PLAIN GROVE TOWNSHIP, Pa.– They crept through the mist covered Black Swamp of Lawrence County creating wet sucking sounds as they trudge forward. The muddy squelches added to the natural soundtrack of bird songs and frogs croaking. The Red-winged Blackbird calls skipped across the wetlands bouncing off the peeping mating calls of recently thawed amphibians. The voices of Wood Frogs and Cope’s Gray Treefrogs folded over the lower bass of Bullfrog croaking.
The swamp is teaming with small frogs—enhancing what is a breeding habitat for some migrating avian species. As we transition into the first days of a new season, the marsh will swell with tadpoles and insects. The fish, invertebrates and other organisms offer a robust menu for a variety of animals.
The frog population is preparing to mate during these first warm days of spring will offer a reliable food source for the larger returning waterfowl. The creatures of the mud and water are just some of the items of the omnivore’s menu; at least until the season delivers more plants and invertebrates. Small amphibians can make up part of the diet of Mallard and Ring-necked Ducks, Canada Geese and Sandhill Cranes, all on our birding list for the day.
Mapping out the neighborhood
We selected the Black Swamp and Volant Strips as our birding destination because the e-Bird database provided recent reports of Sandhill Cranes in Plain Grove Township. This area of private property and game lands runs about a mile in each direction. It networks grasslands with a localized series of marshes that connect into Mercer County (where it is called the Pennsy Swamp). The Volant Strips and Black Swamp are listed as an Important Bird Area (IBA) by the National Audubon Society. An IBA is a vital migratory ground for songbirds and waterfowl while also serving as a winter home for other species.
The Pennsylvania Society of Ornithology (PSO) describes this area as one of agriculture sites and wetland areas reclaimed from coal strip mines. The PSO reports the area is now home to a variety of sparrows and raptors that include Short-eared Owls. The game lands are also home to waterfowl, including the Sandhill.
On our drive to the Black Swamp we traveled by farms and industrial sites, including an active mining operation. The Pennsylvania Department of Conservation and Natural Resources lists the Plain Grove Sand and Supply Company as the local operator. It’s just one of dozens of active mines in Lawrence County. The Plain Grove plant manufactures sand products. Other mines in the county currently process everything from construction sand, limestone, clay and coal to metals like cadmium, copper and cobalt.
The juxtaposition of this IBA and the industrial and agricultural operations seems contradictory. A spill or misstep in surface mining operations could contaminate the water quality of the marshes. Heavy rain could also push pesticides and fertilizers from ag sites into the runoff feeding the Black Swamp. However, for now it would seem all is well and the swamp’s wildlife appears to be thriving.
I observed sections of what appeared to be a tributary into a larger marsh with orange muddy sediment and discoloration. As a native West Virginian, I have seen this too many times. It would appear to be evidence of acid mine drainage. I grew up hunting and fishing in the Mountain State and I saw scenes like this all too often and on a much larger scale. I can only speculate that this patch inside the Black Swamp is the result of drainage from the old strip mine. A water quality test could easily determine the chemistry of this water.
Perhaps the depressions in this part of the swamp have evolved into a filtration system capturing and filtering the sulfides released from the old mining operations. The spring rains could also help dilute the acid levels to neutralize the contaminated water as it mixes into the wetlands.
Expansion of the Sandhill Crane
Patience pays off for our birding group when we situated ourselves along the shoreline of a shallow body of water. We were surprised by a loud, vibrating clamor that sounds something like an off-key plastic toy trumpet. The call was quickly repeated. Our guidebooks confirmed this was a mating call for the Sandhill. While we strain our eyes through the binoculars, the common cattails obscured any view of the cranes. The brief call of the Sandhill was replaced by geese and ducks flying overhead.
According to the Pennsylvania Game Commission, the Sandhill Crane has only recently taken up part-time residency in this region. However, you will find massive flocks featuring tens of thousands of the cranes west of the Mississippi, particularly in the Great Lakes region and parts of Canada. Wetlands along the Platte River in Nebraska are a popular destination to watch these flocks.
Eventually we move back to the Volant Strips portion of this IBA and we spot a small flock of Sandhill Cranes. They’re in a freshly plowed field next to large grain silos situated across the road from what appeared to be a conveyor belt for the sand plant.
Here, in the middle of industrial and agriculture activity, we witness these large, gray-bodied, gangly crimson-capped birds. A dozen sifting through the tilled soil for bits of grain, probably corn, and possibly an occasional toad.
The Volant Strips and Black Swamp habitat is clearly a mix of marsh, grasslands and surface mining operations to create an odd balance for the crane. We witnessed their feeding in the field for cultivated grain. The Audubon Society reports they will eat large amounts of it. In Lawrence County, farmers produce heavy amounts of corn along with soybeans, wheat and barley. The rich wetlands and nearby woods will also serve a diverse population of wild plants yielding roots, seeds and berries. This area is also home to scores of amphibians, snakes, rodents and nestling birds. In a nutshell, if the cranes can eat it, they probably will. The Sandhill is identified as an opportunistic species.
The Sandhill flocks migrating here are small. They can’t compare to the scale found to the west. State game biologists have documented the crane is breeding here, offering proof they are expanding into parts of western Pennsylvania. Our observations add to that body of evidence that the species is making this IBA a migration destination.
Some of the species we checked off our list during the our Black Swamp & Volant Strips excursion:
- American Coot
- Red-winged Blackbird
- Red-tailed Hawk
- Sandhill Crane
- Mallard Duck
- Rink-necked Duck
- Morning Dove
- Northern Mockingbird
- Red-bellied Woodpecker
- American Robin
- Song Sparrow
- Northern Cardinal