Imagine that the city of Los Angeles had shrunk to the size of the town of Monterey. You’d be shocked. Basically, that is what has happened to the monarch butterflies that overwinter in California. At Thanksgiving 2018, the population of western monarchs hit a record low of less than 29,000 butterflies, a decline of 99.4% since the 1980s, when the number of monarchs flying to California for the winter is estimated to have been 4.5 million. For every 160 monarchs there were 30 years ago, there is only one left flying today.