4 ms·

Monarch population health is a little easier to monitor, because they do large migrations to a few main locations, which can be evaluated, and (hopefully) prote

• cableshaft 5y ago
  Being able to monitor hasn't really helped us protect them at all: "In 2017 the annual March count of monarchs "overwintering" in Mexico's mountain forests — where 99 percent of the world's monarchs migrate for the winter — showed that numbers had fallen by 27 percent from the previous year's count and by more than 80 percent from the mid-1990s. That drastic decline was attributed in part to more extreme winter storms that killed millions of monarchs the previous March. Monarchs need a very large population size in order to be resilient to threats from severe weather events, pesticides and climate change. In 2020 the yearly count of overwintering monarchs showed an even more dramatic decrease of 53% from the previous year’s count. The numbers are now well below the threshold at which government scientists predict the migration could collapse. The western monarch population, which overwinters in California, is in even greater peril. Numbering some 1.2 million in the 1990s, it declined to fewer than 2,000 butterflies in the 2020 count. This is way below the extinction threshold estimated by scientists and has to be turned around soon if the species is to be saved. " https://www.biologicaldiversity.org/species/invertebrates/monarch_butterfly/ https://www.biologicaldiversity.org/species/invertebrates/mo...