Mexican officials are cracking down on illegal logging that threatens the winter habitat of hundreds of millions of migratory monarch butterflies, but they have yet to halt the tree-chopping completely. The government and sustainable development groups are working to promote monarch ecotourism in the nation’s central Michoacan state as a way to create jobs and encourage locals to protect the butterflies and their wintering grounds. “The butterflies are really our only source of income now, so we want to see them cared for,” said Jose Ramirez Franco, who makes a living driving tourists to a monarch reserve. An influx of tourists could take its own toll on the butterflies, and officials are working to minimize that impact.