Tag: Invasive species

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Cottage Life

Why the spongy moth (LDD) outbreak has vanished in Québec

Photo by Jay Ondreicka/Shutterstock

Last year, forests across southern Québec and Ontario and much of New England turned eerily leafless. The air hummed with the sound of munching mandibles and tree trunks were covered with a writhing carpet of caterpillars, while showers of caterpillar poop fell softly on the heads of unsuspecting hikers and campers.

The population of the European spongy moth, which had been gradually increasing since 2019, reached a dramatic peak in 2021 and completely vanished this year.

FAQ: Spongy moth (formerly LDD moth) caterpillars 

In 2020, the hungry caterpillar damaged 583,157 hectares of forests in Ontario and this number is bound to go up when the 2021 numbers are revealed.

Insect outbreaks are one of the most important natural disturbances in Canadian forests. As a biologist who has been working on plant-insect interactions for over 20 years, I see that the frequency, intensity and range of insect outbreaks keeps changing. To protect trees in our forests and cities, we need tree diversity.

Insect Outbreaks

An insect outbreak can be frightening. In deserts around the world, vast swarms of locusts can blot out the sun for hours as they fly overhead. In the Rocky Mountains, hillsides are covered with dead trees, killed by the inner-bark-eating mountain pine beetle.

However, insect outbreaks are not a new phenomenon. Chinese historical records document locust outbreaks for almost 2,000 years, while paleo-ecological studies show that Québec’s boreal forests have witnessed spruce budworm outbreaks for at least 8,000 years.

Such insect outbreaks are part of how temperate and boreal forests—as well as semi-arid grasslands and deserts—function. Insect outbreaks stimulate nutrient cycling, accelerate forest succession and can renew forests.

Female insects can produce hundreds of offspring and for the population to remain stable, only two of these need to survive. A small increase in survival, due to factors like favorable weather conditions, can lead to a population explosion and an outbreak.

In the case of the mountain pine beetle and the desert locust, warming temperatures, increased cyclone activity and other such effects of climate change are bringing these favorable conditions more frequently to new areas, thus dramatically increasing the extent of outbreaks.

However, these outbreaks always come to an end because of what ecologists call lagged-density dependent population dynamics. Here, density-dependent means that the insects’ mortality rate depends on the density of its population. As the population increases, mortality also increases and survival rate decreases. Meanwhile, lagged means there is a delay in this process—the insect mortality increases more slowly than population growth, causing an outbreak.

The outbreak crashes when the insect mortality eventually catches up with its population size. This usually happens due to a combination of factors including low food supply and increase in predators, parasitoids— insects that lay their eggs inside other insects—and diseases.

Where did the spongy moth go?

Students in my laboratory have been rearing spongy moth caterpillars for the past three years and have found that the mortality of these caterpillars gradually increased as the population grew.

In 2019, one student, Pamela Yataco Marquez reared over 300 caterpillars and observed an 80 per cent survival rate. However, this year, despite an extensive search, Marie-Eve Jarry, Geovana Demarchi and Victoria Yip were able to find and rear only 97 caterpillars and only six survived to adult.

A freshly emerged lab-reared moth.
This freshly emerged lab-reared female spongy moth is one of the few survivors of 2022.
(Victoria Yip), Author provided

Several mortality agents including a virus Lymantria dispar multiple nucleopolyhedrovirus, the fungal disease Entomophaga maimaiga and two tiny parasitoid wasps called Cotesia melanoscela and Ooencyrtus kuvanae finally caught up with the insect population.

When parasitoids eggs—laid inside either the eggs or the bodies of other insects—hatch, they devour their host from the inside and eventually emerge from the dead host, ready to start the life-cycle anew.

They are more like predators than parasites because they kill their host, and are efficient biocontrol agents that decrease pest insect populations.

How to protect your trees from moth outbreaks

Creeping across borders

While the spongy moth is native to Europe, it has been in eastern North America since the 1860s and is part of our fauna now.

It has not reached the western part of the continent yet and the best way to stop this is to inspect outdoor gear for caterpillars or egg masses before travelling and not to move firewood.

The Asian spongy moth population has not spread in North America yet, and entomologists are working hard to keep it out.

A moth caterpillar on a partially eaten leaf.
The current range of the spongy moth distribution in North America extends up to southern Canada.
(Geovana Demarchi), Author provided

In the past 150 years, many of the European spongy moth’s natural enemies, including the fungal disease mentioned above and several parasitoids, have also been introduced, either inadvertently or deliberately. Our findings show that these natural enemies are well established in our region and have been effective in collapsing the outbreak.

The current range of the spongy moth distribution in North America extends up to southern Canada. Here, the eggs that spend the winter on tree trunks suffer high mortality due to cold, knocking down the survival rate irrespective of population size.

Forest managers in Québec and Ontario are on the alert for increases in spongy moth outbreaks—including both more severe and longer duration outbreaks similar to those seen in the U.S.—and a possible northward shift of the distribution range.

Diverse forests

While a tree that is leafless in July may appear dead, many trees can survive a few years of defoliation, drawing on stored reserves to flush out new leaves.

The spongy moth outbreak in the Montréal area in the late 1970s slowed tree growth, but did not cause the widespread death of forest trees. However, tree mortality does occur further south in the U.S. and depends on the diversity of trees in the forest area. The death of tree species preferred by the caterpillar is lower in diverse forests that mix in less-vulnerable species.

Diverse forests are more resilient under various stresses than more homogeneous ones. We need to create and preserve such diverse forests to help prepare for new types of insect outbreaks in our changing world.The Conversation

Emma Despland, Professor, Biology Department, Concordia University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Cottage Life

Jellyfish found in Sudbury-area lake

Photo by Rostislav Stefanek/ Shutterstock

This past summer, scuba divers in Sudbury discovered an unlikely form of aquatic life in the city’s Ramsey Lake. In late August, diving instructor Jason Fox captured a video of jellyfish, marking the first time the invasive species has been documented in Ontario outside of the Great Lakes. In a video, translucent, dime-sized craspedacusta sowerbii jellyfish pulsate with tentacles suspended in the water column. 

“It’s a crazy story and it’s received a lot of attention,” says John Gunn, Canada Research Chair in biology at Sudbury’s Laurentian University and the director of the Vale Living With Lakes Centre. “Jellyfish are usually thought of as marine species. People find it remarkable to learn that we have them here in freshwater.”

Fox told CBC that he “basically stopped counting” jellyfish after three weekend dives in Ramsey Lake, estimating to have seen 50 or more on September 11. His photos and video is the first evidence of jellyfish in Ramsey Lake, but Gunn suspects they’ve been around for perhaps a decade or more. Craspedacusta sowerbii, which is native to China’s Yangtze River, arrived in North America in the 1930s. “It likely came in ships’ ballast water or as part of the aquarium plants trade,” Gunn explains. “It is yet another example of the many species that have joined North American flora and fauna due to human movements.”

How to avoid spreading invasive species in lakes

The scientific literature suggests the freshwater jellyfish found in Ramsey Lake are innocuous. They eat microscopic phytoplankton in the water column, haven’t been linked to any adverse ecological effects, and swimmers don’t need to worry about the toxic stingers of some marine jellyfish. “They’re elegant and mesmerizing,” adds Gunn. “Divers and swimmers will really enjoy watching them in the water.”

Still, Gunn says the discovery is another cautionary tale of invasive species. “They aren’t like silver carp,” he notes, referencing the oversized exotic fish that have taken over waterways in the southern United States. Gunn hopes jellyfish in Ramsey Lake serve as a reminder of the ways humans have transported plants and animals all around the globe. “When you look at the lake,” he says, “realize that you’re glimpsing into a whole sea of biota that’s made its way here from elsewhere.

“We don’t have any specific concerns with jellyfish, but we do have to worry about others,” Gunn adds. “Stuff gets moved around in bait buckets and on motorboats. Humans are the vectors of countless nuisance species. We have to be extra cautious.”

 

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Cottage Life

Hemlock trees have a new invasive enemy

Courtesy Ontario Ministry of Natural Resources and Forestry

Ontario’s latest forest invader looks like “invasive fluff,” says Canadian Forest Service research scientist Chris MacQuarrie. And really, how scary is that? 

Plenty scary for anyone who values the province’s dense stands of hemlock. 

Despite its fuzzy appearance, the aphid-like Hemlock Woolly Adelgid (HWA) literally sucks the life from its victims—a tiny vampire that “quickly overwhelms the tree’s ability to defend itself,” MacQuarrie says. “It’s another invasive that kills its hosts really quickly and has the potential to change ecosystems.”

The HWA landed in Virginia on Japanese nursery stock in 1951. Since then it has been spreading through the eastern States towards the Great Lakes, riding on infected wood, catching a lift on the wind, or even cruising on migrating birds. In 2017 the HWA was discovered in southwestern Nova Scotia, where MacQuarrie says it’s causing “significant mortality.” 

Nature scrapbook: meet the hemlock tree

Now it’s Ontario’s turn. This past summer researchers found the bugs in hemlocks near Grafton. Infested trees were found within about 40 acres of a mixed woodlot, with many displaying extensive damage, though an exact number of trees killed by the pest is not available. The Canadian Food Inspection Agency (CFIA) has delivered a Notice of Prohibition of Movement to the property owner, which restricts them from moving any wood or wood material from their property. The CFIA has provided information to them on the restrictions of movement of hemlock that could contribute to the spread of this pest.

It’s not the first sighting of HWA in Ontario—during the past decade, isolated infestations were wiped out in Toronto and the Niagara Gorge, and another Niagara outbreak is contained by farm fields and development. But the Grafton bugs are close to Ontario’s hemlock heartland, stretching from the Ottawa Valley through Algonquin Provincial Park to the Kawartha Lakes and Muskoka District. If the bugs spread, the ecological impact could be severe: hemlock provide crucial habitat for everything from moose and deer to brook trout and Blackburnian warblers. The trees’ towering foliage also cools riparian areas and buffers shorelines and ravines from erosion. 

Battling invasives with slingshots

So while researchers look for ways to control the bug, MacQuarrie’s asking cottagers and landowners to track new outbreaks by scouting for telltale woolly fluff at the base of the hemlock needles, and reporting sightings to the CFIA or the Ontario Ministry of Natural Resources and Forestry. 

The HWA secretes this waxy, fuzzy coating to protect and insulate itself and its eggs. Infestations usually start near the tops of the tree and work downward. “Be observant if you see declining hemlock,” MacQuarrie says. “Usually once the insect gets down to eye level it has already been there for a while.” 

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Cottage Life

Good enough to eat? This state is hoping to revamp Asian carp’s image

Photo by Mironov Vladimir/Shutterstock

Asian carp are getting a new name—but only in the state of Illinois. Last month, Illinois’ Department of Natural Resources announced that it was changing the name Asian carp to copi (a play on copious for their abundant numbers).

The rebrand is an attempt to dismiss long-held misconceptions about Asian carp and to reintroduce the fish as a delicious meal option. “It’s a tasty fish that’s easy to work with in the kitchen and it plates beautifully. Every time we’ve offered samples during the Illinois State Fair, people have walked away floored by how delicious it is,” said Illinois Department of Natural Resources director Colleen Callahan, in a statement.

Asian carp are often mixed up with common carp, a bottom feeder with a mucky taste. Asian carp are top-feeder, white fish that are high in omega-3 and omega-6 fatty acids, rich with protein, and low in mercury.

large common carp being held by angler
The common carp is often confused with the family of Asian carp. They are bottom feeders and unlike silver carp have barbels. Photo by malgosia janicka/Shutterstock

“Copi is more savoury than tilapia, cleaner tasting than catfish, and firmer than cod,” said chef Brian Jupiter of Chicago’s Ina Mae Tavern, in a statement. “It’s the perfect canvas for creativity—pan-fried, steamed, broiled, baked, roasted, or grilled. Copi can be ground for burgers, fish cakes, dumplings, and tacos.”

Since the name change, 21 Illinois chefs and retailers have committed to adding Asian carp to their menus. Copi has yet to be made official, but Illinois plans to apply to formally change the name with the U.S. Food and Drug Administration by the end of the year.

By revamping Asian carp as a consumer-friendly option, Illinois is hoping to reduce the species’ population within the state. Asian carp are an invasive species brought to North America from Asia in the 1960s and 70s. The fish have taken over U.S. waterways, decimating native species. Asian carp have replaced all native species in certain sections of the Mississippi River and make up more than 50 per cent of the fish, by weight, in sections of the Illinois River.

Asian carp is actually a catchall term for four types of fish: the silver carp, bighead carp, grass carp, and black carp. These four species reproduce rapidly, eat up to 20 per cent of their body weight in plankton each day, and can weigh up to 40 kilograms, reaching a metre in length.

Bighead carp on a dock

Photo courtesy Asian Carp Canada

Bighead carp

Black carp on white background

Photo courtesy of Asian Carp Canada

Black carp

Grass carp

Photo by Edvard Ellric/Shutterstock

Grass carp

Silver carp on white background

Photo by photomaster/Shutterstock

Silver carp

They have yet to become established in Ontario waters thanks to both the U.S. and Canadian governments implementing programs to keep the carp out of the Great Lakes. If they were to become established in the Great Lakes, the carp would pose a threat to the $7 billion-a-year commercial fishing industry and $16 billion-a-year tourism industry.

But not everyone is supportive of the Illinois name change. In an email, the Ontario Federation of Anglers and Hunters (OFAH) said that while increasing the fishes’ popularity could contribute to reducing the population, there is concern that creating a viable and desirable market for an invasive species will encourage individuals to introduce this species elsewhere. “Something we obviously do not want to happen.”

OFAH said it couldn’t speculate on whether the Ontario government would ever change the Asian carp name to copi, but, “if a name change [did] occur in Ontario and Canada…it would be guided by science as well as a desire to prevent any possible introduction of these species into our waters.”

Under Canada’s Federal Fisheries Act and Ontario’s Invasive Species Act, live possession of Asian carps is prohibited, unless dead and gutted.

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Cottage Life

The battle against invasive sea lamprey in the Great Lakes rages on

Photo by T. Lawrence/Great Lakes Fishery Commission

For the past two years, COVID-19 impeded conservation operations in the Great Lakes. Now, the Great Lakes Fishery Commission is ramping up efforts to contain invasive sea lampreys that threaten the wellness of the ecosystem.

Sea lamprey management is a fickle but important part of Great Lakes conservation. Since the 1950s, Canada and the U. S. have been working in tandem to keep the invasive species in check and preserve the $7 billion Great Lakes fishing industry. However, in 2020 and 2021, pandemic restrictions prevented conservation workers from undertaking their usual ecosystem management efforts in the Great Lakes.

In the past, when control was eased, lamprey populations grew relatively quickly. However, Marc Gaden of the Great Lakes Fishery Commission, which is in charge of sea lamprey management, says the organization is hopeful that renewed containment efforts will keep the population in check this time around. “We’re cautiously optimistic that we can weather this,” says Gaden.

What’s happening right now?

The pandemic limited the Commission’s capacity to work in the field and manage lamprey populations. The Fishery Commission’s lamprey management operations were only able to run at roughly 25 per cent capacity in 2020, and 75 per cent in 2021. “COVID set us back a bit, the past two seasons have been highly curtailed because the crews couldn’t get out there,” Gaden explains.

The lampreys that are spawning now, are survivors from the 2020 season. This means the Commission won’t know until the fall, once they’ve fully analyzed all the available data, how significantly the population has changed.

Still, Gaden is cautiously optimistic about the situation. The Commission had been aggressively controlling the sea lamprey population in the decade leading up to COVID-19, which happened to set them up well for the pandemic, says Gaden. “We went into COVID as well-positioned as you can be for a disruption of that size.”

Both the Canadian and American governments have provided the Great Lakes Fishery Commission with additional resources, allowing them to step up the battle against the sea lampreys, says Gaden. Now, the Commission is working at maximum capacity to apply the lampricide treatments. “We’re well-positioned from a resource position to really take this battle to the lamprey and to continue to suppress the populations to the target level we’ve set.”

What are sea lampreys?

Sea lampreys have been a thorn in the side of Great Lakes conservationists for a century. They’re ancient blood-sucking creatures with eel-like bodies and rows of concentric teeth. While the creatures are healthy contributors to their natural environment off the Atlantic coast, they’re devastating to the fish of the Great Lakes. 

“From a scientific point of view, even though sea lamprey are a huge pest in the Great Lakes, lampreys as a whole are evolutionarily pretty fascinating,” says Margaret Docker, a professor at the University of Manitoba who studies lamprey biology and freshwater fish conservation. Sea lampreys began to evolve half a billion years ago. The ancient sea creatures are often mistakenly referred to as eels thanks to their long and skinny bodies, but they’re actually considered jawless fish. “Almost all the lineages of jawless fish went extinct, and lampreys are one of the few survivors from that time, 400 million years ago,” says Docker.

Parasitic sea lampreys use their jawless but teeth-lined mouths to suction onto a host fish. Then, they use their tongue—which also has its own set of teeth—to chisel away at the flesh of their prey to suck up its blood. For those who are now scared to dip their toes into the Great Lakes, have no fear, sea lampreys only go after cold-blooded prey.

Docker says the larger fish of the Atlantic are able to handle the sea lamprey’s bite, which makes them little more than a nuisance (like a very large mosquito) in their native habitat. But for the smaller freshwater fish of the Great Lakes, the sea lamprey’s bite is often fatal.

Sea lamprey attached to a salmon
Photo by M. Gaden/Great Lakes Fishery Commission

Why are sea lamprey harmful to the Great Lakes?

The vampire-like fish was first seen in Lake Ontario in the mid-1800s, but it wasn’t until the 1930s that sea lampreys were documented in all five lakes. Gaden says sea lampreys entered the Great Lakes through man-made canals, and the Great Lakes happened to serve as the perfect habitat for the invasive creatures. It provided them with optimal spawning grounds, a plethora of tasty fish, and most importantly, a lack of natural predators. “That’s kind of the best recipe you could possibly have if you’re an invasive species,” says Gaden. “Those are the best conditions for an invasion.”

Gaden says prior to the late 1950s, sea lampreys inflicted enormous damage to the ecosystem of the Great Lakes. Individual sea lampreys are capable of killing 20 kilograms of fish and each female can lay 100,000 eggs. After their invasion, sea lampreys quickly decimated the fish populations of the Great Lakes. “They put some commercial fishers out of business,” says Gaden. “In some cases, they were eating more fish than humans were catching.”

In 1954, Canada and the U.S. joined forces to create the Great Lakes Fishery Commission, which they tasked with managing the Great Lakes ecosystem and containing sea lamprey populations. Gaden says the creation of this bi-national organization is a testament to how destructive the sea lamprey is. While the commission has had success and setbacks over the past half a century, today, lamprey numbers are only at a small fraction of what they were prior to control efforts, he says. 

The secret weapon in the fight against lampreys? Lampricide. Lampricide is a pesticide discovered by the Commission that kills lampreys while leaving other wildlife in the Great Lakes unharmed. “It’s a wild success story in terms of taking a species that essentially posed an existential threat to the Great Lakes, and bringing it under control using mechanisms that are safe for the environment and harmful to lampreys,” Gaden says.

It’s crucial that conservation efforts continue to ensure sea lampreys don’t expand beyond the Great Lakes, says Docker. 

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Cottage Life

Join the cause to spy on feral swine

Photo by Shutterstock/Budimir Jevtic

Wild pigs roaming around Ontario? It may sound harmless, but these feral hogs are no joke. In fact, they’re highly invasive and have been known to topple agricultural businesses and devastate ecosystems. That’s why the Invading Species Awareness Program (ISAP) is working hard to make sure the pigs don’t make Ontario their new home.

ISAP, which was launched in 1992 as a collaboration between the Ministry of Northern Development, Mines, Natural Resources, and Forestry and the Ontario Federation of Anglers and Hunters (OFAH), rolled out its Wild Pig Surveillance Program last year. The program is an effort to broaden its scope of monitoring in Ontario, in response to concerns about the expansion of the Eurasian wild boar, which was introduced here as livestock in 2001.

As part of the program, ISAP created surveillance kits that it shipped to 50 volunteers throughout Ontario. Thirteen surveillance kits were set up in Lanark County near Ottawa, and 40 were set up around Parry Sound. The surveillance kits include a Spypoint Trail Camera, a Spypoint Lockbox, a Python Lock, two 16 gigabyte memory cards, and an information sheet on wild pig detection protocols.

The goal is to identify and round-up any groups of wild pigs (known as sounders) before they become established within the province. “These things are extremely destructive. They will cause huge amounts of economic loss to agriculture as they pillage farms,” says Brook Schryer, who works for ISAP as part of the OFAH. “They’re also a threat to native species because they’re a non-selective omnivore. These things are voracious. They eat a lot, and they will eat whatever they find.”

In rare cases, wild pigs have also been known to attack and kill humans.

Wild pig populations have established themselves in many southern states, including Florida and Texas. ISAP estimates that the pigs account for approximately $1.5 billion in economic losses to the agricultural industry each year in the U.S.

There are also reports of sightings in Minnesota and Manitoba, Schryer says, two regions that border Ontario. Once established, it can be extremely difficult to get rid of the wild pigs as they reproduce every six months, giving birth to litters of four to 10 piglets.

“They’re also exceptionally intelligent,” Schryer says. “They can understand when they’re being hunted. Let’s say it’s during the day, they’ll start to adapt by being more nocturnal because they understand that they’re not being hunted at night.”

“The reason why we put cameras in those locations was strategic,” Schryer says. “There was a wild pig jaw that was found in Lanark County the year prior. So, we knew that there could hypothetically be wild pigs there.” ISAP chose Parry Sound because the region covers a large swath of land and there were a number of keen volunteers in the area.

The surveillance kits captured over 77,000 images, none of which included wild pigs. Instead, ISAP received thousands of wildlife photos of black bears, deer, moose, and other non-invasive species, Schryer says.

Beyond the surveillance, ISAP did receive 34 reports of the invasive pigs through its hotline and website. This includes the 14 Eurasian wild boars that were rounded up just north of Pickering last November.

In 2022, ISAP expanded its surveillance program to northern Ontario. “There’s fewer eyes up in northern Ontario, so we wanted to get these cameras out there,” Schryer says. ISAP’s range of surveillance now stretches from Thunder Bay almost to the Manitoba border. The program taking applications for volunteers to set up monitoring kits. “Anybody who has a hunt camp or anything like that, we encourage them to receive a kit and get them out there.”

So far, ISAP has received three or four reports of wild pig sightings in 2022. “The majority of reports that we have seen in Ontario have been domestic pigs that have escaped,” Schryer says. “In most circumstances, the government is able to follow up and ensure that the pigs are getting back to the rightful owners.”

If you spot a wild pig, you can report it to ISAP by calling 1-800-563-7711 or through this website.

 

Categories
Cottage Life

Fighting phragmites? Here’s a success story to inspire you

Photo by Maxal Tamor / Shutterstock

It was six or seven years ago when cottagers Jim and Joan Rose noticed some new plants growing beside their dock on White Lake, Ont. “We loved to watch them send out runners along the sand,” says Jim, the president of the lake’s cottager association. Then, one day in 2017, Jim’s cousin, Mary Hewitt—an ecologist—was visiting the lake. She broke the bad news: these tough, reedy plants were likely invasive phragmites. “In very short order, we decided that we had a problem,” says Jim.

Jim secured funding from the Federation of Ontario Cottagers’ Associations to buy cutting tools. Then he sent out the cry for help. “The cottagers here are very much committed to maintaining the purity of the lake,” says Jim. “We had 25 people on our deck in four days.” 

5 invasive species and what to do with them

The volunteers worked in small groups, regularly cutting the plants and transporting them to firepits on shore for burning. The crews kept logs: in 2017, they spent a total of 328 hours on the project. “We had such success that, the following summer, we only had to spend 94 hours cutting and burning phragmites,” says Jim. Two years later, “we had pretty much eliminated the invasive from our lake.”

It sure wasn’t easy. “There we were, waist-deep in water, cutting down phragmites towering above us by seven feet. Then we’d spend hours kayaking against the wind, towing rowboats filled with stalks. There were times when we were in despair,” says Jim. “But then, miraculously…we had done it.”

This story was originally published as part of the collection “Better Together” in the June/July 2020 issue of Cottage Life magazine.

A new weapon in the fight against invasive phragmites

Find more resources from the Ontario Invasive Plant Council

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Cottage Life

‘Keep your distance’ from invasive pigs roaming in GTA: MNRF

Photo by Shutterstock/yhelfman

Ontario officials are devising pig snaring plans after a highly invasive species has been spotted roaming free east of Toronto. According to the City of Pickering, locals have reported sightings of 14 Eurasian wild boars in north Pickering since November 5.

“Wild pigs are not native to Ontario and they are known to cause wide-scale devastation to wildlife and ecosystems and can cause negative impacts to Ontario’s agriculture sector,” said Ministry of Natural Resources and Forestry (MNRF) representative Morgan Kerekes in an email.

Eurasian wild boar, native to Eurasia and North Africa, can grow as large as five feet in length and weigh up to 420 pounds, according to the government of Ontario. Throw in razor-sharp tusks and an omnivorous appetite and you have an imposing species.

The wild pigs are not believed to be established in the area—meaning they’re not self-sustaining or breeding—but the MNRF is working with the City of Pickering to investigate the sightings and are prepared to remove the wild pigs when found.

If left to roam, Kerekes said the animals will damage the local ecosystem in the following ways:

  • Preying on native plants and wildlife.
  • Driving wildlife out of their habitats while competing for food and water.
  • Destroying habitats with their rooting and wallowing behaviour.
  • Spreading disease to wildlife, livestock, and even humans.
  • And damaging private property and agricultural crops

Wild pigs are also known to have high reproductive potential, meaning their population can increase quickly, Kerekes said.

The origin of Pickering’s wild pigs is unconfirmed, but city officials have theorized that the animals either escaped from a nearby farm or were released into the wild. While not native to Canada, Eurasian wild boar were introduced into Ontario farms in the 1980s as an exotic meat option.

As with all wild animals, the pigs can pose a threat to people. While there have been no reports of wild pigs attacking anyone in Ontario, Kerkes said, there have been instances in other jurisdictions where wild pigs have shown aggressive behaviour towards people, livestock, and pets. A 2019 encounter proved fatal for a woman in Texas.

“If you see a wild pig, keep your distance, do not feed them, and keep your pets leashed,” Kerekes said. “If a wild pig poses an immediate threat to personal safety and exhibits threatening or aggressive behaviour, call 911 or your local police.”

Kerekes also stressed the importance of reporting wild pig sightings to the MNRF, particularly among hunters who spend time in the environments where the animals live. If you do spot a wild pig in Ontario, report the sighting by emailing wildpigs@ontario.ca, submit it to the iNaturalist Ontario Wild Pig Reporting page, or call 1-833-933-2355.