(BLOOMINGTON) - All trees greater than 3 inches in diameter that must come down for construction of I-69 must have been cut by now. Those that weren't will have to wait until October to be felled - because of a bat.
Female Indiana bats, a species on the federal endangered species list, give birth to their pups under loose bark on big trees between April 1 and Sept. 30.
This time of year, female bats form maternity colonies - about 100 bats each - under the loose bark of old trees, said Lori Pruitt, the endangered species coordinator for the state of Indiana for the U.S. Fish and Wildlife Service, based in Bloomington.
Fourteen such maternity colonies have been found along the route of I-69 in Indiana, including four in Section 4, between Bloomington and southeastern Greene County, according to the highway's final environmental impact statement.
"By the deadline of April 1, we will have removed all trees 3 inches in diameter or larger that need to be removed for construction purposes on the contracts that have been awarded," said Cher Elliott, spokeswoman for the Indiana Department of Transportation.
Two of six contracts for the highway have been awarded in Section 4 so far.
"As well, by the deadline we will have cut trees 3 inches or larger that need to be removed for the data collection process for geotechnical information on unawarded sections," Elliott said.
She said work on the last parcel was started Thursday.
Elliott said the tree-felling deadline was determined by the Indiana Department of Natural Resources, and construction work will follow those guidelines.
"You can't look at a tree and tell if it has bats in it," Priutt said. Thus the need to avoid cutting any trees after female Indiana bats start establishing maternity colonies, she said.
According to the environmental impact statement for the highway, "Seasonal tree-cutting restrictions will ensure no direct impacts/take occurs from the construction of I-69 during the maternity colony season. INDOT has also extended this restriction to include all borrow areas used by construction contractors."
"To avoid any direct take of Indiana bats, no trees with a diameter of 3 or more inches will be removed between April 1 and September 30," the EIS states. "Tree clearing and snag removal will be kept to a minimum and limited to within the construction limits. In the median, outside the clear zone, tree clearing will be kept to a minimum with woods kept in as much a natural state as reasonable."
The plan for I-69 includes tree planting and creation of new habitats for the Indiana bat, including acquisition of 36 properties encompassing 2,636 acres of forest preservation and more than 1,168 acres of reforestation, according to the EIS.
Pruitt said female Indiana bats return to the same area each year to give birth, but not necessarily the same tree.
"You can't count on dead trees lasting forever, or bark might fall off, so they do move around." Pruitt said. "Typically, a maternity colony will have a number of primary roost trees, where most females congregate, and an even larger number of secondary trees where some bats will be some of the time."
She said bat pups can't fly for a month, and at birth, they weigh about one-fourth as much as their mother.
"In dire circumstances, a female will fly with her pup, but it's not easy," Pruitt said.
The U.S. Fish and Wildlife Service estimated the global population of Indiana bats at 424,708 in 2011, with 52.5 percent counted in Indiana. The bats were tallied while hibernating in caves during the depths of winter.
Only about 10 percent of the species' maternity colony areas have been found, Pruitt said.
She said in 2007, 269 maternity colonies were found, and 80 were in Indiana.
"We don't know where most of them are in summer. We know where some are," she said.
The I-69 environmental impact statement quotes the U.S. Fish and Wildlife Service regarding the highways's threat to the Indiana bat: "The proposed extension of I-69 from Evansville to Indianapolis will have greater impacts to Indiana bats than were originally considered," but the project "is not likely to jeopardize the continued existence of the Indiana bat and is not likely to adversely modify the bat's designated Critical Habitat."
Even though tree cutting for I-69 will stop as of today, there is still work that can go on in segments where construction contracts haven't been awarded yet, Elliott said, including utility relocation.
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