Butterfly monitors: The new patrollers of South Patrol Road

There are about 20,000 species of butterflies, which are found worldwide except on the continent of Antarctica. At Midewin National Tallgrass Prairie, two dedicated volunteers have counted 26 species of these winged insects present at a Wetlands Initiative restoration site known as South Patrol Road.

Carol Smith (left) and Penny Vanderhyden (right) have been observing and recording butterfly data for six years at the South Patrol Road restoration site of the U.S. Forest Service's Midewin in Wilmington, Illinois. Begun in 2001, South Patrol Road was the first of The Wetlands Initiative's (TWI) six restoration sites within Midewin, where TWI partners with the Forest Service to restore the region's largest natural area.

The South Patrol Road site, named for the road along which the Army would patrol in the site's arsenal days, previously was degraded farm fields. TWI restored the natural hydrology and planted native species to create a 490-acre complex of marshes, sedge meadows, wet prairie, wet-mesic prairie, and mesic prairie. The result is improved habitat for butterflies because plant diversity attracts more species, providing food as host plants for caterpillars or nectar for adult butterflies.

Penny and Carol share the responsibilities of taking photographs and notes, posting data to websites, and attending annual meetings for volunteer monitors. When asked why they took such an interest in butterfly monitoring, Penny and Carol said that their love of nature and the history of the arsenal at Midewin attracted them. Carol also added that, since she is retired, the 11am to 3pm monitoring time is ideal for her late mornings.

A Checkered White was one of the unusual species Penny and Carol found at South Patrol Road. This butterfly typically has a more southern range.

Butterfly season spans from June 1 to August 7. The Illinois Butterfly Monitoring Network (IBMN) requires volunteers to survey their sites at least six times per season, and each visit must be 1-2 hours. Penny and Carol walk the same 4-mile route each visit, and later enter their data into the IBMN website. They are two of the nine monitors at Midewin, and their route is one of more than 100 sites throughout Illinois that are being monitored every year by volunteers. IBMN has training material on their website, and training is provided for volunteers through two events each year.

IBMN was established in 1987 by The Nature Conservancy to explore the impact of land management on wildlife. Over the years, monitoring has shown compatibility of some remnant-dependent species with a variety of land management techniques conducted by TWI and other organizations. Through analysis of the extensive database, population trends of species throughout the Chicagoland area are starting to emerge. These results will assist land managers in more effective conservation of the state's butterflies.

Penny and Carol identify butterflies by photographing them. Later, at home, they use the Internet, books, or expert sources to identify them. Their technique does not risk harming the butterflies, unlike netters, nor does it disturb their habitat. The more butterfly species that are spotted, the bigger a habitat's success rate. In 2010, there were 26 different species at the South Patrol Road site. Numbers of species increase or decrease depending on different conditions.

To Penny and Carol, weather creates the biggest variable for species variety. Heat and mildly wet conditions bring out the most butterflies. Spring to summer is the ideal time to see different species. Peak conditions are above 75 degrees with little to no breeze. Butterflies are cold-blooded and will not fly if the temperature is below 50 degrees. In addition, extreme heat may harm the eggs, larvae, and adults.

Penny and Carol noticed that the butterflies tend to congregate in short grass and gravel. They are also spotted in large numbers among rain puddles (a behavior called "puddling," in which they drink up salts and nutrients) and cow manure. In their six years, Penny and Carol have seen seasons where species numbers are lower and other seasons where the numbers are higher. Overall, the species numbers have increased in their time volunteering. Depending on the amount of Skipper butterfly species seen each season, the total number of species ranges from 20 to 26.

Penny and Carol called spotting hundreds of Monarchs hanging together in trees "a sight like no other."

This year, the ladies made a unique find while monitoring. They spotted a Checkered White butterfly, which is commonly found further south. Its presence may be an indication that weather further north is starting to get just as hot as in the south and suitable for southern species.

They have also seen other rare species for the area like the Giant Swallowtail and the Cloudless Sulfur. Once, they spotted hundreds of Monarchs all hanging in a group of trees, which they described as a sight like no other. Some of their photos may be seen on IBMN's website and Facebook page.

Penny and Carol each received the Ecological Monitoring Volunteer Award from Midewin National Tallgrass Prairie in 2011. They are very proud of this award because their work has been recognized and they are making a difference in the ecological community. They have their awards on display in their homes to remind them that their efforts do not go unnoticed and that they are important to the Midewin volunteer program.

More information:

  • Click here to visit the Midewin volunteer website, which includes details about volunteer opportunities.
  • Click here to visit the butterfly monitor volunteer site.
  • Visit the IBMN Facebook page.
  • Click here for other ecological monitoring opportunities. 

Lara is an Environmental Science major at Lewis University. She is interning this summer with the Wetlands Initiative through the Associated Colleges of Illinois' Conservation and Green Jobs Internship Program.