How strobe ants do the strobe run

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It’s been a while since I posted about some of the science I’ve been doing, so here’s a fun natural history story for a change.

If you have the fortune of being in the northern end of Australia, your eye might be caught by ants running at your feet, appearing to be under a strobe light, paradoxically in the light of day. These gorgeous ants (see above) are colloquially known as strobe ants (genus Opisthopsis). They’re remarkably common, and definitely catch your eye.

I dug into the literature to learn what we know about Opisthopsis. The answer is shockingly little. For such an obvious and cool ant, there’s been essentially no work on its biology that we could find in the literature. They’re a blank slate, at least since William Morton Wheeler wrote about them one century ago.

I was going to spend some days in Darwin (orienting students for a half-year research experience, thanks to the generous support of the National Science Foundation) and I had a few days to knock out a quick project. I thought it would be fun to ask: How do strobe ants strobe? It really looks like they’re jumping as much as running, like a jumping spider. I knew when collected in ethanol, their legs broke off very easily, far more than other ants. What’s going with their leg musculature?

I was going to take a bit of time to film some strobe ants. The problem is, they’re so fast, if you just watch them or use regular video, it’s just a blur, because they’re so darn fast. I did some homework into borrowing or renting a high speed camera while I was up in Darwin. It turns out this would have been absurdly inconvenient and very expensive. While asking folks about high speed videography on twitter, it was pointed out that the slo-mo function on recent iPhones would record 240 frames per second. Some back-of-the-envelope math with my colleague James Waters suggested that would be just enough to catch how Opisthopsis strobe.

So I prematurely upgraded my phone to get a high tech videography tool before I headed to Australia, where I was hosted generously by the Tropical Ecosystems Research Centre of the CSIRO. I also packed a bunch of microscope slides, because I got a great tip from James to use an old-school method to record ant gaits that he picked up from decades-old physiology papers – if you smoke glass with a match, and let insects walk across it, you can record their footsteps. It worked better than I had imagined it would! This project organically evolved into a collaboration where I’d get to play with the ants and record the video, and Professor Waters would do the gait analysis, using tools and code that he’d already used for a previous project. (Yet another collaboration that started on twitter!)

Once I got my lab rig set up, I snatched up some ants (which is harder to do than you might think, because strobing) and brought them into the lab, and voila:

How weird! they’re doing a RUN – STOP – RUN – STOP – RUN – STOP and so on, whenever they’re just moving from point A to point B. That’s what strobing is. Each and every stop, they discretely and firmly tap the ground with the tips of their antennae, then they start their next strobing step once their antennae get lifted to the full and upright position. They’re not jumping — they use what looks like the standard insect tripod gait, but they’re doing it so fast, that at a brief moment, all six legs might be lifted off the surface and moving.

In the video below, you can see their rapid acceleration and deceleration. They’re at rest for double the time that they’re actually moving! Watching the strobe at regular speed, I wouldn’t have guessed this at all. They’re spending more time checking the ground with their antennae than they are moving. And, they clearly are making a solid tap on the surface because their antennae mark the smoked glass as much as their feet do.

I didn’t walk into this work with any particular hypothesis. I first wanted to actually see what strobing was before I tried to develop a clear idea about why they’re doing it! And now that I see what strobing is, well, I’m more boggled. Which is so cool, don’t you love a good mystery? We’ve got a few wacky ideas. The most sensible one is that the ants are running so fast, that their brains can’t keep up with the visual input, so they need to stop so that their brain’s can make sense of the input. This might sound far-fetched, but this is apparently what some extremely fast-running beetles do.

There are some other insects that do the strobe-walk, and one thing they have in common is mighty big eyes. We don’t have a Unified Theory of Strobe Gait, but maybe we’ve done a bit more to inspire folks to work on this. If you’ve got an iPhone, this is something that you can do on your own, too!

Our paper with these results, and more, has just come to press:

Waters, J.S., and T.P. McGlynn 2018. Natural history observations and kinematics of strobing in Australian strobe ants, Opisthopsis haddoni (Hymenoptera: Formicidae). Myrmecological News 27: 7-11.

I don’t have any immediate plans to go back to work with strobe ants, though it would be fun.

How do I manage to do all the things?

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Women so often are asked: “How do you juggle family, career, and everything else?” But men are rarely asked about balancing family and career, with the implicit assumption that they aren’t spending substantial time or effort on family affairs. I think this doesn’t represent the actual state of affairs in many households, though it is still true that the average guy doesn’t do his fair share of parenting and household work.

Women-in-science who are parents are typically cast as moms by public and professional eyes, while men-in-science who are parents are not cast as dads. This sets up unrealistic and unfair expectations. Continue reading

“What are you doing on campus in the summer?”

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I’m back from vacation! Anyhoo, a funny thing happens to me every summer.

Campus has an eerie quiet. There are plenty of people around, but compared to the academic year, there are relatively few students. So if I’m walking from the parking lot, or buying lunch in the union because I was lazy, I might bump into someone. Because I serve on a semiplethora of committees, I know folks in lots of roles on campus.

There’s a pretty good chance they’ll ask me: “What are you doing here? Are you teaching a summer course?” Continue reading

An education in academia

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I’m in the field right now. Which means that I’m among many fellow academics, from a wide range of institutions, because we’re working out of La Selva Biological Station to do a short project. At the moment are faculty and grad students from a range of Latin American universities, and USian institutions including a regional state university, small liberal arts college, tribal college, HBCU, military academy, state research university, and some researchers from other kinds of organizations. Many of these folks are old friends, so being here is a great pleasure.

We’re here to run experiments to answer some specific research questions, but just as important, we’re here for the academic training of undergraduates. The two goals are quite complementary. You would think that what the students are getting is research training. They are getting that, but they’re also getting another kind of training: an introduction to the culture, conventions, and social mores of becoming an academic scientist. Continue reading

The mentorship problem in primarily undergraduate institutions

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I’m back down at the field station in Costa Rica (missing my family quite a bit) and I had a very minor realization while having dinner among my students. It’s definitely a cliché of sorts, but I realized that the t-shirt I was wearing was older than some of my students.

I know this because the t-shirt had a specific date on it Continue reading

And even more sincere answers to stupid questions

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Once in a while, I look at the statistics for this site and I get to see some of the search terms that folks use to arrive here. Sometimes these are questions that may have gone unanswered. So, here are some of these queries, and my replies. (I’ve done this plenty before by the way, though it’s been a while.) For each search term, I provide a response. (The title, by the way, is an homage to MAD’s “snappy answers to stupid questions.”

 

how to destroy a bad graduate advisor

Tell them you’re planning to become a sales rep after you finish your dissertation.

 

how to get out of academic dishonesty

I guess you should lie? Continue reading

Efficient teaching: frequent assessments

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If your teaching is at least modestly informed by the scholarship of teaching and learning (and, I dare suggest, it should be), then you are probably aware that frequent assessments are a good thing. Students learn better when they have more opportunities to find out if they’re learning what is being taught.

But — as Meg Duffy pointed out last week — some teaching practices are effective but may not be sustainable because they might just require so much work from professors. This resonated with a lot of people. A lot of us apparently feel a genuine tradeoff between our capacity to teach effectively and the amount of time that we are expected to invest into teaching each of our courses. Continue reading

Please focus more on inclusion so that diversity recruitment efforts can work

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I realize that recruiting students from underrepresented groups in STEM is not the most popular broader impact when scientists are actually implementing federally funded research projects. That said, I see a lot of folks putting so much time and effort to recruit minority students. And folks working to provide opportunities to minority students. Continue reading