Thy Butt Gloweth Orange?

Behold! Another story of wildlife just beyond my doorstep! It’s not my fault. I can’t avoid the creatures. They’re everywhere, from the tiny red mites on the railings at school, to the slugs that migrate across my apartment sidewalk at the same location every night. I even have wildlife in my apartment. I know this because every time I eat popcorn at the desk in my home-office, some evil creature steals a couple kernels when I’m not looking and then places them under my desk so I’ll roll over them with my chair. Goodness knows I couldn’t be spilling popcorn myself.

But back to the wildlife outside my Baltimore apartment. A little after sundown a few days ago I was walking in the grass along the edge of the park across the street. As is common this time of year, the fireflies were out doing their thing.

Fireflies remind me of my years in Indiana. I must have been 12 or 13 years old when my family moved from steamy and sunny Florida to the Midwest and its long, chilling winters. One day during my first winter in Northern Indiana the temperature hovered around -14 degrees Fahrenheit. Still, my family’s house in Indiana had a huge perk. Beyond our backyard lawn was about an acre of woods, and down a small hill was a pond, about a quarter-mile long. Other homes were right on the pond, but they were all on the north end whereas we lived on the south end. We couldn’t see the other homes from the pond unless we walked around the point. On our end, we had the waterfront all to ourselves, and the whole thing was surrounded by tall trees. My memories from the pond are so fond that, when I’m in my final days of life, thoughts of my time there will be among those I ponder with the simplest but greatest satisfaction.

My older brother and I helped our dad build a sturdy set of wood stairs straight down the hill through the woods. From there, my dad cleared out a path to the pond and covered the path in wood chips. At the edge of the pond, he then mowed down an area big enough for a fire-pit and a dozen people to sit around it. He also built a short wooden dock and installed two floodlights on 20- or 30-foot studs at the end of the dock so that we could ice-skate after sundown (days are short in the Midwestern winter). We’d sit on the dock to put on our ice-skates, then we’d shovel the snow into a rectangle with rounded edges and play hockey with our school friends for hours on end.

Aside from the mosquitos, summers down on the pond were just as good if not better than winters. My dad had an old slightly waterlogged sailboat. We didn’t bother putting the mast and sail on — there wasn’t usually much wind down on the pond — but the boat had two oar-locks. So whenever I brought a girl over, even just a friend, my dad would suggest I take her out in the rowboat. I’d row and we’d chat while admiring the houses on the north end, and the fish, lily pads, turtles and tadpoles. Some evenings, my marching band pals and I would sit around the fire well into the night and talk about whatever. At other times, my dad and I would stroll around down by pond, talking about girls, my future, my brothers, or my awful grades.

But the end of the dock was where the real magic happened. If the water was low enough, you could sit on the dock without your shoes getting soaked and stare across the pond. On certain nights in the summer, the wall of trees across the pond would erupt into a silent light show. From high in the trees right down to the pond, the fireflies were everywhere shopping for mates.

But here’s the thing, I spent a lot of summer nights down by the pond, and I only ever noticed one color of firefly. In fact, it never crossed my mind that there were more than one species, let alone any firefly whose butt didn’t glow in a yellow-green color. I’ve enjoyed fireflies before and since, but only ever the one color. But on this recent night in Baltimore, walking along the trees near my apartment, I thought my eyes were playing tricks on me.

First, I started paying attention to the fireflies because of how they were lighting up. Several of the insects weren’t doing the familiar slow fadeaway after they glowed. They were flashing on, off, on, off with no fade. This caused me to do a double-take. I couldn’t remember fireflies flashing so quickly on and off. A moment later I forgot about that surprise because I thought I saw an orange firefly. I stared and waited, then saw not one orange firefly but three.

After a while it was easy to know I wasn’t mistaken because the orange fireflies were mingling near the yellow-green ones. Have you ever been unsure whether a certain pair of pants were black or dark blue? What do you do to make sure? You find a piece of clothing you KNOW is black, and you put it next to the pants in question. Suddenly, they’re clearly blue, not black. It’s the comparison that makes their color clear, and it didn’t take long to confirm these were orange fireflies.

I wondered if maybe the fireflies had evolved to use orange streetlamps to hide from predators, or maybe the lightning bugs had somehow ingested manmade chemicals, which then accumulated in the insects’ light organ and changed the chemistry enough to make an orange color instead of a yellow-green one. Was I the first to see this change in the species? Or maybe I discovered a new species of bioluminescent insects that just happened to come out and glow at the same time of day in the same places as fireflies. [Ahem] No. I’ll have to keep dreaming of the day when I can name an orange-glowing-butt insect after myself.

Turns out there are more than one species of firefly. Well, a whole lot more than one. The National Geographic Society says there are about 2,000 species of firefly, and fireflies’ flashing patterns are unique to each species. Scientists aren’t certain how the insects control the on/off switch, but they do know how they glow. Fireflies take in oxygen and introduce it to a chemical called luciferin in a special organ in the bug’s rear end. The chemical reaction creates almost no heat and almost all light. We’re talking not quite 100 percent but darn close, according to the Ohio State University, which offers firefly facts online. The university’s site also says that a normal lightbulb converts only about 10 percent of its energy to light. The other 90 percent becomes heat.

But what about the color of fireflies’ glowing butts? That can range from the common yellow-green to a reddish-orange. I had no idea.

While we’re at it, here are a few other things you might not know (and I certainly didn’t know) about fireflies, from Ohio State University’s and Nat-Geo’s websites:

  • Fireflies are not flies. They’re beetles (of the family Lampyridae), and most firefly species, but not all, have wings.
  • Like humans, fireflies are omnivores.
  • Unlike humans, fireflies generally live only 2 months.
  • Some firefly species don’t glow. In the U.S., you’re unlikely to encounter the glowing types west of central Kansas.
  • Both firefly larvae and adults glow, and both taste not-so-good to predators.
  • Some Asian species of firefly live underwater, breath using a type of gills, and eat snails.
  • Fireflies live just about everywhere humans do, except for the southernmost tip of South America, most of Greenland, and the northernmost reaches of Alaska, Canada, and Russia. Also, you won’t find any fireflies in Antarctica, though you’re welcome to go there to look.

That said, keep an eye out and you just might see a firefly that’s not yellow-green. I’ve seen just three, and though I’ve kept looking since, I haven’t seen another orange one. Maybe I’ll never see another, but I’ll still remember the joy and surprise of this single occasion — one more fond memory to relish.


Antidepressants soothe anxious minnows

If you were the most common bait fish, you would be anxious too.
You would hide in dark crannies, avoiding predators. That’s what fathead minnows normally do. But a new study from Baylor University, published 7 March in Environmental Science and Technology, shows that when the rosy-silver fish get a dose of Zoloft, they develop a false sense of security. Instead of ducking for cover when it’s light, they linger in the open, unconcerned.
Drugs like Zoloft and Prozac get into rivers, lakes and streams every time people who take them flush their toilets. The drugs can have bizarre effects on fish behavior. This is not big news: as my classmate Nina Bai reported in 2008, scientists have been documenting how antidepressants impact fish for a while. Other organisms, like shrimp and mussels, are also affected. But each new study is a step toward understanding how different species tolerate different chemicals, and in what concentrations.
For the minnows, it took 3 micrograms per liter of Zoloft to dim their evasive instincts.  The concentration of SSRIs in the wastewater described in the study was 3.2 micrograms per liter. Once the drugs have made it into the water, most wastewater treatment plants aren’t equipped to filter them out.
Image credit: Ohio Department of Natural Resources, BK

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