The critically endangered monarch butterfly grew its presence in Mexico last year, giving a glimmer of hope to researchers who track the fluttering orange and black migrants despite a decades-long population collapse.
In one of the planet's most epic wildlife migrations, the slow-moving monarch butterflies travel south as far as 4500 kilometres from spots in Canada and the United States to hunker down for the winter in warmer Mexico, where millions cover entire trees that tourists flock to see.
Last winter, the pockets of Mexican forest where the intrepid insects end up each year saw 35 per cent more butterflies than in 2020, according to a study led by the local office of environmental organisation the World Wildlife Fund.
Biologists documented the presence of the species in 2.8 hectares last December in the two central Mexican states where they spend the winter, Michoacan and the State of Mexico, up from 2.1 hectares in December 2020.
In the mid-1990s, more than 18 hectares of Mexican forest was covered with monarch butterflies.
The race to help the species recover is also tied to the crucial role it plays in the health of interconnected species.
Monarch butterflies boost ecosystems as pollinators, with their migratory journey promoting a wide range of flowering plants as well as helping crops humans tend, WWF Mexico head Jorge Rickards said in a statement accompanying the study.
But dire challenges to the butterflies' future persist, including climate change, illegal logging, and the growing scarcity of the plants on which they lay their eggs.
Despite the recent uptick, the monarch butterflies "steady decline is worrisome", the WWF said.
The group recommends more scientific monitoring, sustainable tourism and forest management, as well as "alternative income-generating ventures" like mushroom production and tree nurseries to help restore the forest and boost local incomes.
Australian Associated Press
Sign up for our newsletter to stay up to date.