The Latest Monarch Butterfly Breeding Pattern Shows That Their Population May Be on the Rise

The monarch butterfly population has been fragile for many years now, but there is a sign of hope for these majestic insects. Last winter, researchers found that the Western Monarch butterfly population dropped from 300,000 approximately three years ago to just 1,914 in 2020, leading many conservationists to worry about extinction. However, there have been large sightings of Monarchs, particularly in the San Francisco Bay Area, due to their wintertime breeding patterns. Experts say that an increase in caterpillars also indicates that the Monarch populations are breeding across the state of California and are adapting to climate change.

"There's more to it than just counting overwintering butterflies," said David James, an associate professor in Washington State University's Department of Entomology. "It seems that Monarchs are evolving or adapting, likely to the changing climate, by changing their breeding patterns."

Monarchs are particularly prosperous in Australia, which has a similar climate to California. They play a significant role in ecology and are an important part of the food chain, which is why it's so important to conservationists that they are not only preserved, but can thrive through an ever-changing climate.

monarch butterflies on flowers
monarch butterflies on flowers

DebraLee Wiseberg / Getty Images

Related: Seven of the Best Places to See Butterflies in the United States

"The Monarch is like the cockroach of butterflies," James said. "It's very persistent and adaptable all around the world. The population decline is very worrying, but I remain optimistic that it will persist in the western US, although maybe at lower levels than before," says James.

There's even better news for butterflies across the pond. Farmers in the UK have single-handedly saved the Duke of Burgundy butterfly population. It was Britain's rarest butterfly ten years ago, but its population has grown by 25 percent. This is especially significant because its numbers had fallen by 46 percent in the 1990s. The Butterfly Conservationist launched an effort back in 2011 to help save the Duke of Burgundy. 1,000 volunteers—ranging from professional conservationists to concerned citizens—helped to restore the butterflies' natural habitat and have since seen success.

"We don't know if this adaptation will continue and how successful it will be," James said. "The western Monarch population is quite precarious right now. It's at a tipping point, and something is happening. We need to do more work to find out exactly what is happening."