“How climate change is hurting monarch butterflies”
"Most monarch butterflies spend the winter in Mexico. But the rest of the year they can be found throughout much of the continental U.S. – as long as there’s milkweed. This tall plant is the only food monarch caterpillars eat, so that’s where the butterflies lay their eggs. But Chip Taylor of the University of Kansas Monarch Watch says human development and agricultural practices, including herbicide use, have eliminated a lot of milkweed. That’s making it harder for monarchs to find stop-over sites where they can lay their eggs during their summer migration."