Monarchs reign in Mexico

The Mexican Environment Secretary, Rafael Pacchia, says that the number of monarch butterflies hibernating in his country will be three to four times greater this winter than it has been in recent years, writes Richard Collins

Actions taken by Mexico the US and Canada, it is claimed, have improved the butterfly’s prospects; at any rate, more of them are being recorded along the country’s northern border. Most will spend the winter at the Monarch Butterfly Biosphere Reserve in a mountainous forested area 100km north-west of Mexico City.

An increase in monarch numbers would be especially welcome; the population has been declining for 20 years. There were about one billion monarchs in Mexico during the 1990s but only 35 million were recorded in the annual census of 2009. Numbers had hit an all-time low. The 2015/16 winter census begins in December.