[Indistinct chatter] Ummat: There's a guy named Nui here who hosts beetle fights at his house.

And he gets a lot of different people who are really excited, enthusiastic about beetle fights in his backyard.

And I've been invited to his house.

So I'm really excited to see how this works [Indistinct chatter] [Speaking local language] [Cheering] Narrator: Like the New Zealand giraffe weevil, rhinoceros beetles in the wild size up their opponents before fighting.

Here, they're divided into strict weight classes.

Locals size them up by eye, but for Ummat, it takes a bit more precision.

Ummat: I'm measuring the size of the beetle.

We're taking the whole beetle length, including the horn, the head horn, and then we're also taking the width of the beetle, which might give us an indication of the body size itself.

[Indistinct chatter] In boxing matches, we often see strict size classes where individuals fight based on their size class, and we see a really similar pattern happening in nature.

Beetles that are more evenly matched in size are more likely to escalate the competition.

And so they're kind of re-creating what actually happens in nature about this equality in opponent size.

[Indistinct chatter] Narrator: The fight brings enthusiasts from throughout the neighborhood, but is what's good for the culture also good for the beetles?

[Cheering] Ummat: It's important to consider a cruelty element to this beetle fighting.

One of the things that I know as a biologist studying beetles is that these beetles have these horns to fight.

That's what they do in nature.

These beetles have this hard exoskeleton, and much of these fights are a form of signaling.

There very rarely is an injury during a fight and at the of a wrestling competition, the one that retreats, the one that taps out is the loser in that situation.

[Cheering] They're kept very well because they want their beetles to be champion beetles.

So it's really motivating to see all the care and enthusiasm people take and pride they take into how well they take care of their beetles.

♪ [Shouting] Narrator: The fighting arena is a hollow rotating log with a female beetle hidden inside.

The scent of her pheromones triggers the males' competitive warrior instinct.

Ummat: I've been studying insects for a long time, and it's actually very challenging to get insects to compete or to watch them compete.

[Shouting] I've often put two beetles on a log, and they've done nothing for hours [Shouting] And they're able to entice the beetles to fight in these artificial environments, which I was surprised by.

They were able to get beetles to fight almost every time.

[Shouting] Narrator: Ornate sticks help direct the competitors' movements during a match.

In the wild, beetles use vibration to signal to one another.

[Shouting] The wooden stylus may be literally tapping into a form of beetle communication.

Ummat: When people are tapping on the log, beetles are probably using these vibrational cues in nature to tell if there are other beetles around, or perhaps they're telling if there are females that are feeding on the log and creating vibrations.

So we're not quite sure how it works, but it certainly works, and the people here have figured that out.

[Cheering] When the beetles approach each other, they start by smaller pushes and shoves.

[Shouting] You can see their tarsal claws really gripping the edges of the log.

It was really interesting to watch this grappling behavior, just like two wrestlers trying to get the other one into a vulnerable position.

[Cheering] And when one beetle was able to lock onto the opponent in the correct way and lift it up off of the log... [Shouting] It was so clear how that weapon was really well designed for that explicit purpose.

[Shouting] They fight in different ways.

These very big beetles weren't moving as fast as the smaller ones that were more nimble, turning faster, dodging more, were able to do more of this dramatic behavior.

[Shouting] These big ones did these much slower movements, they would grapple for a longer time.

[Cheering] [Shouting] Narrator: The beetle that gets the most lifts or dislodges their opponent is declared the winner.

And the loser is released to the wild.

[Cheering] Finally, the crowd urges Ummat to step into the ring and put what he's learned to the test.

OK, go.

[Shouting] Ummat: I felt so nervous when I had to try to get a beetle to fight and participate in this.

[Shouting] And my stick rubbing skills weren't very good.

I was doing it for the first time, and I really didn't recognize how difficult it was.

[Cheering] Thank you.

I lost, I lost.

I lost very badly, I lost.

But I thought I was winning at first.

[Shouting] Oh, you put a bet on it.

[Laughter] [Speaking local language] ♪ Ummat: This has been an incredible opportunity for me to compare fighting behavior in so many beetles in one place.

If I was coming here as a naturalist, going into the forest and trying to observe this behavior, I doubt I would have been able to see it.

[Shouting] In this culture, an insect that is sometimes seen as a pest is actually prized.

People look at it and engage with it and pay attention to it.

The fact that a community of people in this remote region are paying attention to these insects is extremely valuable.

It creates enrichment in the environment, and it draws people in to paying more attention to insects.

[Shouting]