Ditch full of distractions

Nature bummin’ with Kirk Gentalen—

“Our” ditch with a green frog sitting in wait

There are lots of ditches in St. George, but only one that we (the royal “we”) visit on a regular basis. I won’t give out the exact location (you know how protective ditch lovers are!), but let’s just say it’s a typical ditch—one that flows strong after a good rain but becomes a series of deepish puddles filled with some seriously mucky, algae water during drier times. In other words it gets kinda gross. It’s a smallish ditch, no more than a foot across at its widest, but we don’t hold that against it­—there is too much life there to be distracted by volume!

When times are warm and sunny, the air above the “ditchy-water” can be full of fly activity—a “fly lovers paradise,” if you will. And while there are several species of flies (Order Diptera) to be entertained by, there is one species that we actively search for, that we hope for a glimpse of (and maybe a photo or two of) and that is the “Phantom Crane Fly” (PCF). These aren’t your typical Crane Flies (Family Tipulidae)—the ones that are mistaken for huge mosquitoes when found in your house but fortunately don’t bite. Nope, these dudes get their own family (Ptychopteridae—Phantom Crane Fly family) and fly with a style and grace so unique that make them hard to mistake with traditional Crane Flies.

Phantom Crane Fly

Our local species of Phantom Crane Fly (Bittacomorpha clavipes) is quite the sight. Their heads and thorax are miniscule and unassuming, their abdomens are thin and measures a half inch if that. On their backs are a pair of shrunken wings, which are essentially vestigial—organs that have become useless over time—similar to leg bones found in snakes. What stands out with PCFs at first sight, though, are their long, thin, black-and-white banded legs. At the tip of each leg are swollen feet (tarsi) which are loaded with tiny holes called trachea. Trachea are “normally” used for respiration in insects but PCFs don’t breath through their feet (that would be weird). Instead they use the trachea to catch the tiniest of wind currents and breezes as they drift along. An insect with wings that “flies” by its feet! For maximum efficiency and flying potential PCFs fly with their six legs extended and spread wide, giving it an appearance like a flying snowflake or spider web.

In flight this leg arrangement gives PCFs a look similar to filter feeders in the tide pools, but these adults are not thinking about food. They actually lay their eggs in those algae pools, and as larvae their offspring feed on detritus in the muck before morphing into non-eating adults. So there is no chasing after prey or catching of food with those big legs, instead PCFs are floating snowflakes looking to mate. Hot action at the ditch!

The black-and-white pattern on the legs is perfect camouflage for shady habitats sprinkled with sunlight. Disappearing in and out of the shadows in flight gives these flies a “phantom” appearance and makes following them tricky to say the least and attempts to take photos turn into lessons of patience and focus. Those can be tough lessons, because PCFs aren’t the only ones living by the ditch—so many distractions!

Green  Frog

Spend some time with a ditch and you’ll realize that you aren’t alone in hunting PCFs (and the other flies in the area). A handful of Green Frogs also call the ditch home and nothing teaches a lesson in patience like watching a cold-blooded (literally), sit-and-wait predator. Daily fluctuations in PCF numbers makes one wonder how many PCFs have made their way through the ditch frog’s digestive systems. PCFs are towards the bottom of the food chain for sure, so it goes.

A Red-winged Blackbird attacks a Broad- winged Hawk.

Red-winged blackbirds sing from the tops of nearby cattails and bring food in for youngsters hidden in a nest somewhere in the thick patches of reeds. The blackbirds also announce my presence with loud alarm calls (I wasn’t even close to them, I swear!), which makes ignoring them even harder. As I try to convince the blackbirds that I mean no harm—probably would be better if I just zipped it instead of talking to them – Swamp Sparrows start to belt out their buzzy song in the “shared” cattail habitat. Swamp sparrows have a special spot in my heart and have long been my favorite sparrow (for reasons I can’t remember), so ignoring those is not an option. Butterflies and dragonflies zip around the grasses and clovers, and a river otter even crosses the ditch making its way to a nearby waterway it enters with a big splash. A Broad-winged Hawk catches a thermal above us and attracts the Blackbirds’ attention and angst. The hawk is promptly “escorted” away from the wetlands by the male of the pair. It can be hard to pick what to watch when spending time in the ditch (and beyond)!

Like so many ventures, trips to the ditch often have a goal, or “target” or two that gets you out there. In this case, the visit to the ditch was inspired by visions of Phantom Crane Flies. And like almost all adventures, the plethora of “side” activity demands observation and adds to the entire picture. We really aren’t there just to see the PCFs or the ditch—even though that would be more than satisfying. We’re there to see the habitat and learn about that “neighborhood.” All distractions are welcome in these cases!

PHOTOS: Kirk Gentalen

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