The term “share the trail” is taking on new meaning at Centennial Park with the addition of new signs to warn bicyclists to be on the lookout for Franklin’s ground squirrels.
The species is threatened in Illinois, and a colony of the reclusive rodents live in the tall grass along the south end of the Sangamon Valley Trail in and near Centennial Park.
The squirrels cross the trail to get to different areas of grassland, which is why researchers at the University of Illinois Springfield have teamed up with the Springfield Park District to put up the warning signs along the trail.
Already this year, the UIS researchers have discovered the carcasses of two Franklin’s ground squirrels that were apparently hit by bicyclists. One of the dead squirrels was pregnant.
“Their average litter size is up to seven pups,” said Tih-Fen Ting, an environmental scientist at UIS.
“If you take out one reproducing female, you are seeing potentially seven fewer squirrels. We just want people to slow down and pay attention. Also, we are seeing increased usage and traffic on the bike trail. That’s another reason we want people to be careful.”
Juvenile male Franklin’s ground squirrels leave the colony when they get older and head out to find females in another colony. Due to habitat loss and habitat fragmentation, they don’t always find a new home.
Ting’s current study started in 2013, and during that time, she hasn’t recorded a single new male originating from a different colony and finding the colony near Centennial Park, or any of the Centennial Park juvenile males finding another colony.
There is another colony south of Chatham, but so far, there is no evidence that the two groups intermingle. That means some of the males are staying where they’re born and there’s a danger of inbreeding at both sites. Inbreeding isn’t good for the overall health of the colonies.
As far as Ting can tell, the males that leave the Centennial Park colony either fall victim to predation or are they hit by a car as they look for another colony.
“Last year, we had three males dispersing beyond Curran. We tracked them all the way toward New Berlin down Old Route 54,” Ting said.
Unfortunately, the squirrels met the same fate as the other male juveniles that left the Centennial Park area in search of a mate.
“They died. They died as bachelors,” Ting said.
So far this year, Ting and the other researchers have trapped 53 individuals at the Centennial Park site, including the bike trail.
That’s down from 68 last year and 84 the year before.
Ting is trying to find out why the numbers are falling.
“I suspect the local population has become isolated,” Ting said.
As far as researchers know, the colony of Franklin’s ground squirrels along the Sangamon Valley Trail is densest colony in the state.
There also are documented Franklin’s ground squirrel colonies at the Barnhart Prairie Nature Preserve near Urbana and an abandoned railroad bed in Vermilion County.
Previous attempts to release Franklin’s ground squirrels into reconstructed Illinois prairies were not successful. That’s one of the reasons it’s important for bicyclists to keep an eye out for the squirrels when they are riding near the park.
Dog owners also are being asked to take extra care.
Ting said she’s grateful for the park district’s help in putting out the signs and also for limiting mowing to preserve the tall grass.
“They are very responsive,” Ting said of the park district.
Leslie Sgro, president of the Springfield Park District, said the district has a role to play in both recreation and conservation.
“We have 75 acres of wild prairie in part to help the ground squirrels thrive. That was intentional,” Sgro said.
“We love beautiful open spaces and we love all of the critters that thrive in those spaces. In any urban or suburban environment, it’s really important that as we grow as a community, we make sure that there are beautiful spaces not only for the people, but also for the animals that live there.”
The warning signs near Centennial went up about a month ago. There also are dispensers on the signs that hold information brochures on the Franklin’s ground squirrel.
Ting has already gone through about 300 brochures, which she sees as a good sign.
This article appeared in The State Journal-Register on October 8, 2017.
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Video from The State Journal-Register.
