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First Posted: 10/11/2010
MATT HUGHES
mhughes@www.timesleader.com
Scarlet tanagers are finicky.
The migratory birds build their nests deep in the forest, and don’t take kindly to fragmentation of the area around their nesting grounds.
Pennsylvania has the largest concentration of scarlet tanager nesting sites in the world, and if the forest is broken up with access roads, natural gas drilling pads and gas pipeline right-of-ways, we might be seeing a lot less of them.
So too could be the case with hermit thrushes, Blackburnian warblers and wood thrushes, all birds who lay their eggs in scarlet tanager nests.
Much of the debate over natural gas drilling in the Marcellus Shale has centered on human concerns like jobs, money and drinking water, but local biologists like Rick Koval of the North Branch Land Trust remind us that we are just the tip of the iceberg.
The scarlet tanager is just one case, Koval said, of how gas drilling, like all human endeavors, will create change in the natural environment we inhabit. And though the extent is debatable, it will bring change.
The impetus for change, Koval and others said, will be fragmentation. Access roads and right-of-ways will carve areas of forest into sections.
“We’re going to see an increase in edge-dependent animals, like cotton-tail rabbits, common yellow throat warblers, deer and even wild turkeys,” Koval said. “That could be welcome to a lot of hunters and trappers, but we’re changing an environment.”
Koval said other animals, like the scarlet tanager, are less tolerant of fragmentation and other associated factors, like noise from trucks and compressor stations. Those animals and others linked to them in the web of life will see a decline, he said.
Jeff Stratford, a biologist at Wilkes University, concurred.
“Animals that have a hard time crossing roads, like salamanders, will have a hard time crossing the road,” Stratford said. “A lot of birds won’t nest by the side of the road where humans are around.”
Stratford added, however, that “context matters.” Drilling on land that has already been clear cut, like a farm, will have less of an impact than drilling in a pristine forest.
Even in farmland, however, Koval said, drilling can create disruption if well pads are not replanted with the right species of plants once drilling is complete.
“Just about every disturbed area in the forest setting in Northeastern Pennsylvania has been reestablished with plants that are not native,” Koval said. “These plants, they’re so aggressive, they can out compete because there is less competition from animals that eat them and parasitic organisms.”
Koval used crown vetch, “that ugly plant that grows all along highways and has no wildlife benefit whatsoever,” as an example of the sort of plant that could be detrimental to wildlife if planted.
“If a landowner is considering signing a (natural gas) lease,” Koval said, “that’s something they might want to consider, what are they going to replant it with.”