According to a recent report, the population of western monarch butterflies that migrate to California for the winter decreased by 30% last year, possibly as a result of unusually wet weather conditions.

According to the Xerces Society, a nonprofit organization dedicated to preserving invertebrates, volunteers recorded over 230,000 butterflies during their visits to California and Arizona during Thanksgiving, a decrease from the 330,000 recorded in 2022.

The number of orange and black bugs has recovered in the past few years, reaching hundreds of thousands after a sharp decline in 2020 to only 2,000 butterflies, which was a historic low. Despite the rebound, their population is still significantly lower than in the 1980s, when there were millions of monarchs.

Researchers have reported that butterflies in western regions are facing a critical decline, largely caused by the loss of their milkweed habitat due to urban development and the widespread application of pesticides and herbicides along their migration path.

The monarch butterfly’s annual 3,000-mile (4,828-kilometer) migration, which is timed to coincide with spring and the blooming of wildflowers, is being disrupted by climate change, posing a major threat to the species’ survival.

Emma Pelton, a conservation biologist for monarchs at the Xerces Society, stated that climate change is causing difficulties for many wildlife species, including monarchs. She also noted that the intense storms in California last winter, called atmospheric rivers, are connected to the changing climate.

The monarch butterflies from the western region migrate south to California during the winter months. They return to the same locations, often the same trees, where they gather together to stay warm. Along the way, they reproduce several times before reaching California by early November. As temperatures rise in March, they begin to disperse eastward from California.

In the east, a group of monarch butterflies migrates from southern Canada and the northeastern United States to central Mexico, while on the western side of the Rocky Mountains, the decline in monarch population has been greater than in the east, with scientists estimating a decrease of approximately 80% since the mid-1990s.

Source: wral.com