An annual survey of monarch butterflies hibernating in Mexico found that the population was 144 percent higher than it was in 2018. The results, said the World Wildlife Fund (WWF) on Wednesday, offered “a testament to the power of conservation,” though the group added, “Monarch populations remain far smaller than they were 20 years ago.”
Monarch habitat covered 14.94 acres this year compared to 6.12 acres last winter. Researchers from WWF-Mexico and its partners found eight butterfly colonies in the reserve set aside by Mexico for the wintering monarchs and six colonies outside it. The largest colony covered more than six acres of forest.
The butterflies travel up to 2,500 miles from Canada and the United States to spend the winter in Mexico. Environmentalists say climate change, forest degradation, and the loss of grasslands to farmland have affected monarch populations.
The Guardian said that this year’s wintering area was the largest since 2007. Habitat reached its lowest point, just 1.66 acres, in 2014. “Scientists said the approximately 15 acres of coverage should be seen as a minimum for the viability of the migrating monarchs in the future,” it said. The WWF has urged homeowners to plant gardens with flowers to feed the butterflies during their migration and to grow milkweed, the only plant on which monarchs lay their eggs.