“Monarch butterflies get tiny trackers to help scientists follow their mysterious migration”

Key points

• Scientists attach tiny tracking devices to hundreds of monarchs to map routes.
• Solar-powered tags weigh about a drop of water and enable real-time data.
• Tracking has revealed connections between eastern monarchs and central Mexico.
• About 175 tagged monarchs have been detected in Mexico this year.
• Researchers note limitations: tags show receiver hits, not exact locations or survival.