The decline in monarchs has continued over the past year, with the area these butterflies occupy on their wintering grounds in Mexico declining by 22%.
• Also read: “A cry from the heart” to protect the monarchs
• Also read: Montreal is asking the federal government to offer better protections to monarchs
Year after year, monarchs living in eastern North America in both Canada and the United States travel about 4,500 km to reach the forests of Mexico.
A total of 11 colonies have been sighted this year, including six in the monarch butterfly biosphere reserve, reported the World Wildlife Fund, which, with help from the National Commission, is tracking the evolution of this insect’s population in protected natural areas in Mexico.
However, these colonies covered only 2.21 hectares of forest in December 2022, up from 2.84 hectares a year earlier, an area that decreased by 0.63 hectares (22%), the researchers evaluated in a study published on Tuesday.
Since it is impossible to count butterflies individually, scientists rely on the area occupied by the colonies formed by the butterflies to estimate their population.
In parallel, the Global Fund found that 58.7 hectares of forest have been lost in the protected area over the last year, mainly due to deforestation (28.7 hectares), fires (15.1 hectares) and illegal logging (13.9 hectares). . That area has tripled since last year, when 18.8 hectares of forest were lost on the reserve.
In addition to deforestation, monarchs are threatened by climate change, which will bring more severe weather and disrupt their migration. These pollinators also suffer from urbanization and biodiversity loss, as they desperately need to find milkweed along the way to feed and reproduce.