FREDERICTON — Many butterflies, bees and moths are fluttering into oblivion. A new report co-authored by a Canadian researcher warns that more than one-fifth of pollinator species it studied in North America are at risk of extinction.
Out of 759 pollinators — animals critical for food production and healthy ecosystems — studied in Canada, more than 10 per cent were at some level of risk of extinction, says the study published this week in the journal Proceedings of the National Academy of Sciences, or PNAS. And of 1,579 pollinators assessed in the United States, 22.5 per cent were found to be at some level of risk.
The study is the most comprehensive look at North American pollinators and their conservation status to date, John Klymko, scientist at Atlantic Canada Conservation Data Centre in Sackville, N.B., and one of the co-authors, said in a recent interview.
Commonly known pollinators, which transfer pollen from one flower to another, are bees, butterflies and moths, Klymko said. But they also include vertebrates like hummingbirds and bats. “Many plants are reliant on pollinators in order to reproduce,” he said.
The study noted that pollinators provide more than $15 billion worth of food each year in North America.
Among the insect pollinators, extinction risks were highest with bees. Out of 472 species of bees studied in Canada and the U.S., 34.7 per cent were at risk of extinction. The study said that 10 bee, 11 butterfly, and two moth species were classified as critically imperilled.
Flower flies and beetles are relatively secure from extinction, but all three pollinating bat species are at risk of extinction. The 17 hummingbird species studied have seen a population decline but their numbers are high enough that they don’t qualify for an at-risk status.
“Certain species (pollinate) only a handful of plants. And so if you start to lose that diversity of pollinators, there are going to be plant species that are affected.”
Klymko studied the extinction risk for flower flies for the paper.
“They’re an attractive group of flies. A lot of them are bee or wasp mimics,” he said, describing the insects.
“They hang out on flowers, so it benefits them to look like an insect that can sting you. They trick predators into thinking that they would be stung. So they are a lot of pretty spectacular looking flies. They’re a diverse, diverse group.”
The risk for pollinators is lower, on average, in Canada because many species are distributed over larger areas than they are in the United States. Although there are some Canadian species that are quite restricted in range, and that puts them at an elevated risk level, he added.
Some pollinator species have large ranges such as the boreal forest, which extends from Atlantic Canada all the way to the Yukon, he said.
But he pointed out that some Canadian species are reliant on rare habitats in places such as southern Ontario, the prairies, and in British Columbia’s Okanagan Valley, where there is fairly high pollinator diversity.
“But there is also a fairly heavy human footprint (in those regions), and continued pressure on the landscape from humans,” he said, warning against complacency.
Habitat loss, pesticide exposure, climate change, and disease can all adversely affect pollinators, the study said. Klymko said climate change can disturb the routine of pollinators, causing them to emerge from hibernation “before the flowers they rely on are blooming.”
He said pesticides, while primarily used in agricultural areas, can drift to natural ecosystems, killing insects.
Habitat loss such as urban development is a significant driver of species loss, he added. What surprised Klymko the most about the study was the overall percentage of species at risk, he said.
“More than one-fifth of the species that were assessed were at risk,” he said. “That’s a sobering statistic.”
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