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As September arrives, our series on the Science of Summer is still in full swing. Today Tom Spears finds good news that no one expected for a brilliant butterfly that was once found all over this region in late summer.
Monarch butterflies, the flashy insects that have been close to extinction for years, are suddenly flapping their orange-and-black wings all over our region in a population boom that has stunned biologists.
“In the last several years you look around and you (didn’t) see any of them. You could spend your entire summer hunting and see four. You can spend 10 minutes right now and see 40. It’s great,” said Jeremy Kerr, who studies butterflies at the University of Ottawa.
“They seem to be having a completely stellar year in eastern North America and it’s looking like we could get some really welcome news in terms of beginning a population recovery this year.
“Monarchs have been having a pretty tough time for years and years,” he said. “We’ve been looking at a general and strong downward trend in their population.
“It’s way to early to say, oh, monarchs are fine. They haven’t gotten through one year yet without running into some major obstacle… that causes their populations to plummet again.” One winter storm in the mountains of Mexico can kills tens of millions.
“But cruising around southern Ontario I’ve been through Prince Edward County and the Niagara Region and around Point Pelee. I’ve never seen so many monarchs in my life.” (Kerr is 46 and grew up in Windsor.)
“This is short-term but good news.”
The reason for this baby boom is still unknown. It’s unlikely that changes in pesticide use or a sudden increase in milkweed (where the butterfly lays its eggs) are the reason, he said. “What has not happened is that suddenly everybody stopped using pesticide in North America.”
He believes it is more likely that the monarch has been lucky with the weather, avoiding storms and also avoid hot, dry weather that reduce the supply of wildflowers and nectar.
As well, the monarch migrates from Mexico to Canada each spring and summer, which means it has to have a string of luck that carries it over a long distance without a break.
“This is a reminder to us that weird weather extremes, which are linkable in a general sense to climate change, are atrocious mortality drivers for populations like monarchs.”
The monarch is considered endangered in Canada. As well, its 4,000-kilometre migration is officially a “threatened process” as assessed by the International Union for the Conservation of Nature (IUCN).
Monarch Watch, a blog devoted to monarch conservation, reported in July that numbers should be good through the summer and there should be strong numbers in the fall migration.
Monarchs were once common across southern Canada. Their decline has been blamed on a variety of factors, including climate change and the expansion of the U.S. corn belt. As farmers spray weedkillers on thousands of square kilometres of farmland, it kills the milkweeds on which monarchs depend.
The butterfly goes through several generations each year. One insect flies all the way from Canada to Mexico and stores fat from flower nectar to sustain itself through the winter, but it takes about three generations to make the trip north in spring.
tspears@postmedia.com
twitter.com/TomSpears1
查看原文...
Monarch butterflies, the flashy insects that have been close to extinction for years, are suddenly flapping their orange-and-black wings all over our region in a population boom that has stunned biologists.
“In the last several years you look around and you (didn’t) see any of them. You could spend your entire summer hunting and see four. You can spend 10 minutes right now and see 40. It’s great,” said Jeremy Kerr, who studies butterflies at the University of Ottawa.
“They seem to be having a completely stellar year in eastern North America and it’s looking like we could get some really welcome news in terms of beginning a population recovery this year.
“Monarchs have been having a pretty tough time for years and years,” he said. “We’ve been looking at a general and strong downward trend in their population.
“It’s way to early to say, oh, monarchs are fine. They haven’t gotten through one year yet without running into some major obstacle… that causes their populations to plummet again.” One winter storm in the mountains of Mexico can kills tens of millions.
“But cruising around southern Ontario I’ve been through Prince Edward County and the Niagara Region and around Point Pelee. I’ve never seen so many monarchs in my life.” (Kerr is 46 and grew up in Windsor.)
“This is short-term but good news.”
The reason for this baby boom is still unknown. It’s unlikely that changes in pesticide use or a sudden increase in milkweed (where the butterfly lays its eggs) are the reason, he said. “What has not happened is that suddenly everybody stopped using pesticide in North America.”
He believes it is more likely that the monarch has been lucky with the weather, avoiding storms and also avoid hot, dry weather that reduce the supply of wildflowers and nectar.
As well, the monarch migrates from Mexico to Canada each spring and summer, which means it has to have a string of luck that carries it over a long distance without a break.
“This is a reminder to us that weird weather extremes, which are linkable in a general sense to climate change, are atrocious mortality drivers for populations like monarchs.”
The monarch is considered endangered in Canada. As well, its 4,000-kilometre migration is officially a “threatened process” as assessed by the International Union for the Conservation of Nature (IUCN).
Monarch Watch, a blog devoted to monarch conservation, reported in July that numbers should be good through the summer and there should be strong numbers in the fall migration.
Monarchs were once common across southern Canada. Their decline has been blamed on a variety of factors, including climate change and the expansion of the U.S. corn belt. As farmers spray weedkillers on thousands of square kilometres of farmland, it kills the milkweeds on which monarchs depend.
The butterfly goes through several generations each year. One insect flies all the way from Canada to Mexico and stores fat from flower nectar to sustain itself through the winter, but it takes about three generations to make the trip north in spring.
tspears@postmedia.com
twitter.com/TomSpears1
查看原文...
