Monarchs Migration Through Indiana Could Be At Risk

At the Indianapolis Zoo’s Hilbert Conservatory, children delight in the butterflies.  The Butterfly Kaleidoscope features nearly 40 different kinds of butterflies, including many species found in Indiana.

Lori Rodell, the curator of horticulture at the Indianapolis Zoo. She says they like to include local butterflies to highlight the importance of conservation.

"Unfortunately our native populations are dwindling due to habitat loss and chemical useage.  People can come in here and see a vast quantity of butterflies in here where you don't see that many outside," Rodell said.

One of the most beautiful and recognizable butterfly species – the monarch – is in the midst of its spring migration north, and in a few weeks, it’s possible that you might see one in Indiana. But don’t count on it.

Over the past two decades, the monarch population has declined dramatically.  Jon Neal, Purdue University entomologist, says the monarchs’ struggle for survival may be related to climate variations like we experienced in the summer of 2012, when temperatures consistently soared into the 90s.

"That's very stressful on their food plant the milkweed. We had very very low numbers that year, I think we counted two monarch butterflies," said Neal. "I wasn't even sure we'd see one because populations were so low."

He also says that other factors in Indiana play into the destruction of the monarchs’ milkweed habitat.

"There have been some surveys that show there is less milkweed in some of the argricultural fields because of changes in herbicide use," Neal said.

Monarchs rely on milkweed for survival, laying their eggs on milkweed leaves, where they hatch into caterpillars and then feast on the plant. A substance in milkweed also makes the insects taste terrible to predators -- a good defense as they complete their transformation into adult butterflies.

Butterflies can be one indicator of an ecosystem’s health.  Every summer Purdue hosts a butterfly count where the public is invited to help count butterflies highlighting the importance of habitat conservation and biodiversity.  The event also aims to determine the health of the state’s butterfly populations.

"We can kind of see the ups and downs of different species throughout the year," Neal said, "I think it's important to monitor large changes."

Neal is hopeful that the monarchs will have a better year because the returning overwintering population has benefitted from fair weather during the current trip north.  

The monarch’s annual migration across North America is highlighted in a PBS special Wednesday, April 30 on  WFYI 1 at 9 p.m.  “Incredible Journey of the Butterflies”, from the series NOVA, documents how these creatures travel thousands of miles along the same route, including right through Indiana, every year.