The government commission for natural reserves said the butterfly population covered 2.84 hectares (7 acres) this year, up from 2.1 hectares (5.2 acres) last year.
The annual butterfly count does not count the individual numbers of butterflies, but rather the number of acres they occupy when they freeze together on tree branches.
Each year the kings return to the United States and Canada on an annual migration that faces the loss of the weeds they feed north of the border and the threat of deforestation in Mexico.
Gloria Tavera, regional director of the Mexico Commission for National Protected Areas, said logging on butterfly winter land has increased by about 4.5% this year to 13.9 hectares (34 acres).
However, less trees have been destroyed due to fire, drought or tree diseases and pests. So the overall tree loss in the 2021-22 season was 18.8 hectares (46 acres), which decreased from 20.2 hectares (50 acres) in the 2020-21 season.
Butterflies traditionally come to the mountain peaks and fir forests west of Mexico City in late October and early November. They usually move to the United States and Canada in March.
Tavera, however, said last year was unusual, as the kings began to leave in February; This allows them to exit in April and May just before the drought and heat hit north of the border.
“They are beginning to adapt to extreme climatic conditions,” Tavera said
Surprisingly, this year, butterflies have been stuck in Mexico for longer than usual. “It simply came to our notice then. We still had butterflies in April, ”said Tavera. Whether that strategy works for them remains to be seen in next year’s statistics.
Workers and students in the United States and Canada have been urged to plant milkweed, clear farms and pastures, and compensate for plant damage caused by the use of pesticides, a strategy that has been reversed in Mexico.
Tavera urged Mexicans not to plant milkweed in Mexico, saying it could hinder migration by encouraging kings to stick around instead of moving north. He urged the people not to reproduce kings in captivity – they are sometimes released at weddings or other celebrations – saying that it could spread the disease among insects.
Despite the increase this year, “it continues to be a risky immigration phenomenon,” said George Richards of the WWF Environmental Group.
One highlight is that more than 160,000 tourists visited butterfly stocks in Mexico in 2021, an increase of 132% over the number visited during the coronavirus epidemic in 2020.
Local collective farm groups who own most of the conserved forests rely on tourism for income and to discourage logging.
Annual butterflies are counted every December. There are millions of people who do not count the individual numbers of butterflies in the survey, but rather how many acres they occupy when they freeze together on a tree branch.
Droughts, severe weather and habitat loss – especially in milkweeds where kings lay eggs – as well as the use of pesticides and herbicides and climate change, all pose a threat to species migration. Illegal logging and loss of tree cover due to diseases, droughts and storms have also hit the reserves.