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I About Mont St. Hilaire I Diversity of Habitats I Diversity of Organisms I


About Mont St-Hilaire

Mont Saint-Hilaire is a prime example of a mature forest ecosystem which has remainedMSH.jpg almost untouched since European colonization. Bowl-shaped, with numerous peaks along the outer edge and a lake at its centre, it is one of the rarest forests in Québec and has a rich variety of habitats. Owned privately until 1958, the 2300 acres were bequeathed to McGill University by Andrew Hamilton Gault " a great heritage for the benefit and enjoyment of the youth of Canada". The property is divided into two zones, the east side of the mountain, to be preserved and used for research, and the west side, to be used for public recreation and nature interpretation.

Given the area's natural qualities, the long period of protective management, and the success of recent scientific and educational initiatives, Mont Saint-Hilaire was designated in 1978 as Canada's first UNESCO (United Nations Educational, Scientific and Cultural Organization) Man & Biosphere (MAB) Reserve. The MAB sites are a worldwide network of benchmark reserves critical to deciding the needs for the sustainable development.

For more information, go to the McGill Mont St. Hilaire website:

Diversity of habitats

The MSH reserve is characterized by a variety of different habitats both aquatic and terrestrial. Below is a brief description of the types of habitats found on the mountain, beginning at the central lake and moving up to the summits of the mountain.

At an elevation of 173 metres and almost central on the mountain, Lac HertelLac Hertel.jpg has an approximate area of 0.3 square kilometres and a maximum depth of 9 metres. Rain and melted snow nourish the brooks of the inner basin, and it is this water that fills Lac Hertel. This clean and unpolluted shallow lake acts as an auxilliary drinking water reservoir for neighbouring communities. The bottom of the lake is muddy and the shallow waters support a thick growth of rooted aquatic plants, forming an aquatic jungle for teeming populations of fish, frogs and invertebrates. Trees and shrubs bordering this area shelter birds and small mammals. South Creek, the outlet from Lac Hertel, dwindles from a spring flood to a mere trickle by the end of summer. It provides a variable seasonal habitat for larval insects and for other invertebrates, which in turn are food for a variety of fish, birds and mammals.

MSH water's edge.jpgWhere open lake and forest meet is an overlapping band of moisture-tolerant trees and shrubs which crowd to the water's edge seeking sunlight. The mixed conditions here offer added opportunities for living organisms, thus attracting a greater variety of species. The marshy area of Botany Bay at the eastern edge of the lake acts as a breeding site for the rare pickerel and chorus frogs.


MSH -old-growth forest.jpgAlmost the entire mountain harbours a mature hardwood forest composed mainly of beeches and maples with occasional pockets of other deciduous trees or evergreens. The forest canopy forms a distinct habitat extending between 10-20 metres above the ground, where insects flourish. It also provides safe nesting, perching and feeding sites for many species of birds, as well as a playground for squirrels. Shade from the canopy profoundly affects the plants of the understorey and consequently the activities of all the animals which make their home on the forest floor.

The forest floor comes alive in the spring before the leaves in the forest canopy grow and shut out the light. Many flowering MSH-forest floor with trilliumsplants which require strong sunlight to blossom and seed are visible at this time. Fallen leaves and twigs form the top layer of the soil and along with humus and other organic matter play an important role in soil fertility. Below this is a dark-coloured layer of decaying material occupied by small organisms such as bacteria, fungi and mites. These organisms are all working to break down the litter into nutrients which can be used by plants and trees.

Most ferns, mosses and fungi prefer cool moist soil, and in favourable areas such as the Devil's Gorge, the ostrich fern (Matteuccia struthiopteris) reaches heights of 1.5 meters. In very wet areas the tree growth is slow. Tree species adapted to wet sites include red maple (Acer rubrum), black ash (Fraxinus nigra), shagbark hickory (Carya ovata) and basswood (Tilia americana).

In certain areas of the mountain, fire or human settlement has drastically affected the environment. In the case of the large meadow, the forest was cleared in the early days to create an apple orchard which failed to adapt to the poor soil. Now this area has become a temporary meadow in which sun-loving plants have taken hold. In about 50 years this open field will mature into forest.

MSH summit.jpgAt the exposed summits, 400 meters above the surrounding plain, strong winds and cooler temperatures combine to limit the vegetation. Only lichens cover the rocks and the three-toothed cinquefoil (Potentilla tridentata) grows in between the crevices.



Diversity of Organisms

| Birds | Mammals | Trees | Plants | Fish | Amphibians and Reptiles |


The number of birds that are observed on Mont St-Hilaire varies with the seasons: over 130 species of birds are observed during spring migrations from the south, 101 in summer, 136 in autumn as birds migrate back south and 37 in winter. A total of 83 species nest on the mountain. The mountain is a well-known stopover site for canada geese. Every autumn, particularly during September and October, approximately 200 birds rest on Lac Hertel every night and fatten up on the surrounding fields during the day.

peregrine.jpgMany rare and interesting bird species are found at the summits. Since 1985, a pair of peregrine falcons has nested on a cliff near Dieppe peak. Mont Saint-Hilaire is one of only ten peregrine nesting sites known in Québec. Conditions have to be just right, with the nesting area providing protection from wind and rain, and easy access to other birds such as pigeons, since peregrines capture their prey in the air. Near this site, a pair of ravens nest in early spring. Large hawks as well as golden and bald eagles fly around the peaks in early spring, but do not nest on the mountain. Rufous-sided towhee, a rare bird in Québec, has also been sighted on the summits. Other rare sightings include the colourful indigo bunting and cerulean warbler. In addition, at least two pairs of turkey vultures nest in caverns created by rock-falls. Approximately 10 - 20 individuals gather and swoop through the warm air currents at the higher altitudes during the summer. The pileated woodpecker.jpgred-shouldered hawk, listed as vulnerable in Québec, and the barred owl, are found in the forest. There are at least two couples of barred owls that reside on the mountain year round and feed on small mammals and amphibians. Three species of woodpecker, the downy, hairy and pileated, are common in areas with larger trees. Migratory insectivorous birds such as the yellow-bellied sapsucker and the northern flicker are also common. Black-capped chickadees are common in coniferous trees and the ruffed grouse is found rummaging in the forest litter.



Mont Saint-Hilaire provides habitats for a variety of animals, ranging from the extraordinarily common chipmunk to the shy deer. Each plays a vital role in the forest community; burrowing animals like chipmunks improve the aeration and quality of the soil and predators such as the fox have prevented the overcrowding of prey which can adversely affect vegetation. Red and grey squirrels are the most common small mammals here but inhabit completely different areas: the red squirrel inhabits coniferous trees and eats pine cones while the grey squirrel favours the nuts of the beech, oak and maple groves.

Two dozen deer are known to live around the base of the mountain and forage on the vegetation on the east side towards Sainte-Madeleine. They especially enjoy cedar hedges and trees red squirrel.jpgare often defoliated to the 2.5 - 3 metre level. A handful of active dens of the red fox have been found. Other predators include two species of weasel, the mink and the ermine. The most common hibernating mammals to be found are the chipmunk and the raccoon. Although groundhogs are common in the banks of open areas such as the meadow they are capable of burrowing anywhere. The porcupine, common in the hemlock groves, does not hibernate and can be seen year round. Rabbits are also active year-round in open meadow areas, and snowshoe hares frequent the higher slopes.

Small mammal list from R.E. Wrigley, 1967(The mammals of southwestern Quebec (south of the St. Lawrence river), M.Sc. thesis, McGill University):

smoky shrew (Sorex fumeus )

short-tailed shrew (Blarina brevicauda)

little brown myotis [bat] (Myotis lucifugus)

silver-haired bat (Lasionycteris noctivagans)

big brown bat (Eptesicus fuscus)

grey squirrel (Sciurus carolinensis)

red squirrel (Tamiasciurus hudsonicus)

groundhog (Marmota monax)

eastern chipmunk (Tamias striatus)

deer mouse (Peromyscus maniculatus)

white-footed mouse (Peromyscus leucopus)

southern red-backed vole (Clethronomys gapperi)

meadow vole, field mouse (Microtus pennsylvanicus)

woodland vole, pine vole (Microtus pinetorum)

woodland jumping mouse (Napaeoapus insignis)

porcupine (Erethizon dorsatum)

red fox (Vulpes vulpes)

ermine (Mustela erminea)

long-tailed weasel (Mustela frenata)

raccoon (Procyon lotor)

striped skunk (Mephitis mephitis)

white-tailed deer (Odocoileus virginianus)




Mont St-Hilaire is a maple-beech climax forest, the final and most stable community in this forest ecosystem. The co-dominant species which from the canopy are american beech (Fagus grandifolia) and sugar maple (Acer saccharum), two species which are highly shade tolerant at the seedling stage. Tyellow birch.jpghe Beech is commonly found on moist, well-drained slopes and ridges and is usually mixed with other native hardwoods. Sites including stands composed almost entirely of beech are also found. Beech is a tree with persistent and acid leaves; they fall to the ground and decompose very slowly. The sugar maple is one of the tallest hardwoods in Canada, sometimes reaching a height of 40m and a diameter of 1.5m. The trunk is usually long and straight in the forest, short and branched in the open.

Hickory, an indicator species for a healthy, stable and old forest, occurs throughout the mountain but does not form stands.

In some areas the mature forest is being rejuvenated by hemlock (Tsuga canadensis). Hemlock seedlings require shade provided by other trees for growth to occur. The eastern hemlock is a medium-sized tree, 20m in height and 50-60cm. in diameter. This tree is often mixed with white pine, spruces, balsam fir and various hardwoods. Birch trees are characteristically found at the edge of forest where they lean towards the light.

The white birch (Betula papyrifera)is a species that prefers light; it is found in open areas and has difficulty reseeding in the shade and so is found in the open or at the edge of the forest. White birch are usually associated with young forests because they need a lot of sun. The grey birch (Betula populifolia) is usually found on dry gravelly or sandy soils and is often one of the first trees to spring up after a forest fire. It is a small tree and rarely grows over 9m tall or 15cm in diameter. The yellow birch (Betula alleghaniensis) is the largest of Canada's birches. The average tree is 20m high and 60cm in diameter. It grows on a wide range of sites.

On wet sites in the valleys where tree growth is slow the common species include red maple, black ash, shagbark hickory and basswood. Red maple (Acer rubrum) attains a height of 25m with a maximum trunk diameter of over 1m when growing in moist soils. Although a common tree throughout its range, it is not plentiful at Mont St-Hilaire. The tree is distinctive for it red twigs, winter buds, flowers and fruits and leaf stems. The basswood, also known as linden (Tilia americana), is 20m in height and 60-75cm in diameter. It prefers a deep loam soil on low slopes and along streams, but is also found on high rocky ridges.

The valleys between the eleven peaks are wind corridors and mark areas where there is constant renewal and regrowth on the slopes. The vegetation of the summits are also affected by wind and the most common species is the dwarfed red oak.

The attractive striped maple, or moosewood (Acer pennsylvanicum), is often found in the understorey associated with beech. Moosewood has no commercial value for wood but its leaf litter is very high in nutrients like potassium and calcium. This tree is a tall shrub or small tree, commonly 3-6m in height. It prefers cool moist soils on northern slopes and in valleys where it is protected from direct sunlight. At Mont St-Hilaire it forms a large part of the shrubby understory beneath mixed stands of beech and sugar maple. The buds and twigs provide winter food for deer and moose and the latter eat the leaves in summer.

The Mountain maple (Acer spicatum)is a small tree or shrub rarely more than7.5m in height and 12-18cm in diameter. At Mont St-Hilaire it prefers rich soils on moist, rocky slopes and flats, and along small streams, where it frequently forms the major part of the shrubby undergrowth. It is rarely found growing in the open. The tree prevents erosion on rocky slopes because the root system is very shallow.

Red ash (Fraxinus pennsylvanica) is commonly found on moist sites along streams, on the margins of swamps and on hillsides, where it grows with other hardwoods.

Red oak (Quercas rubra var. borealis)is a large tree,18-24m in height and 60cm-1m in diameter. It is a very rapid growing oak and will do well on a variety of soils. It is only moderately tolerant of shade and is often found on sandy loam or rocky sites. Red oak covers the summits of Pain du Sucre and Dieppe but as a low and scrubby dwarf.

The Pin or Fire Cherry (Prunus pennsylvanica)is a small tree, 3-8m high and 10-20cm in diameter. On Mont St-Hilaire it is found on new clearings and on burned-over areas in a wide variety of soils from dry sand to wet loams. It is very intolerant of shade. The tree is quite useful in preventing erosion on newly cleared forest land and in providing a light shade for the seedlings of more tolerant species.

The eastern white cedar (Thuja occidentalis) is a small tree averaging about 13m in height and 30cm in diameter. At Mont St-Hilaire this tree is commonly found near swamps, around springs and lakes and on similar wet sites but it will also thrive on the thin, often dry, soil of limestone ridges.

The eastern white pine (Pinus strobus) is thwhite pines.jpge tallest and most stately of all conifers in Eastern Canada. It sometimes reaches a height of 55m and a diameter of 1.5m It will grow on a wide range of sites from dry sandy ridges to wet sphagnum bogs, but does best on a moist, sandy soil. At Mont St-Hilaire it reaches its greatest size on rich loams with eastern hemlock, yellow birch and sugar maple.

The apples, cherries, plums, hawthorns, serviceberries and mountain ashes are all members of the rose family of which the apples are well-known and widely distributed representatives. About 25 species of apple are known. The common apple (Malus pumila) has been introduced into Canada for its fruit and is now naturalized under the name of wild apple in many parts of the conntry. It is the parent of many of the present-day cultivated apples.


Mont St-Hilaire columbine.jpgshowcases a total of 551 different taxa of plants. Of these 551 taxa, 34 are trees, 65 are shrubs, 6 are lianas, and 421 are herbs. 23 species are more or less restricted to aquatic environments.

The largest family represented is the Compositae (11%), followed by Rosacae (7%), Cyperaceae (7%), Graminae (7%). The ferns, including members of three families, number 38 species (6%).

Mont St-Hilaire occupies a central location between the Northern Conifer-Hardwood/Northern Conifer regions of eastern N.A and the boreal forest further north.

The most common plants in the understorey and highly visible in the early spring when they flower include the moccasin flower, yellow lady's slipper, the trillium and the wood violets. In late summer the marsh-touch-me-not or jewelweed are very common in the wetter areas.


248 Lichen and Moss taxa are found on Mont St-Hilaire. Lichen are a combination of algae and fungi that live on and break down bare rocks, creating a substrate for plants. Mosses are primitive plants often found as a rich carpet over ground and rocks. Generally anonymous, properly identifying lichen and moss usually requires an expert and many lichen species can only be idenified by chemical composition. Although not as difficult to identify, mosses are rarely identified to species. Moss genera with the most species are:









Hepatic genera:








Horsetails, also known as rushes, are usually found in or on the banks of streams, but they grow in many disturbed areas as well, such as at the edges of roads and paths. Seven species of horsetails are found at Mont St-Hilaire.

field horsetail (Equisetum arvense)

water horsetail (Equisetum fluviatile)

great scouring-rush (Equisetum hyemale)

meadow horsetail (Equisetum pratense)

dwarf scouring-rush (Equisitum scirpoides)

woodland horsetail (Equisetum sylvaticum)

variegated scouring-rush (Equisitum variegatum)

Many species of clubmoss look like miniature trees, and when a large poplulation is found it resembles a miniature forest. Quite often these populations are formed by a single individual that sends out runners under the leaf litter which sprout up every few centimetres.

flattened clubmoss (Diphasiastrum digitatum)

three-spiked clubmoss (Diphasiastrum tristachyum)

shining clubmoss (Huperzia lucidula)

stiff clubmoss (Lycopodium annotinum)

running clubmoss (Lycopodium clavatum)

tree clubmoss (Lycopodium dendroideum)

tree clubmoss (Lycopodium obscurum)



Ferns are found almost everywhere at Mont St-Hilaire, not only in the wetter ferns.jpgareas where they are expected, but also in the sun-baked meadow. Individuals of the genus Botrichium are often so tiny, less than 15cm in height, that they can be difficult to find amongst grass; in contrast, the ostrich fern and cinnamon fern can reach heights of 1.5m by late summer. Thirty-eight species of fern are found on Mont St-Hilaire, some practically everywhere and some in only a half-dozen sites.

american maidenhair fern (Adiantum pedatum)

maidenhair spleenwort (Asplenium tricomanes)

lady fern (Athyrium filix-femina)

dissected grape fern (Botrichium dissectum dissidum)

dissected grape fern (Botrichium dissectum obliquum)

matricary grape fern (Botrichium lanceolatum)

matricary grape fern (Botrichium matricariifolium)

leathery grape fern (Botrichium multifidum)

rattlesnake fern (Botrichium virginianum)

walking fern (Camptosorus rhyzophyllum)

bulblet bladder fern (Cystopteris bulbifera)

brittle bladder fern (Cystopteris fragilis)

hay-scented fern (Dennstaedtia punctiloba)

silvery glade fern (Deparia acrosticoides)

glade fern (Diplasium pycnocarpon)

spinulose shield fern (Dryopteris campyloptera)

spinulose shield-fern (Dryopteris carthusiana)

crested shield fern (Dryopteris clintoniana)

crested shield fern (Dryopteris cristata)

male fern (Dryopteris filix-mas)

goldie's shield fern (Dryopteris goldiana)

intermediate shield fern (Dryopteris intermedia)

marginal shield fern (Dryopteris marginalis)

oak fern (Gymnocarpium dryopteris)

ostrich fern (Matteuccia struthiopteris)

sensitive fern (Onoclea sensibilis)

cinnamon fern (Osmunda cinnamomea)

interrupted fern (Osmunda claytoniana)

royal fern (Osmunda regalis)

long beech fern (Phegopteris conectilis)

rock polypody (Polypodium virginianum)

christmas fern (Polystichum acrosticoides)

braun's holly fern (Polystichum braunii)

bracken (Pteridium aquilinum)

broad beech fern (Thelypteris hexagonoptera)

new york fern (Thelypteris noveboracensis)

marsh fern (Thelypteris palustris)

rusty woodsia (Woodsia ilvensis)




The species of fish found in Lac Hertel include the following eight species:

northern pike (Esox lucius)

rock bass (Ambloplites rupestris)

yellow perch (Perca flavescens)

pumpkinseed sunfish (Lepomis gibbosus)

golden shiner (Notemigonus crysoleucas)

mudminnow (Umbra limi)

white sucker (Catostomus commersoni)

brown bullhead (Ictalurus nebulosis)


Reptiles and amphibians

eastern newt (Notophthalamus viridescens)

blue-spotted salamander (Ambystoms laterale)

yellow-spotted salamander (Ambystoma maculatum)

eastern red-backed salamander (Plethodon cinureus)

leopard frog (Rana pipiens)

american toad (Bufo americanus)

tetraploid gray treefrog (Hyla versicolor)

northern spring peeper (Pseudacris crucifer)

wood frog (Rana sylvatica)

pickerel frog (Rana palustris)

green frog (Rana clamitans)

bullfrog (Rana catesbeiana)

common garter snake (Thamnophis sirtalis)

milk snake (Lampropeltis triangulum)


Text compiled and written by Torsten Bernhardt