Nature on Mount Royal

Our Mountain: So Full of Life!

Mount Royal’s green territory includes three summits, several parks, sweeping cemeteries and large institutional properties. This lush 10 km2 expanse abounds in plant and animal life including the woodlands, wetlands and meadows of Mount Royal Park.

Mount Royal is:

• More than 700 species of vascular plants, some of which are rare and endangered, in the natural habitats
• More than 90 species of trees
• More than 180 species of birds
• Nearly 20 species of mammals
• Two species of amphibians
• Two species of reptiles
• Thousands of different insects

Discover how Mount Royal’s fauna, flora and geology give it a rich and varied nature.
 

Fauna

Mount Royal is one of the few places in Montréal with such diverse wildlife. Mount Royal Park in particular is home to a great number of mammals and birds.
 

Mammals, Amphibians and Reptiles on Mount Royal

Many small mammals, amphibians and reptiles inhabit Mount Royal and benefit from its rich biodiversity. For instance, on any given path, you might see a raccoon or a squirrel jumping from tree to tree, or even spot a red fox running across one of the cemeteries. More sensitive to disturbances, amphibians and reptiles hide out of sight in less frequented places.

Obviously, cohabitation with residents and park users is sometimes difficult and might jeopardize their safety. If you see an animal on the mountain, it is important to keep your distances and especially not feed it. See our information sheet on habitat conservation to learn more about the challenges facing wildlife on Mount Royal.

 

Birds on Mount Royal

Regardless of the season, Mount Royal is a paradise for amateur and professional bird watchers right here in the city. More than 180 bird species visit the Mount Royal territory, more than 100 of which can be observed on a regular basis.

Moreover, Mount Royal Park has a circuit of seven feeders installed along Olmsted Path winding around the summit where several species can be spotted in winter. In addition to offering guided bird-watching tours, Les amis de la montagne takes part in the FeederWatch Project, an extensive volunteer-based North American survey of winter birds that visit feeders. See our schedule to find out about birdwatching activities

 

Flora

Visible from afar, the Mount Royal canopy of mature tree crowns is a significant component of the mountain’s landscape. The various forest stands that compose it include maple, oak and ash groves, for the most part.

The extremely varied flora of Mount Royal has undergone several transformations over time. Given that the best lands were cleared for agriculture purposes, many orchards at the base of the mountain and to Mount Royal’s southwest (now Westmount, Côtes-des-Neiges and Notre-Dame-de-Grâce) were famous for their produce. The creation of two cemeteries and Mount Royal Park in the mid-1800s also greatly altered the plant composition of Mount Royal, in particular through the introduction of new horticultural species.

Today, mostly sugar maple and bitternut hickory trees thrive in the mountain’s Piedmont sector, red oak and white pine on its summits, and white birch on some slopes. In addition to these trees, many of which are over 100 years old, the woodlands of Mount Royal include over 700 plant species contributing to the mountain’s rich biodiversity. Certain rare and endangered plants like the mayapple or other vulnerable plants like the white trillium or bloodroot are also subject to additional protection measures in Mount Royal Park to avoid being picked or trampled.
 

Natural… and Human Threats to the Environment

The flora of Mount Royal experienced numerous upheavals over the years. Notably, in 1950, the municipal authorities in place carried out a radical clearing of the undergrowth to allow better visibility in the forest and control activities that were deemed “undesirable.”

Referred to as “morality cuts,” these interventions greatly damaged the oak grove. As a result, thousands of white spruce and red pine trees were planted to control the erosion of exposed soils, in addition to a large number of Norway maples. Invasive species, such as common buckthorn and wild parsley, appeared and spread on Mount Royal, taking advantage of disturbances caused by felling and planting to invade the undergrowth.

More recently, the 1998 ice storm caused heavy damage to the woodlands of Mount Royal. Approximately 5,200 trees were cut down in Mount Royal Park alone, and another 45,000 trees required significant pruning.

Given the effects of climate change and global warming, the woodlands of Mount Royal are not immune to the arrival of new exotic insects that pose threats to certain tree species. For instance, the emerald ash borer, which first appeared in Montréal in 2011, has already affected numerous ash trees on the mountain, in Mount Royal Park and elsewhere. See our information sheet on the emerald ash borer.

Added to these threats are the numbers of users and visitors hiking off trail, picking plants or practising sports that are harmful to the natural habitats. Learn more about the issues and challenges affecting the protection of natural environments of Mount Royal.

Thanks to natural regeneration and conservation efforts by the City of Montréal assisted by Les amis de la montagne and our volunteers, the woodlands of Mount Royal remain natural havens offering exceptional biodiversity in the heart from the city.

Geology

Although long studied by scientists and scholars, the origin and composition of Mount Royal remain shrouded in mystery and myth for many Montrealers and visitors. Is Mount Royal really an ancient volcano and is Beaver Lake a former crater? What kinds of rocks compose the mountain? And whatever happened to the beavers?
 

125 Million Years Ago: A Mountain Was Born

Part of the Monteregian Hills, Mount Royal was carved by erosion over time.

Approximately 125 million years ago, the earth's crust beneath the Montréal region was disturbed by rising magma, which stopped a few kilometres short of the surface. Dykes were formed as some of the magma pushed up towards the surface, but most of the magma remained trapped under the ancient rock layers before cooling and solidifying into a hard mass of igneous rock.

Over time, erosion caused by wind, rain and glaciers shaped the landscape. Sedimentary layers surrounding the mass of igneous rock were carried away, removing any traces of ancient volcanism. The mass of buried rock, more resistant and therefore less affected by erosion, broke to the surface and formed a hill. Mount Royal appeared.

Consequently, we now know that the mountain is neither a volcanic crater nor created by plate movement.
 

13,000 Years Ago: The Island of Mount Royal?

The last great glacial period affecting North America left its mark. For nearly 80,000 years, glacial erosion shaped the land, giving Mount Royal its present form.

Approximately 13,000 years ago, retreating glaciers formed the Champlain Sea, an ancient inlet of the Atlantic Ocean covering the St. Lawrence lowlands. At this time, Mount Royal’s main summit emerged at 60 m above the water. Along with the other two summits (Westmount and Outremont), it formed a small archipelago on which life gradually took root. The islet was covered in flora similar to the Arctic tundra characteristic of northern Quebec. There were no trees, and the climate was cold and dry.

Over time, the Champlain Sea withdrew and water level fells, revealing more and more land. The first trees, most likely aspen, appeared about 11,000 years ago.

But whatever happened to the beavers of Mount Royal? Gnawed pieces of wood found in the sediments under the current Beaver Lake site revealed that beavers occupied the site 11,000 to 9,600 years ago, for about 1,400 years. Subsequently, lowering the pond and filling in the basin transformed conditions, which became unfavourable to the beavers.
 

Rocks of Mount Royal

The mountain is mainly composed of an igneous rock called gabbro. Also found are Trenton limestone and Utica Shale, sedimentary rocks typical of the Montréal region, dating back to the Ordovician Period (485 to 443 million years ago).

Marine fossils occasionally spotted in Trenton limestone bear witness to a past life in the ocean. Close examination of limestone layers sometimes reveals crinoid stem segments as well as small brachiopods and fragments of coral.

The formation of Mount Royal also caused the appearance of other rock types: rocks in contact with the magma intrusion underwent a recrystallization under the effect of intense heat. Limestone in contact with the intrusion metamorphosed into marble and shale into hornfels.
 

For More Information

For a closer look at the mountain and its geology, take part in our seasonal walking tours.

Geological walking tours on Mount Royal with geologist Pierre Bédard (French only)
 

References

Paleoecological studies in 2012-2013 led by Pierre J. H. Richard, Université de Montréal