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Monarch Butterfly Numbers Plummet 86 Percent In California (usatoday.com)

An anonymous reader quotes a report from USA Today: The number of monarch butterflies turning up at California's overwintering sites has dropped by about 86 percent compared to only a year ago, according to the Xerces Society, which organizes a yearly count of the iconic creatures. That's bad news for a species whose numbers have already declined an estimated 97 percent since the 1980s. Each year, monarchs in the western United States migrate from inland areas to California's coastline to spend the winter, usually between September and February. Results from the count so far show that the number of monarchs at 97 California overwintering sites has dropped from around 148,000 in 2017 to just over 20,400 this year. Counts for dozens of other sites are still being tabulated, but the outlook is troubling.

What's causing the dramatic drop-off is somewhat of a mystery. Experts believe the decline is spurred by a confluence of unfortunate factors, including late rainy-season storms across California last March, the effects of the state's yearslong drought and the seemingly relentless onslaught of wildfires that have burned acres upon acres of habitat and at times choked the air with toxic smoke. The Thomas Fire last year burned almost 300,000 acres, including areas important for monarch breeding and migration. More recently, the Woolsey Fire damaged at least four monarch butterfly overwintering sites in the Malibu area, according to Lara Drizd, a wildlife biologist with the U.S. Fish and Wildlife Service in Ventura.

1 of 148 comments (clear)

  1. Re: Maybe they are allergic to poop in streets by Anonymous Coward · · Score: 3, Insightful

    Actually a study in 2015 correlated the decline of milkweed due to use of pesticides across the states. Milkweed is the only food source for the caterpillars of these butterflies. By the time of the study the population has already dropped 90 percent in 20 years and the species was considered to be put on the list of endangered animals. What this has to do with trump, I have no idea.