Although they are not officially listed as endangered, monarch butterflies (Danaus plexippus) are thought to be significantly declining
Over the past few decades, monarch numbers have been falling. The eastern migratory population, which breeds in the United States and Canada and spends the winter in Mexico,
Although not globally designated as endangered or critically endangered, monarchs are regarded as a species of conservation concern in a number of places
Deforestation, urbanization, and agricultural growth are causing the loss of both breeding and overwintering habitats. The only plant that serves as a host for monarch larvae, milkweed,
Monarch migration patterns, breeding cycles, and resource availability are all impacted by climatic changes. Changes in temperature and severe weather
Milkweed populations and other plants that supply nectar for adult monarch butterflies have suffered as a result of the extensive use of herbicides and pesticides in agriculture.
Illegal logging in the oyamel fir forests of Mexico, where monarchs overwinter, has decreased the vital overwintering habitat, affecting the monarchs' ability to survive the winter.