Wicked fast

At the north end of my patio where the fence meets the wall, a tiny space only two inches/five centimeters wide and four inches/ten centimeters deep rises from the ground to the top of the fence.  It’s the space between the last fencepost and the joist.  Because it’s nestled behind a thick hedge and sheltered from the elements, all manner of critters find their way into that minuscule crevice.

I’ve been forced to evict paper wasps who wanted to nest there.  I’ve seen spiders chase each other and prey through the shadows.  I’ve watched mud daubers find the tiniest cracks where they could climb inside the wall and hide their offspring.  And the anoles long ago found they could live inside the wall by navigating through those same cracks.

Given the narrow yet deep shape of the recess, I’m often left with no option but to watch whatever is in there rather than photograph it.  Because none of my lenses fit through the opening, and having the wall on one side and the fencepost on the other makes positioning a camera an exercise in frustration.  The only pictures worth keeping are those taken by standing back and zooming into the dark abyss.

On a warm afternoon not too unlike the past few days, I noticed something hidden in that spot, something that demanded my attention.  Because whatever it was, it remained in a perpetual state of motion.  Being a fan of natural light, I fired off a few shots knowing precisely what I would get.

A blurry shot of a crane fly bouncing up and down at lightning speed (20080314_02768)

The blur does little justice to how fast this insect was bouncing up and down.  To my eye, it looked like an ethereal shadow hovering just above the wall, some dark specter made of smoke and whispers.  But don’t take my word for it.  Here’s a video to show you what I’m talking about.

Wicked fast, eh?  But blurry photos and videos don’t answer the question of what it was.  Yet the behavior and shape go a long way in answering that question.  Were I to guess based only on that evidence, I’d say it’s a crane fly.  Everything about the body matches, and crane flies notoriously use the rapid push-up maneuver as a diversion against predators.

But only a clear image of the beast would be definitive, so out comes the flash for an awkward attempt at capturing a picture.

A crane fly (20080314_02771)

Despite having to step away and zoom in just to get the flash to light up the space, it seems obvious my assumption was correct: it’s a crane fly.

I know what you’re asking.  But what about that long proboscis?  Yes, it threw me for a loop when I first looked at the photo.  Crane flies generally have a small proboscis, yet this creature has one that would terrify anyone frightened of biting insects.  In fact, it looks more like a giant mosquito with that menacing mouth.  So what gives?

Well, there’s a handful of crane fly species with the elongated proboscis.  It’s not common but it’s not unheard of.

And since its position kept me from getting any clear shots with details, I can’t pin down an exact species or genus.  Nevertheless, it was cool to watch because I’d never seen one do that at such a high rate of speed.

Oh, and I was the threat the fly was trying to confuse.  When I finally stepped away hoping it would calm down so I could get a better shot, it flitted out of the alcove and vanished in the bushes.  Just my luck.

10 thoughts on “Wicked fast”

  1. Strange that rapid bounding is such an effective deterrent to predation. l recall seeing similar behavior by a harvestman in Nebraska last fall – seems to me like it would actually draw attention, but I guess I’m not looking at things with birds eyes!

    1. I’ve always thought the same thing, Ted. When grasshoppers do their leaf sway thing, it draws my attention to them. Same with bouncing crane flies and harvestmen. Does that mean I can brag that I’m not a birdbrain?

  2. My guess was a crane fly, too, when I saw the smoky, ghostly image and then the video. I wonder if the movement was related to mating behavior (e.g., distributing pheromones) rather than being a distraction. I’ve never – ever – seen a crane fly do this. Thanks for sharing with us.

    1. I wondered about pheromone dispersal, Scott, and also wondered about temperature control. Those two ideas in addition to predator avoidance ran through my mind as I watched the fly. But when I investigated it later, the only thing I could find was that this is a typical threat distraction. Though I’ll add I didn’t have much luck finding a great deal of material on adult behavior; it made me laugh to realize there was more readily available research on crane fly spermatocyte behavior than there was on crane fly adult behavior.

    1. Thank you, Clive. I’m afraid the last month has been less than agreeable. I’m still not on top of things and am offline more than online, but I’m trying my best to catch up.

    1. Exactly right, Anna: they’re very common in spring and autumn, and despite looking like a giant mosquito, they’re completely harmless. And terribly fragile, too.

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