Last month I visited a friend in Springfield, Ohio. Driving out from Chicago, I chose not to take the Interstate, and took smaller roads instead. Coming in from the northwest, entering Logan County, I recalled that there had once been a Hine's emerald dragonfly locality nearby.
The next morning I found time to go online and do a little searching. My memory had been accurate; the type locality had been in Logan County, near Indian Lake. That's about all I was able to find without getting back to my files which were 2,000+ miles away. So at the end of the trip, I did enough recon to get a sense of the land north of Springfield (more on that later) and filed it away for future action.
This morning at the office I was working on an entirely different aspect of the Hine's emerald dragonfly, which is a federally endangered species. Mostly it was number crunching, calculating density estimates for a major field study I'd led in Illinois over the summer. There, a dozen or more Hine's emerald dragonfly populations persist while in Logan County Ohio no one has seen the species since 1930. However, in writing up a tech memo with todays analysis, I had occasion to pull out the original description of the species, published in 1931.
In that paper, E. B. Williamson provides an unusually thorough description (for that time) of the type locality. He says:
“Ohio State Road Number 117 crosses the North Fork of the Little Miami River north of Huntsville, Ohio. The North Fork is a small stream at the bridge, only a few feet wide and at the season we were there carrying but little water. From its source a mile or two above the bridge it meanders through open and pastured fields in an almost flat terrain of clay soil. Below the bridge there are some willows, adjacent thickets, a few trees, and long, dense growths of lizard-tail through which the water winds its way, often concealed by the abundant vegetation. This condition passes abruptly after about a quarter of a mile into a deep dredged channel about 20 feet wide, which extends into Indian Lake. The upper end of the dredged channel, possibly a quarter to a half mile in length, is in heavy swamp woods, winding through which is the old channel of the creek, now reduced to pools of greater or lesser length.
In this woods is a heronry which Professor Hine visited on June 7, 1929. Leaving the woods along its northern side where it adjoins a golf course, he saw a dragonfly hovering two or three feet above the ground in an open spot under a bush."
A week later, James S. Hine and C. H. Kennedy returned to the site:
“The day was rainy and apparently unfavorable. They failed to find any Somatochlora in the woods, but on visiting the dredged channel they were able to take five specimens resting on low bushes on the wood’s side of the high bank of earth thrown up by the dredge when the channel was dug."
A total of six specimens were collected in 1929, and only one in 1930 despite searches by a larger group. It appears that the dredge activity had recently disrupted the habitat, and that the collectors found the final remnants of a dying population.
On a 2006 Google Earth photo, the type locality is easy to locate. There is now a dredged channel to a point well above the bridge. North of the stream and west of SR 117 is a residential subdivision, and across from this is a narrow wooded band and then open farmland. Downstream is an extensive woodland extending all the way to Indian Lake, and within the woodland several old channel scars are visible. Depending on which channel was active in 1929, the specimens were collected either near the subdivision-woodland boundary, or a short distance into what is now woodland. There is currently no evidence of a golf course, although it’s possible that the subdivision occupies the former location.
Here's what I'm able to determine from Williamson's description, a look at that Google Earth photo, and (just now) a look at a detailed surficial geology map of the region:
The site is associated with the headwaters of the Great Miami River drainage, and specifically with the north fork;
Most of the surrounding land has been dramatically altered, with the possible exception of some woods on the downstream end that don't appear to be of very good quality;
The North Fork appears to be much more extensively dredged now than in 1930;
As with most other known Hine's emerald dragonfly localities, the site is underlain by dolomite bedrock. Unlike most of those other sites, at the Logan County locality the bedrock is covered by anywhere from 150 to 250 feet of glacial till, outwash, and alluvium;
Sand and gravel outwash deposits just north of the channel appear to be the most likely source of groundwater, however the site appears to be relatively level;
Organic deposits are prevalent between SR 117 and Indian Lake in the vicinity of the channel, with alluvium up channel and till to the south;
There is no evidence of suitable remaining habitat anywhere in the immediate vicinity of the type locality.
Chasing down additional detail would most likely require a return visit to Ohio. The oldest photos I can find online date to 1994, and these show conditions similar to those in the 2006 photo mentioned above. Normally, air photos are available from as early as the mid to late 1930s, and getting a look at these, and at any slightly older maps of the area, would be among the highest priorities to reconstruct historic conditions. Of course, there's no substitute for actually walking the land.
What little I've learned thus far has raised some interesting questions. First, this place is quite different than the other populations I've visited. Understanding the type locality may shed light on the overall habitat requirements of the species, and may assist with restoration efforts elsewhere.
Would restoration be possible at the type locality? In theory, probably. In practice, any serious attempt to restore hydrology might very well flood the adjacent subdivision. There is also, as far as I can tell, no publicly owned land to start from. Then there are the genetic issues, with the nearest source populations hours away by car.
Next, some thoughts on what I saw during my too-brief visit to the area. In the meantime, there's more on the Hine's emerald dragonfly on
my web site