Monarch Butterflies: Tiny Tag, Big Discovery

Scientists have made a big step forward in tracking monarch butterflies. They are now able to follow individual butterflies on their long journeys from places like Ontario to Mexico. This is possible thanks to tiny, solar-powered radio tags that weigh just 60 milligrams. These tags are attached to the butterflies, which usually weigh between 500 and 600 milligrams. The tags are so light that it's like a half-raisin carrying three grains of rice. The tags are made by a company called Cellular Tracking Technologies. They have tagged over 400 monarchs this year. Researchers can follow the butterflies' journeys using a special app. This app shows where the butterflies are and how they are moving. The app is called Project Monarch Science, and it's free for anyone to use. The tags are a big improvement over the old way of tracking monarchs. Before, scientists would put small stickers on the butterflies. But these stickers didn't give much information. They only showed where the butterfly was tagged and where it was found. The new tags, on the other hand, show the whole journey. This is like reading a whole book instead of just the first and last pages. The tags have already shown that monarchs have amazing navigational skills. They can use the sun to guide them during the day. When it's cloudy, they switch to a backup compass that uses ultraviolet light to detect the Earth's magnetic field. This helps them stay on course even when the weather is bad. But not all monarchs make it to their destination. Only about one in four survives the journey. The rest die from things like bad weather, hungry birds, or just being too tired. The ones that do make it join huge flocks in Mexico. These flocks are so big that they can bend the branches of the trees they roost on. Sadly, the number of monarchs has been going down. In the 1990s, there were hundreds of millions of monarchs in Mexico. Now, there are usually fewer than 60 million. Last winter, there were only about 38 million. The West Coast population is even smaller, with fewer than 10, 000 monarchs last winter. The decline in monarch numbers is due to many things. Climate change is making it harder for them to find food. Deforestation and beetle infestations are threatening their winter homes. And the use of herbicides in farms is destroying their breeding grounds. All these things are making it harder for monarchs to survive. The company that made the tags, Cellular Tracking Technologies, is based in New Jersey. They make tags for all kinds of animals, from bumblebees to elephant seals. The founder of the company, Michael Lanzone, has been working on this for 20 years. He hopes that the tags will help scientists learn more about these amazing insects. The tags were first tested in Ontario, Canada. Researchers tagged 30 monarchs and were surprised to see how well they were flying. One of these monarchs, a female named LPM021, flew far beyond the known colonies. She was last seen 425 miles from Guatemala. After the success in Ontario, the company gave away more tags to researchers. Soon, the app was full of butterfly tracks. Scientists were excited to see where the monarchs were going and how they were getting there. They even had a friendly competition to see which monarch would make it to Mexico first. In the end, a monarch named JMU004 won the race. He was tagged in Virginia and made it to Mexico in 47 days. The scientist who tagged him, Leone Brown, got to share his triumph with her 7-year-old daughter. But the scientists say that the real point is not about winners and losers. It's about learning more about these amazing insects and how they survive.