Scientists Express Concern Over Dwindling Number Of Migrating Monarch Butterflies

Every year, monarch butterflies journey from Canada and New England all the way to Mexico.

It's an ecological wonder. But scientists are worried as they've recently noticed a dip in the number of butterflies making the trip.

Some say climate change and severe weather could be threatening the migration. Also, what's been seen as the primary driver is a lack of milkweed plants — vital food for the butterflies.

But as WNPR reporter Patrick Skahill tells Morning Edition, a controversial new paper is questioning that theory.