes on safari.

MCCULLOUGH: I have found 12 different dung beetle species.

DANIEL: Twelve?

MCCULLOUGH: Yeah. I think people don't appreciate the biodiversity that's right in their backyard.

DANIEL: McCullough, who's a biologist at Clark University, has been scavenging for dung beetles twice a month since April. She found them starting to emerge in May. Their numbers peaked in July. Then last month, she only found a few.

MCCULLOUGH: I'm interested in figuring out who's here.

DANIEL: By far, the most common species she's turned up is the size of an apple seed.

MCCULLOUGH: It's a really beautiful, green, iridescent beetle. When we're sifting through the poop, it's kind of like finding this jewel (laughter).

DANIEL: And, she says, these jewels are really important.

MCCULLOUGH: Dung beetles are nature's cleanup crew.

DANIEL: They break down waste, improve the soil and aerate the forest floor. And in the U.S., one study showed that dung beetles provide services valued at almost $6 billion annually.

(SOUNDBITE OF FOOTSTEPS)

DANIEL: McCullough crouches down beside a trap she set out the day before.

MCCULLOUGH: I have buried a Nalgene bottle so that it's flush with the ground, and then I bait it with poop.

DANIEL: Either from cows or, in this case, her dog.

MCCULLOUGH: I joke that every time Maggie takes a poop, she's contributing to science.

DANIEL: McCullough says the science - her dung beetle census - matters because these insects are like little windows into the health of their ecosystem, including an urban forest like this one.

MCCULLOUGH: Dung beetles can be used as indicators of habitat quality, so they're very sensitive to climate change or deforestation.

DANIEL: So the greater the dung beetle diversity, the healthier the forest. McCullough is also interested in the flipside, how big a forest has to be to ensure a robust dung beetle community.

(SOUNDBITE OF SCRAPING)

DANIEL: McCullough pulls up the Nalgene and scans the inside quickly.

MCCULLOUGH: I don't really see any dung beetles.

DANIEL: Still, it's possible one's hiding in the dung. So after gathering up the remaining traps, we head to her lab on campus.

MCCULLOUGH: So this is the beetle room. It takes a special kind of person to sign up to work in a dung beetle lab.

(LAUGHTER)

DANIEL: One of those special people is undergrad Beatrice Altopp. She grabs a spatula and dives in.

BEATRICE ALTOPP: It looks like chocolate frosting.

DANIEL: Alas, despite the warm day, the search doesn't yield any beetles. McCullough last found them in her traps in late October, so it really seems that the dung beetles have gone underground for the coming winter. But before I leave...

MCCULLOUGH: Do you want to look at him under the microscope?

DANIEL: Yes, please.

...I gaze into the eyepiece, and a little iridescent alien swims into view.

Oh, my goodness. How gorgeous.

Undergrad Charlie Fox-Whelpton agrees.

CHARLIE FOX-WHELPTON: You think of, like, minotaurs. You think of, like, really epic little creatures, and I think it's really cool that we find these in Massachusetts.

DANIEL: McCullough will resume her hunt in the spring when the latest batch of these epic beetles find their way out onto the forest floor in search of all the fresh new waste to revel in.

For NPR News, I'm Ari Daniel. Transcript provided by NPR, Copyright NPR.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.

Ari Daniel is a reporter for NPR's Science desk where he covers global health and development.