Montreal conservation group angered after Monarch butterfly fields mowed

A Montreal conservation group is baffled and frustrated after a field of shrubs, flowers, and, importantly, milkweed was mowed, threatening local bird populations and Monarch butterflies, they say.

But the Technoparc near the Trudeau airport, which owns the land, say that particular patch wasn't home to Monarchs nor ecologically sensitive, though the Technoparc has set aside other land for protection.

A group called Technoparc Oiseaux calls the land in question "Monarch fields" and says it was razed this week. It wants to know why, and whether the act violates the Migratory Bird Treaty in Canada and the U.S.

"We were dismayed to discover that the fields had been mowed in the middle of nesting season," reads a Technoparc Oiseaux release.

"We know, thanks to eBird and our own observations, that 150 species of birds can inhabit the Champ des Monarques and golf Dorval."

Environment and Climate Change Canada says migratory birds' nests are protected year-round and that "it is prohibited to damage, destroy or remove a non-active nest without a permit or an authorization."

The website and app eBird allows amateur and professional birders to log and track sightings by location. The Technoparc in Montreal is a popular location with birders catching common and rare species on a daily basis.

Woodpeckers, flickers, swallows, and killdeers are spotted there, as well as falcons, kestrels, and herons. The site drew dozens of eager birders with binoculars and cameras this fall when a scissor-tailed flycatcher showed up, far from its usual home in Texas.

Technoparc Oiseaux says that over 4,000 milkweed plants were shredded on the 19-hectare, abandoned federal land north of the Dorval Golf Course, leased by ADM (Aeroports de Montreal).

Before and after photos of the Monarch Fields in the Dorval Technoparc where a conservation group says thousands of milkweed plants were cut during nesting season. SOURCE: Technoparc Oiseaux

The land in question has been left untouched and undeveloped since 2012, and is "an invaluable ecological environment for both field fauna and flora and for its connectivity to sections of wooded wetlands," the group said.

The milkweeds are particularly important to Monarch butterflies' survival, it said. Monarch butterflies lay their eggs on milkweed which hatch and the caterpillars eat the plant.

The group points out that other species of birds, snakes, mice, shrews, and insects live on the field.

The ADM didn't respond at first to the accusations. But on Monday, it said the patch of land was cut normally, not razed, and that it had little ecological value, even though it's recognized the ecological importance of some nearby spots.

"Two weeks ago, ADM’s maintenance crew mowed the grass in a section of the airport site, specifically because of the presence of ragweed and tall grass, which are nuisances," ADM wrote in a statement to CTV News.

"Our crews certainly did not 'raze' the land, as alleged by some groups, but cut the grass as is standard for normal airport site maintenance operations."

That patch of land used to be part of the golf course and is "brownfield land, zoned industrial," the airport authority said, not a wetland and not a plot that has sensitive species.

"There are no 'monarch fields' at this particular location," it wrote.

"The geographic location of the site, its history, and the low presence of milkweed do not have any critical habitat attributes. In fact, have been no reports of monarch butterflies at this location on the Monarch Mission website in 2022."

It pays careful attention to the local ecology, it said, pointing out it became the only airport authority in Canada to have created protected parkland when it opened Des Sources Ecological Park last year, after announcing the move in 2019. 

Within the Des Sources park, the ADM has also put special effort into the Monarch population, it wrote, working with the group Miel Montreal to dedicate certain spaces to the butterflies and planting specially picked native seeds to 10 per cent of these set-aside areas.

But Technoparc Oiseaux said it wanted stronger protections.

In 2019, the City of Montreal became the first Canadian city to be granted GOLD monarch-friendly status, and the group asked this week why an area like one that got plowed is not also protected.

"We must act now to ensure that our green spaces are protected to ensure a healthy future to our children, our fauna and our flora," the group said.