Experts hope for no disruption of hibernating bats during important population count

Shauna Marquardt of U.S. Fish and Wildlife Service stands by one of the Sodalis Nature Preserve gates during a visit to Hannibal last March. She will be in Hannibal this week to participate in a bat survey.
Posted: Feb. 7, 2017 4:39 pm Updated: Feb. 7, 2017 4:42 pm

The sleeping inhabitants of the Sodalis Nature Preserve in Hannibal are scheduled to be counted this week. And if things go as planned on Thursday the hibernating bats will never know they had visitors.

While collecting accurate information from which an accurate total will later be derived is critical, of equal importance is not disturbing the wintertime occupants of the former Marblehead Lime Company mines in southern Hannibal.

"We don’t want to have any undo harm in collecting this data even though this data is very important," said Shauna Marquardt of U.S. Fish and Wildlife Service. "We want to make sure we’re not doing more harm than good collecting that information."

To minimize any potential disturbance, talking among the members of the survey teams will be kept to a minimum once they enter the mines. Lights will be shined on clusters of bats for only short periods of time. Surveyors will also be asked to get no closer to the bats than is necessary to discern individual animals in a cluster.

Shelly Colatskie of the Missouri Department of Conservation doesn’t know what will be revealed by the first bat census conducted at Sodalis since 2015.

"Two years ago we had 165,000 Indiana bats when we didn’t get the full place surveyed either, so we probably missed a lot. I’m hoping we find just as many or more this year, but with White Nose Syndrome there’s always a chance we’ll find fewer bats," she said. "I’m trying to stay positive and hopefully we’ll find just as many, if not more, Indiana bats."


Time increase

Marquardt predicts more bats will be counted because the amount of time the census-taking personnel will be spending underground is being increased.

"We’re going to survey for four hours instead of three hours because we weren’t able to get as complete of coverage as we wanted to two years ago," she said. "I would be pleased with holding steady with our (bat total) numbers. That would be the best-case scenario, that we weren’t seeing declines because of White Nose Syndrome."

While the additional hour will allow more territory to be surveyed, not every inch of the 17-mile mine system will be covered.

"We focus on the areas where we know that bats roost," said Marquardt, noting that there is evidence that confirms some bats return to approximately the same spots in the mines each winter. "I would say we will probably cover 85 percent of the mine by the time that all eight teams spread out. It’s a big effort."

To help complete the census will be a fully-staffed survey group, who will be dressed in white suits, made of a plastic-like material, that will cover their regular clothing.


High interest

"I think there’s going to be between 30 and 35 people," said Marquardt. "It hasn’t been a problem putting the survey together for Sodalis."

"They will have a bunch of scientists from all over the country to do this major survey," said Andy Dorian, director of the Hannibal Parks and Recreation Department, during the December meeting of the Park Board. "It’s a really big deal because it will be the first time they’ve gone in to count the bats since the gates went in."

Colatskie and Marquardt have been in the Sodalis mines before. Both women are looking forward to returning and participating in the upcoming count.

"It’s always an interesting place to go in," said Marquardt.

"It’s definitely a good experience organizing a lot of folks to come and do the survey," added Colatskie. "It’s a large process, but it’s always fun."

The Sodalis survey will represent a reunion of sorts for a group of people who share a common interest in the wellbeing of bats.

"We have a lot of people that come in to Hannibal and sometimes this is the only time when we see some of these colleagues," said Marquardt. "There’s a lot of teamwork involved in this so it always feels good when the survey goes well."

Results of the Sodalis bat survey will be posted online this summer, according to Marquardt.


Reach reporter Danny Henley at

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