By Warren Uxley
This article can also be found in the Crawford Park District’s Winter 2013-2014 Newsletter
It was late May of this past year and I was just about to cross the Olentangy river in southern Crawford County when I heard the distinctive call of a male sedge wren. I hit the brakes, pulled off the side of the road and turned off the engine to my vehicle. This was the first time in four years that I had heard or seen a sedge wren in Crawford county and I had to investigate further.
Listed by Ohio Department of Natural Resources as a species of concern, the sedge wren is even smaller than the diminutive house wren that frequents suburban backyards. A species in decline, it’s erratic and wildly unpredictable movements make it a poor candidate for research projects: in the grant-driven, publish or perish world of modern science, few researchers are willing to invest time, grant money and risk their reputations on a species that can vanish only to mysteriously reappear several hundred miles away. The species’ history at the Daughmer Savannah State Nature Preserve is representative of sedge wren population fluctuations—six years ago five sedge wren males set up territories at Daughmer and were vigorously competing for space; a one year phenomenon, they have not been seen there since.
Named after the wet sedge meadow habitats that it prefers, the sedge wren will also thrive in seasonally moist grasslands. The lone male that I heard that late May afternoon had claimed territory within the floodplain of the Olentangy in an area dominated by prairie grasses and that is often left waterlogged after heavy rains—it’s almost ideal habitat.
Like all other wren species, the sedge wren is a seemingly tireless and very loud singer. In the following weeks I would hear its robust song every time I stopped to check on it.
Most of the sedge wren population leaves it wintering grounds along the coastal areas of the south-eastern U.S. and settles in the upper mid-west and adjacent Canada for the first of two breeding cycles. After raising a large brood—they lay an average of seven eggs—during the months of May and June, may of the birds will raise a second brood before heading to the Gulf of Mexico or the Atlantic coast. But some of the adults will raise one brood and head immediately southeast towards their winter range. (The juveniles will linger on the breeding grounds a few more weeks.)
It’s during this movement to their winter quarters that a few sedge wrens will settle in appropriate habitat in Ohio, Indiana and Illinois for the second breeding cycle during July and August. (Sedge wrens are often found at Killdeer Plains Wildlife Area in late summer and are obviously nesting there.) It is a sad commentary on the state of sedge wren research that the scenario just described is what is believed to be happening and NOT what is known with certainty. While it seems logical, there is not concrete proof that the wrens are nesting first in Wisconsin and Minnesota and then later in Ohio and Indiana.
Given the gaps in our knowledge of sedge wren natural history and the unpredictability of its movements, it should come as no surprise that there will be times when these birds will confound our limited understanding. The bird I found in late May was clearly not following the predicted pattern.
While his brethren were patrolling the wet meadows hundreds of miles to the northwest, “my” wren was in Ohio strenuously trying to attract a mate. Six years ago, the territorial males at Daughmer were also breaking the Ohio pattern of the late summer breeding cycle.
I kept a close watch on the sedge wren that had settled in the wet prairie along the Olentangy; for eight weeks he was steadfast in his efforts to win a female. Sadly, I am convinced that those efforts were in vain. It’s unlikely that I will see him again next year.