More
Archive
2017
2016
2015
 

Protecting the Baltimore Checkerspot Butterfly

by Tom Velat, Natural Resources

Working on the Baltimore Checkerspot Butterfly Project over the past several years has been a fascinating experience for me.

Baltimore checkerspots are rare in the Chicago region, and a few years back the Peggy Notebaert Nature Museum requested to use an existing DuPage County forest preserve population as a source stock for breeding and introducing the insect in other county preserves. In response, the Forest Preserve District started its checkerspot project in 2010, but as with any project of this caliber, we needed to first locate wild populations large enough to tolerate the removal of the individuals needed for breeding without affecting the greater population. To do that, we’ve been using the “mark-and-recapture” method of estimating populations.

During a sampling session, which usually lasts about an hour, ecologists capture Baltimore checkerspots using cloth mesh insect nets. At the end of the session, they identify the sex of each insect and use a fine-tipped indelible marker to delicately mark the wings of each butterfly with a code that corresponds to a unique number, a technique that scientists Paul Ehrlich and Susan Davidson published in 1960. This system allows ecologists to identify previously sampled Baltimore checkerspots during future sessions. (Studies have shown that the process does not harm the butterflies or shorten their lifespans.) Ecologists use mathematical formulas to compare the number of marked and unmarked butterflies from a sampling session to estimate the size of the population. Long-term data from these samplings can help them determine if populations are increasing, declining or staying the same.

This project has also included the restoration of Baltimore checkerspot habitat so these rare insects don’t blink out of existence. By removing thick overgrown brush and knocking back invasive plants with prescription fires, ecologists are opening up habitat where butterflies can find important native “host” plants: specific plants adult butterflies visit to deposit their eggs and developing caterpillars rely on for food. Turtlehead (Chelone glabra), fen betony (Pedicularis lanceolata) and mullein foxglove (Seymeria macrophylla) are all Baltimore checkerspot host plants, so their presence or absence can directly affect populations of this butterfly. In this sense, Baltimore checkerspots have benefited from the Forest Preserve District’s deer management program because abnormally large populations of deer can devour excessive amounts of these vital plants. But ecologists may still need to propagate these plants as well as the butterflies for the best success.

In the end it won’t be a quick process, but once ecologists begin to breed Baltimore checkerspots, they’ll be able to release adults into these restored areas over several seasons to create a self-sustaining, genetically diverse population.
Winter Biking in the Preserves
Published 12/27/2016
Forest Faves: Waterfall Glen
Published 12/20/2016
Forest Faves: St. James Farm
Published 11/30/2016
Forest Faves: Warrenville Grove
Published 11/17/2016
Partnering to Save Raptors
Published 11/3/2016
Prescription Burns
Published 10/20/2016
Forest Faves: McDowell Grove
Published 10/12/2016
Wolf Spider: Friend or Foe?
Published 9/27/2016
Asters: The Stars of Fall
Published 9/15/2016
Forest Faves: Herrick Lake
Published 8/31/2016
Forest Faves: Oldfield Oaks
Published 8/26/2016
Forest Faves: Meacham Grove
Published 8/16/2016
Forest Faves: Elsen's Hill
Published 7/22/2016
Pokémon Invades the Preserves
Published 7/21/2016
A Beaver Balance
Published 5/13/2016
Beyond the Bird Feeder
Published 4/28/2016
Fiddleheads and Fronds
Published 4/22/2016
Aging Trees Made Easier
Published 4/15/2016
Signs and Sounds of Spring
Published 4/15/2016
Down by the Old Mill Stream
Published 4/1/2016
Forest Jewels
Published 3/31/2016
If You Care, Leave Them There
Published 3/23/2016
Early Spring Plant Arrivals
Published 3/1/2016
Caution: Turtle Crossing
Published 2/24/2016
Know Your Invasive Species
Published 2/22/2016
Coyotes are Loyal to Love
Published 2/17/2016
More Trees, Please
Published 1/29/2016
Sowing Seeds in the Snow
Published 1/27/2016
Dunham Developments Detailed
Published 1/22/2016
2016 Stories
Published 1/1/0001
Share
Get Adobe Reader
©2016 Forest Preserve District of DuPage County
EMPLOYMENT   |   BIDS AND PROPOSALS   |   LINKS   |   RULES AND REGULATIONS
CONTACT US   |   PRIVACY POLICY   |   TERMS OF USE   |   SITE MAP