Butterfly population gets ‘reprieve’
U.S., Mexico surpass Canada in efforts to restore monarch habitat
One of nature’s greatest migrations may be returning to health after a stunning growth in the number of monarch butterflies that fluttered across North America last year.
But if populations of the striking black-and-orange aviators are starting to recover, it’s no thanks to Canada, said Carolyn Callaghan of the Canadian Wildlife Federation.
Canadian wildlife officials dispute that. They say the species is considered a priority and $14 million has been spent since 2012 on the butterflies.
Every year, the main population of monarchs numbering in the tens of millions migrates from Canada and the United States to overwinter in Mexico.
In recent years, the number of monarchs making the flight plummeted by about 90 per cent from historic numbers, Callaghan said.
Scientists estimate monarch numbers by measuring a tiny patch of central Mexican forest where they congregate. There can be anywhere from 10 mil- lion to 50 million monarchs per hectare. As recently as 1993, the butterflies took up 6.2 hectares. Last year, the size of forest where scientists could find them was down to 2.5 hectares.
But a newly released survey for 2018 found monarchs on more than six hectares of forest, which would suggest population numbers were up 144 per cent over 2017. One year’s increase is not necessarily a trend, but it’s good news.
“It’s a reprieve from a dire situation,” said Callaghan.
Mexico has cracked down on illegal logging that destroyed monarch habitat and is working to create ecotourism opportunities as a replacement. The U.S. has engaged in extensive re-plantings of the weeds and wild flowers monarchs need for nectar and egg-laying.
Southern Canada, especially Ontario and Quebec, contains important monarch breeding grounds. About one-third of the butterflies that show up in Mexico have been found to have originated in Canada or the northern states. The Americans and the Mexicans have far surpassed Canadian efforts to restore habitat, Callaghan said. That’s despite an agreement signed in 2016 between the leaders of the three countries to address habitat loss across breeding and migrating habitat.
“We have a role to play,” Callaghan said. “We have yet to do this.”
The butterflies are considered endangered but are not yet protected under the Species at Risk Act.