Sunday, April 19, 2015

Life along (and in) a creek

Yesterday was a great spring day to be afield, and I was fortunate enough to be invited to help lead an outing organized by the Ohio Chapter of The Nature Conservancy. Our destination was a new TNC preserve along the banks of Little Darby Creek in Madison County. As there is no ready access as of yet, the preserve is not open to the public at this time which precludes me from identifying the site. Interest was high in this foray - organizers cut it off at 38 participants. We divided into two camps, and went our separate ways, exploring the preserve's hidden nooks and crannies. My thanks to Anthony Sasson of TNC for making me a part of the outing.

The banks and bluffs of Little Darby Creek were awash in wildflowers on this picture-perfect spring day. White trout lily, Erythronium albidum, as above, formed extensive carpets. In all, we probably saw 30 species of spring wildflowers, most of them growing in profusion.

In close on the flower of a common blue violet, Viola sororia. The purple lines at the whitened bases of the petals are nectar guides; they serve as roadmaps to entice insect pollinators deep into the reproductive zone of the flower.

Our trip was ostensibly a wildflower foray, but as often happens our interests were routinely diverted from botany. That's not to say we didn't admire and study many a plant species - we did! - but what good is knowing the names of every plant (or bird) if one has no idea how they fit into the bigger picture?

This stunning six-spotted tiger beetle, Cicindela sexguttata, succeeded in attracting out attention for some time. It was quite confiding as it hunted along a log, allowing close approach. Tiger beetles are the cheetahs of the Coleopteran (beetle) world. They hunt visually, and when the timing is right run down their prey with astonishing bursts of speed. When the unfortunate victim is seized, it is sliced and diced by those massive white mandibles.

The ornate suturing atop the skull of a white-tailed deer was worth admiring. Odocoilean hieroglyphics.

After all was said and done with the formal field trip, Anthony Sasson and I headed to another, somewhat more accessible part of Little Darby Creek. We lugged in our waders, a seine, and aquaria. After all, what would a springtime visit to the Darby be without taking the opportunity to admire some darters in their spring finery?

Stream levels were still a bit high, which made capturing fish harder than it would have been with a foot or so less water, but we mustered along. A true prize was this whopping big variegate darter, Etheostoma variatum. Insofar as these small perch family members go, this specimen was gargantuan, probably taping out at four to five inches.

Darters are the warblers of the underwater world. The males enter breeding condition in spring, and many species develop stunning coloration. Some of the various species' names speak to their showiness: rainbow darter, orangethroat darter, greenside darter, etc.

This little fish may not be clad in brilliant colors, but it is one of Ohio's rarer species and a totem speaking to the need to protect Big and Little Darby creeks. It is the endangered spotted darter, Etheostoma maculatum. Most species of darters, and this one in particular, are quite vulnerable to pollution issues and attendant water quality degradation. Its presence in the Darby Creeks speaks to the exceptional aquatic health of this stream system.

Shooting fish photos requires a lot of work. We lug small aquaria streamside, labor to catch the animals in swiftly flowing riffles, then immediately place our catches in the tanks. After shooting images - the fish do not pose very well, usually and some patience is required - the animals are immediately released back into the riffle from which they came.

I was quite excited when we trawled up this beast on one of the net runs. A monstrous looking thing indeed, it is the larva of our largest dragonfly, the dragonhunter, Hagenius brevistylus. The adult dragonfly is a remarkable animal that would impress anyone who clapped eyes on one. Large and brutish, dragonhunters often take down other large insects such as swallowtail butterflies and other dragonflies, some of which can be nearly as big as they are. Hence the name, Dragonhunter.

If I were some aquatic critter such as a stonefly larva or even a small fish, I would not want to see this face peering at me from the leafy detritus. The quarter-sized dragonhunter larvae lay in wait among debris on the stream bottom, and when prey bumbles along the hunter shoots out ejectable mandibles and seizes its victim. The experience must be akin to having a gargoyle come to life in an instant, shooting its jaws out like a jack-in-the-box, seizing you and jerking you back to be eaten.

A great day afield, and my appreciation goes to The Nature Conservancy for all that they do to conserve Ohio's biodiversity, whether it be ferocious dragonhunters or passive trout lilies.

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