When millions of monarch butterflies take to the sky and fly thousands of kilometres from the United States and southern Canada to Mexico, the view is breathtaking. But over the last few decades, their numbers have plummeted, and last year hit an all-time low.
Illegal logging in Mexican forests, where the monarchs hibernate during winter, has traditionally been to blame. But large-scale logging by companies appears to have been halted. And now small-scale logging by local people for firewood and timber — a “growing concern in 2013” — has also stopped, according to a study published last month (27 October) in Biological Conservation.
This is partly due to “decade-long financial support from Mexican and international philanthropists and businesses to create local alternative income generation and employment”, it says. Schemes such as community tree nurseries, the growing ecotourism sector and community surveillance of illegal logging have generated new sources of income for local people.
Twenty years ago, around a billion monarchs arrived each year in Mexico. Last year, just 35 million arrived, the lowest number since monitoring began 20 years ago, says Omar Vidal, director of WWF-Mexico, a national office of conservation organisation the World Wide Fund for Nature, and a coauthor of the study.
“Our decade-long research shows that action to stop illegal logging in the monarch overwintering grounds are working thanks to efforts from local communities, authorities, civil society organisations and the private sector,” he adds.
Each year, the butterflies migrate up to 4,500 kilometres from their North American breeding grounds east of the Rocky Mountains to spend the winter — typically from October to March — hibernating in the fir and pine forests of central Mexico.
Until just a few years ago, large-scale illegal logging was devastating the Monarch Butterfly Biosphere Reserve, a 56,000 hectare area of forest established by the Mexican government in 1980. But this has now largely stopped. Between 2001 and 2012, Vidal and his WWF-Mexico colleague Eduardo Rendón-Salinas monitored the amount of forest damaged by illegal logging.
In a study on this research published in Conservation Biology last year, they found that 731 hectares of the reserve were affected from 2005 to 2007. In 2012, thanks to law enforcement and surveillance efforts, none of the reserve was damaged, they reported.
Continue reading at ENN affiliate, SciDev.Net.
Monarch butterfly image via Shutterstock.