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A Talk on the Wild Side.

Service Programs, Partners Join Together to Save Iowa Pleistocene Snail

Iowa Pleistocene Snail
The Iowa Pleistocene Snail. Photo Credit: Lisa Maas/USFWS

The latest issue of Fish & Wildlife News features several stories on our work across programs and with outside partners to conserve the land. As Jude Smith, the manager of a complex of national wildlife refuges in New Mexico and Texas and one of the focuses of a story in the News, put it: “Whatever we are doing on the refuge complex, I’m considering how we can take the benefits and knowledge we have gained to surrounding landowners on the larger landscape. This complex is too small to make the big difference for wildlife that we are after.” More than 70% of the land in this country is privately owned, so we look beyond our borders to conserve wild things and wild places. In the magazine, Lisa Maas, Tamra Lewis and Drew Becker tell you about this collaborative effort to recover the Iowa Pleistocene Snail.

A Snail’s Journey to Recovery

Ready.  Set.  Search!  The snail technicians begin a timed search, rifling through leaf litter in front of cold air vents on a steep hillside.  Some wear gloves to protect fingers from stinging nettles and cold air blowing out of the vents.  One dons a headlamp to get a better look inside a deep vent.  “Found one!” another yells, excitedly.   

They are on an ecological treasure hunt to find the elusive and federally protected Iowa Pleistocene snail.  Their work is part of a cooperative recovery effort between the Rock Island Ecological Services Field Office and Driftless Area National Wildlife Refuge.  Their goal:  to recover the snail, a species reminiscent of another age. 

snail researchers
Snail technicians on the hunt. Photo Credit: Lisa Maas/USFWS

Federally protected as endangered in 1978, the Iowa Pleistocene snail is a glacial relict with fossilized specimens dating back 400,000 years.  Once assumed to be extinct, live snails were discovered in 1955, and now work continues to recover the species. 

The snail needs the cold soil of the “algific talus” slopes of Northeast Iowa and Northwest Illinois. Algific (meaning cold-air producing) talus (meaning loose rock) slopes are a unique ecosystem occurring in the Driftless Area of the Upper Midwest, so named because the area remained free of glacial “drift” during the last ice age.  The absence of glaciation is evidenced by the deeply carved topography and diverse habitats found in the area including cold water streams, bluffs, springs, sinkholes, caves, hill prairies and the algific talus slopes. 

With vents on the slopes that blow out cold air throughout the summer, “You can go there on a 90 degree summer day and feel 40 degree air blowing on your face,” says Service biologist, Lisa Maas.  “It’s natural air conditioning and is responsible for the cold-soil microclimate that has enabled the snail to persist for eons.” 

The recovery effort was made possible by the Service’s Cooperative Recovery Initiative (CRI). With nearly 300 protected species in or around refuges, the Service uses the CRI to support a strategic approach to endangered species recovery on refuges and their surrounding ecosystems. The CRI builds on the Service’s Strategic Habitat Conservation approach, and combines the resources of many Service programs to complete critical on-the-ground conservation projects that provide the greatest conservation benefits to the country’s most imperiled species. 

The snail is not the only unique species occurring on these slopes.  Northern monkshood, a federally threatened plant, golden saxifrage, an Iowa State listed species, and species that typically occur farther north, such as Canada yew and yellow birch, are also found on the slopes.  Monitoring and recovery efforts for the snail contribute to the conservation of these species and this unique ecosystem as well. 

“We are close to meeting the recovery criteria for the snail,” says Drew Becker, another Service biologist.  “Meeting the criteria for reclassifying to threatened status is definitely within our grasp.” 

“To delist the snail, we must document stable or increasing populations at 24 permanently protected sites, and the protected sites must be geographically distributed across the snail’s range.” Maas adds.  “To reclassify to threatened status, we must document stable populations on 16 permanently protected sites.” 

The technicians have confirmed live snail presence at 11 permanently protected sites.  They have found shells at an additional seven.  

“We found over 30 old shells at two of the protected sites,” says Tamra Lewis, one of the snail technicians. “We’re confident live snails are there, we just haven’t found them, yet.” 

snail researcher

Snail technician Amber Rodgers searches for Iowa Pleistocene snails. Photo Credit: Lisa Maas/USFWS

By searching for new snail colonies on already protected algific talus slopes,  the snail team hopes to find six new colonies, as well as find snails at the sites with shells, to achieve the 24 protected sites needed for delisting.  

The team is also working to find snails on historically occupied sites.  At one time, the snail occurred on 36 sites on 31 geographically discrete slopes.  However, live snails have not been found on many of these sites for decades.  Of these, 24 are permanently protected; the remaining 12 sites are on private property.   

The technicians have searched 84 slopes for new colonies in addition to monitoring 34 of the historically occupied snail sites.  Using monitoring protocols modeled after the plan for the Magazine Mountain shagreen (the first invertebrate to be delisted because of recovery), the technicians use timed, visual encounter surveys to quantify snail searches. 

“We use a Trimble GPS unit to collect the data,” says snail technician, K.J. Passaro.  “We measure vent temperature, soil moisture and time to first encounter of live and dead snails.” 

Adds Amber Rodgers, another technician: “It’s been an adventure. We’ve canoed to sites, forded streams, climbed steep slopes, met with private landowners, and seen a hypomelanistic rat snake,” a  rat snake with little black pigmentation. 

Their adventures receive broad praise.

“We all agree that our technicians are superstars,” says Becker.  “We only need to find live snails on five more protected sites in order to meet the recovery criteria for downlisting.  Their work far exceeded initial expectations, allowing 2015 efforts to focus on areas where we’re most likely to encounter live snails,” such as the seven sites where shells but not live snails have been found. 

The success of this recovery effort has also drawn on partnerships.  The team worked with the Iowa Natural Heritage Foundation (INHF) to hire the four snail technicians.  The foundation’s commitment to conservation, combined with its flexibility and passion for the Driftless Area of northeast Iowa, has paid dividends. 

“The Iowa Natural Heritage Foundation and the Service share the common goal of endangered species recovery,” says Kraig McPeek, field supervisor of the the Rock Island Field Office.  “They are a true friend to conservation, and we appreciate having them in our corner.” 

The feeling is mutual. 


Read more stories about the Service in the latest issue of
Fish & Wildlife News.

“Our partnership with the USFWS, whether it is with the Iowa Pleistocene snail or Topeka shiners, furthers the USFWS’ mission and INHF's mission to protect and restore Iowa's land, water and wildlife.  Overall, great conservation is happening in critical areas, and we’re proud to be part of USFWS projects,” says Erin Van Waus, land stewardship director at the foundation. 

The Jo Daviess Conservation Foundation worked with a private landowner in Northwest Illinois on an easement for a key, historically occupied site.  The permanent protection of this site achieves the sufficient geographical distribution requirement of the recovery criteria.  

Kevin Roe, a researcher at Iowa State University, is conducting genetics research on the snail by extracting DNA from slime trails left by live snails on special paper.  This research will determine effective population sizes of snail colonies, the genetic relatedness of snails within and across colonies, and will inform future management activities.  The snail technicians collected some of the DNA samples. 

“This project is a prime example of how significant progress can be made by talented, dedicated professionals through partnerships and a little extra funding,” says Driftless Area Refuge Manager Rich King. 

If the delisting criteria is met, and the Service decides to move forward with a delisting package, the Iowa Pleistocene snail could be the second invertebrate species removed from the list of federally endangered species because of recovery. 


Drew Becker, Rock Island Ecological Services Field Office, and Tamra Lewis and Lisa Maas, Driftless Area National Wildlife Refuge, Midwest Region

Just curious if you would want to know that I believe these live on my property in Rural Washington county . . . I have photos :-)
# Posted By Rebecca Barjonah | 3/15/18 6:25 PM

I live in arizona and these snails are destroying my lawn and every plant in my yard, want some to save before i kill them all?
# Posted By Davis Baker | 7/29/20 6:24 AM

Hi, the Iowa Pleistocene snail needs the cold soil of the “algific talus” slopes of Northeast Iowa and Northwest Illinois.
# Posted By Fish and Wildlife Service | 8/4/20 1:30 PM
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