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EIU Research Projects

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UBI conducts studies with Eastern Illinois University student collaborators as part of their university education.

Female Eastern Tiger Swallowtail Study

EIU Collaborators: B Ozier & P Switzer

Yellow color morph of female Eastern Tiger Swallowtail (Papilio glaucus)

female dark form Eastern Tiger Swallowtail on mountail mint.jpg

Dark color morph of female Eastern Tiger Swallowtail (Papilio glaucus)

Even though they look so different, both of the butterflies shown above are female Eastern Tiger Swallowtails!


Using iNaturalist observations, this study examines two aspects of the behavior and evolution of Eastern Tiger Swallowtails (Papilio glaucus) in Illinois, focusing on the yellow and dark forms of the females. This species is interesting because although all the males have the familiar yellow wings with black stripes, only some of the females share this yellow coloring. Other females have no yellow at all.


These "dark-form" females are thought to be one of the mimics of the toxic Pipevine Swallowtail (see our Large Dark Butterflies page for more about that!). The wing color of the females is a genetic trait passed down from mother to daughter - all daughters of a dark-form female will also be dark-form and vice versa. All the males have yellow wings, though, even if their mother was a dark-form female.

The first aspect of this study relates to what the butterfly is perched on in the photo of its iNaturalist observation. Males of many butterflies get salts and minerals from damp soil with a behavior called "puddling". They give much of these gathered nutrients to females during mating, which enhances the survival of the female and the eggs she lays. Can we detect behaviors like puddling simply from looking at photos submitted to iNaturalist? Is there a difference in the proportion of observations of yellow-form females, dark-form females, and (always yellow) males seen on flowers as opposed to resting on something else (like the ground or a tree leaf)?

The second aspect of this study focuses on the dark-form and yellow-form Eastern Tiger Swallowtail distribution throughout the state of Illinois, compared to the distribution of Pipevine Swallowtails. Does the percentage of dark-form vs yellow-form female Tiger Swallowtails in an area correlate to how prevalent Pipevine Swallowtails are in that area, or is the percentage always the same no matter how many Pipevine Swallowtails there are? When are the first and last yellow-form female, dark-form female, and male Eastern Tiger Swallowtails seen in an area each year (their seasonality)?

This study aims to shed some light on these and other fascinating questions about the behavior and evolution of this popular butterfly.

Butterfly Hotspots vs Turf Grass Lawns

EIU Collaborators: E Apoduca, E Bollinger, T Funk, L Grindley, G Hofmann, K Montemayor, P Switzer, T Tarquin

Painted Lady and Common Buckeye on New England aster at a UBI Butterfly Hotspot

Large expanse of mowed turf grass lawn

The two photos above depict quite different urban habitats. This study was conducted to determine the effects of these two landscaping choices on the diversity and total number of butterflies using the areas.

Over 40 million acres of turf grass are estimated to exist in the United States. This type of habitat is typically poor in biodiversity, which is one reason organizations such as the Urban Butterfly Initiative promote the inclusion of native plant landscapes in urban areas whenever possible. To examine the effectiveness of these native plant habitats, this study compares the diversity and abundance of butterflies in the butterfly landscapes established by the Urban Butterfly Initiative in Charleston, IL, versus nearby turf areas.

Keeping in mind the effects and repercussions of our landscaping habits, communities and societies must decide what values are most important and perhaps change our perception of what constitutes "good-looking" landscaping. For links to native plant and landscaping resources, see our Butterfly Plants and Landscaping page.

"Do the best you can until you know better. Then when you know better, do better." - Maya Angelou

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