Last Tuesday, researchers announced the number of western monarch butterflies wintering along California’s coasts has dropped to a record low. They say this moves these colorful insects closer to their extinction.
Xerces Society, a nonprofit organization dedicated to conserving invertebrates, recorded less than 2,000 butterflies when they finished their annual winter count. This is a staggering drop from the tens of thousands they counted in the previous years. The numbers are even more unimaginable when millions of the monarch butterflies swarmed Northern California’s Marin County all the way to San Diego in Southern County in the 1980s.
Last winter, the Xerces Society counted about 29,000 butterflies. The year before they tallied an all time low of 27,000 butterflies. This year’s count of less than 2,000 was devastating.
Numerous wintering sites such as Pismo State Beach Monarch Butterfly Grove and Natural Bridges State Park only housed a few hundred butterflies. Other volunteers at other wintering sites didn’t see a single butterfly.
Sarina Jepsen, director of endangered species at Xerces Society, said:
“These sites normally host thousands of butterflies, and their absence this year was heartbreaking for volunteers and visitors flocking to these locales hoping to catch a glimpse of the awe-inspiring clusters of monarch butterflies.”
Migration Patterns of Monarch Butterflies
Each year, the western monarch butterflies follow a certain pattern of migration. From the Pacific Northwest, they head south down to California, where they cluster together to keep warm. They usually arrive in California in November and start to deviate when warmer weather hits in March.
There is another population of monarch butterflies that migrate on the eastern side of the Rocky Mountains. They travel from southern Canada and northeastern United States all the way to central Mexico for the winter. Since the mid-1990s scientists estimated that the monarch butterfly population has dropped about 80%. Unfortunately, the decline in numbers has been way worse in the western United States.
Scientists say that monarch butterfly populations are at an all time low due to the destruction of their habitats. As housing projects expand and the use of herbicides and pesticides increase, their milkweed habitats along their migratory routes are being demolished.
Climate change and farming have also played big roles in disrupting the migration of monarch butterflies, according to researchers. The wildfires that plagued western U.S. have also caused disarray for the breeding and migration of the butterflies.
Monarch butterflies do not have state or federal legal protection for the preservation of their habitats. Last December, federal officials made them a “candidate” for threatened or endangered species. Unfortunately, action won’t be taken for several years, as there are numerous other species waiting for that designation.
Xerces Society has said that it will work “to implement science-based conservation actions urgently needed to help the iconic and beloved western monarch butterfly migration,” partnering with a wide variety of organizations.
As a way to help, Xerces Society has suggested that people plant early-blooming flowers and milkweed to help spur the migration of these colorful butterflies.