My Favourite Places: Mud Lake

Southern Ontario has Point Pelee, Ottawa has….Mud Lake. Officially known as the Britannia Conservation Area, this 79-hectare conservation area consists of woodland, riparian, wetland and upland habitats surrounding a large eutrophic (nutrient-rich) pond known as Mud Lake. This large greenspace is bordered by the Ottawa River to the north and by residential and shopping districts to the south, which makes it an attractive place for migrating birds to stop and rest and one of the largest migrant traps within the city. As a result, Mud Lake has become one of Ottawa’s premier birding spots and the best year-round birding hotspot in Ottawa. About 250 bird species have been seen in this conservation area, or approximately 75% of all species recorded in the OFNC study area (a 50-kilometer radius centered on the Peace Tower). From warblers in the spring to herons in the summer, waterfowl in the fall and raptors year-round, Mud Lake is especially known for its songbird migration in the spring and fall when hundreds of swallows, flycatchers, vireos, thrushes, mimids, sparrows, blackbirds, finches, waxwings, grosbeaks, wrens and, of course, warblers descend on the conservation area. It’s had more than its fair share of rarities, too, including Eurasian Wigeon, Harlequin Duck, Little Blue Heron, Forster’s Tern, Gray Kingbird, Connecticut Warbler, Yellow-throated Warbler, and Yellow-breasted Chat (none of which, I might add, were seen by me).

Map of Mud Lake

Google Map of Mud Lake

I started visiting Mud Lake in August 2006 as a relatively new birder with a life list of about 57 birds. I was awed the first time I went, for there were so many birds flying back and forth in the trees above Cassels Street and lurking in the thickets bordering the lake that I didn’t know where to look first, nor how to identify most of them! Since then I have added a large number of species to my life list – many of them seen for the first time at Mud Lake – and have counted over 130 species in the conservation area.

It was during that first visit that I discovered the ridge, a narrow, elevated rise of land between Cassels Street and the river and one of the best places to see migrants. The ridge is filled with trees and dense thickets, but trails lead over it and along the top, providing excellent views of the birds flitting about in the vegetation. I often start my visits here, parking on Cassels Street and then walking along the top of the ridge. Most of the songbird and raptor species I’ve observed at Mud Lake have been seen on or from the ridge, making it the best one-stop birding spot in the entire conservation area. From there I usually take the trail to the river behind the ridge. There is a long island just offshore, so the trail doesn’t look right out onto the open river but rather a narrow channel that is usually free of ice all year round.

Carolina Wren

After birding the ridge and the river, I usually check the trails along the west side of the lake as they are often the most productive. The main trail runs along the water’s edge through a hardwood stand of maple, oak and ash before entering an area dominated by mature white pines. There is an observation dock here that looks out onto the lake, providing good views of the waterfowl. A secondary trail runs north-south through an old field dominated by grasses, honeysuckle, buckthorn, and staghorn sumac. If time permits, I occasionally like to walk all the way around the lake, crossing the bridge at Turtle Bay before proceeding through another dry, open area characterized by buckthorn shrubs and sumacs, into a swampy wooded area, and finally behind the water filtration plant at the northeast corner of the conservation area. The point behind the filtration plant offers good views of the river below Deschenes Rapids and is an excellent spot to see waterfowl on the river. Red-breasted Merganser, Bufflehead, Long-tailed Duck, White-winged Scoter, Lesser Scaup and Red-necked Grebe have all been seen here. Arctic Terns occur annually in this spot in the spring, and on October 22, 2011 a Razorbill was seen swimming in the waters beyond the point! A bird of the Atlantic Ocean, the Razorbill spent a couple of weeks on the river between Deschenes Rapids and the Champlain Bridge.

The variety of habitats and its position as an isolated greenspace in the middle of the city provide not only food and shelter to large numbers of tired migrants, but also nesting habitat to over 50 different species of birds as well as many other types of wildlife. Many different mammals can be found here year round, and in the warmer months, Mud Lake is known for its large turtle population as well as its variety of odonates. A total of 69 species of damselflies and dragonflies have been found here to date, making it one of the most diverse areas in the city.


Scilla in the Spring

Spring begins as soon as the Red-winged Blackbirds and Common Grackles arrive, usually in mid-March, but my favourite time to visit is in mid-April through the entire month of May. By then the lake is ice-free and the Wood Ducks have returned, and the woods are carpeted with wildflowers such as Bloodroot, Trout Lily, Scilla and Glory-of-the-Snow. Eastern Phoebes, Song Sparrows, Northern Flickers, Ruby-crowned Kinglets, and perhaps even an early Black-crowned Night-heron will all have arrived, as well as the first Yellow-rumped and Pine Warblers. Newly emerged flying insects provide a bounty for swallows and Chimney Swifts, while on the river Buffleheads, Common Goldeneye and Hooded Mergansers may be seen diving for fish.

Male Wood Duck

By late April the resident turtles will have emerged from their hibernation. Look for them basking on logs along the southern shore of the lake. A small bridge crosses over a bay where over 100 turtles may be seen basking on warm, sunny, spring days; while the vast majority are Painted Turtles, sometimes large Snapping Turtles or the endangered Blanding’s Turtle may be spotted among the smaller turtles. Look for Wood Ducks and muskrats in this area as well.

Blanding’s Turtle

May is best of the spring months for visiting Mud Lake. Baltimore Orioles, Gray Catbirds, Brown Thrashers, American Redstarts, Yellow Warblers, Warbling Vireos and Red-eyed Vireos are all back on territory and can be heard singing throughout the conservation area. Good numbers of other warbler species can also be found in the woods and along the ridge, including Blackburnian Warblers, Magnolia Warblers, Blackpoll Warblers, Tennessee Warblers, Black-throated Blue Warblers, Palm Warblers and Northern Parulas. Once I’ve even seen a Northern Waterthrush lurking in the tangles along the shore of Mud Lake. Non-warbler passerines such as Least Flycatchers, Rose-breasted Grosbeaks, Scarlet Tanagers, White-throated Sparrows and Hermit Thrushes are common, and once even a Northern Mockingbird (May 6, 2007) dropped in for a visit!

Check the woods near the observation dock for Cooper’s Hawks; a pair has bred here for the last few years and are often seen in this area in the early spring until their young have fledged. Other spring raptors include fly-overs of Northern Harrier (two on March 15, 2009), a juvenile Bald Eagle (April 12, 2009) and Broad-winged Hawk (May 19, 2012). Ravens have also nested in the pine trees by the observation dock for the past few years, and the young often reveal the location of their nest by their loud, incessant cries in the period between hatching and fledging. Common Terns and Osprey can sometimes been seen hunting over the lake itself.

Beaverpond Baskettail

Beaverpond Baskettail

May is also the month when my favourite insects, the dragonflies, emerge. Beaverpond Baskettails are abundant some years, especially in the old field west of the pond. American Emeralds and Common Green Darners are often present as well, while Dot-tailed Whitefaces begin to appear on lily pads floating on the lake.


Mud Lake

During the early part of the summer, the conservation area is often quiet as the birds are focused on raising their young. The lake is home to many breeding pairs of Wood Ducks, mallards and Canada Geese, and by late May/early June you can see long lines of ducklings and goslings following their parents on the water. One year I even saw a trio of tiny Hooded Mergansers diving in a quiet spot with their mother! Juvenile herons begin to appear in the summer, with four species represented: Great Blue Herons, Great Egrets, Green Herons, and Black-crowned Night-herons. A walk around the lake will produce most of these species.

Summer is a great time to look for odonates. Widow Skimmers, Twelve-spotted Skimmers, Common Pondhawks, and (for the past two years) Blue Dashers are abundant during the summer months, with White-faced Meadowhawks, Canada Darners, Lance-tipped Darners becoming more common toward the fall. A Dragonhunter seen in July, 2010 was a lifer for me, as well as the first confirmed living specimen observed at Mud Lake.

Great-crested Flycatcher

Some interesting species may turn up in July as a result of post-breeding dispersal. Veeries do not breed at Mud Lake, yet one turned up in July 2011. Many birds tend to leave their breeding territories and wander after they have finished raising their young, seeking new, food-rich places where there is less competition for the same resources. A Black-and-white Warbler seen another time in July may have been a local breeder or a wanderer from another site.

Black-and-white Warbler


The western shore of Mud Lake

My favourite time to visit Mud Lake is in the fall. By the end of August the first migrants show up, and keep moving through until late October or early November. There seems to be not only a greater number of birds in the fall, but also a greater variety of species. In fact, many species that stop in at Mud Lake seem to be easier to find here in the autumn than in the spring, including Ring-necked Ducks, American Wigeon, Philadelphia Vireos, Blue-headed Vireos, Fox Sparrows, my one-and-only Field Sparrow, Wilson’s Warblers, Canada Warblers, Bay-breasted Warblers and Winter Wrens. Juvenile Rose-breasted Grosbeaks, Cedar Waxwings, Gray Catbirds and Northern Cardinals are plentiful along the ridge, foraging with most of Ottawa’s twenty-plus warblers. The different warbler species are easier to pick out in late August, before the numerous Yellow-rumped Warblers descend on Ottawa in September and greatly outnumber everything else.

Eastern Screech Owl

In late August the first Great Black-Backed Gulls can be seen loafing on the rocks of Deschenes Rapids. Falling water levels can reveal some interesting birds among the rocks, including Common and Hooded Mergansers, numerous Ring-billed and Herring Gulls, and the occasional Spotted Sandpiper. This is also the time of year when Common Nighthawks being moving through the region; they can be seen flying over the conservation area late in the afternoon, looking like small falcons with a tell-tale white spot on the underside of each wing.

Beaver at Mud Lake.


The Ottawa River behind the Ridge

Even in the winter a trip to Mud Lake can be rewarding. Foxes, rabbits, porcupines, weasels, beavers, squirrels, mice and voles are active all year-round, and their tracks are often visible in the snow. Sometimes I even encounter the animal itself; I have seen a fox being harassed by crows before bounding off across the ice-covered lake, a beaver carrying branches into an underwater cache behind the ridge, and a Short-tailed Weasel scurrying across the ridge one December before enough snow had fallen to provide him with any camouflage.

Short-tailed Weasel

Black-capped Chickadees, Pileated Woodpeckers, House Finches, Dark-eyed Juncos, Common Goldeneyes, Mallards and American Black Ducks all spend the winter here, and because of the abundance of berries throughout the conservation area, flocks of American Robins, Cedar Waxwings and Bohemian Waxwings can usually be found most winters here as well.

Winter Robin

Other birds may attempt to overwinter here, too. In the fall of 2011 a Carolina Wren was discovered in the woods along the western fence-line, and as far as I know he is still there. I went to see him one day last January, and found not only the Carolina Wren, but also a Winter Wren and a Belted Kingfisher behind the ridge! These were both very unexpected birds, for I’d never seen either species in the middle of winter before. Another time I found a Hermit Thrush hanging out with a flock of robins on a day early in December, 2007. Although other people saw him during the following week or so, he soon disappeared.

Every now and then some of our winter residents drop in, too, while looking for a suitable place to establish a winter territory. One day in December 2007 I saw a Northern Shrike perched in a tree along Cassels Street, while on at least two other occasions I’ve heard Snow Buntings flying over. American Tree Sparrows also stop by on their way south, though I don’t think I’ve ever seen a flock overwintering here.


Mud Lake is not renowned for its shorebird migration; you are better off checking the mudflats at Shirley’s Bay or Andrew Haydon Park. However, Spotted Sandpipers can usually be seen along the channel between the ridge and the island all summer long and into the fall; the only other species I’ve seen here was a Solitary Sandpiper on September 2, 2012.

Owls do show up from time to time; I got my lifer Great Horned Owl and Eastern Screech Owl here. Great Horned Owls used to nest here but haven’t in the past few years, while the status of the screech owl is unknown. A Barred Owl also used to reside here, until it was shot by poachers last Thanksgiving.

The most common raptors seen here include Osprey, Sharp-shinned Hawk, Cooper’s Hawk and Merlin, all of which (except the Osprey) can be seen here year round. Peregrine Falcons sometimes hunt here, and are occasionally seen flying along the river searching for prey.


One normally doesn’t expect to find gallinaceous birds at Mud Lake, but in 2006 and again in 2011 I’ve common across single Wild Turkeys within the conservation area. On another occasion I heard something rustling in the leaf litter in the southeastern section of the woods; when I turned around, I was surprised to find a Ruffed Grouse walking along! These birds, as well as the large number of rarities over the years, prove that ANYTHING can turn up at Mud Lake!

Although Mud Lake is worth visiting in any season, it is the one destination every birder MUST visit during migration. Spring and fall are my favourite seasons, chiefly because of the variety of species that can be found and the greater chance of something rare showing up. However, summer is a great time to visit as well, as many other types of wildlife, particularly dragonflies, can be seen. It is the one place that never lets me down, even in the depths of winter when most of our breeding birds have fled, for there is always something interesting to see!

18 thoughts on “My Favourite Places: Mud Lake

  1. Hey Gillian!! I saw that photo of beaver at Mud Lake you took. That photo I took is almost the same at Mud Lake last November 2012. However, I saw a few beavers swimming around and also I saw a brown weasel. Nice shot!!! I met you on the trip to Amherst Island last January 26th. From Eric Staflund

    • Hi Eric – yes, I remember you from the trip!

      Yes, this beaver was photographed in mid-November 2012. There were two of them at the south end of the lake; one was gathering branches while the other was eating. Given that they breed in January/February, perhaps we’ll see a couple more in the spring! I haven’t seen any weasels there in a few years now, though I’m sure they are around. It would be nice to see one again.


  2. Hi Gillian! About a week ago, I walked to Mer Bleu and saw a large brown bird feeder by the parking lot. I was hanging around seeing northern cardinal, blue jays, common redpolls, American tree sparrows hopping around the trees but something surprised me to see on the snowy ground a white ermine hiding in the hole of the snow. It went out looking and eating some seeds. It can run fast through the forest. I took five photographs of that white ermine.

    From Eric Staflund

  3. Fantastic article, I enjoyed reading it, I remember accidently coming across Mud Lake back in the mid 90’s on a bike ride one summer afternoon.

    This place is such a gem hidden within the Ottawa area. I haven’t gone back in well over a decade, but plan to now that I have taken up photography as a hobby.

    One of my memorable moments on my first visit to Mud Lake was this huge bull frog just sitting in the water about a meter from the shore. I swear!! I have never seen a frog as big as this one, and for all I know it could of been a starring at Guinness book record, it was huge.

    Every time I extract this memory, I think of Mud Lake, and how beautiful this place really is.

    • Thanks for commenting, Urban Dweller!

      Mud Lake is a great place for photography, and there are certainly lots of frogs and turtles around the lake and along the river in the summer. I’ve never seen any large bullfrogs there (though I have in other places). I’m just waiting for it to warm up so I can start seeing more reptiles and amphibians and dragonflies!


  4. Thanks for talking about all the seasons! I saw a weasel last winter – are they a common sight? I live in the Merivale area. Very curious and cute little creatures 🙂

    My photos…

    • Hi Jarrett,

      Weasels are probably common in wooded areas adjacent to wetlands, streams and rivers, but they are adept at keeping themselves hidden from human sight. I have only seen them three times at Mud Lake, so they are definitely there; the chances of crossing path with one, however, are very slim.

  5. Nice write-up of one of my favourite places in Ottawa – and I’m not even a dedicated birder! But it is a place in the city where it feels like you are far from the city, so I stop in often as I bike home from work. Back in the 80s it was the also the last local place where you could reliably find ring-necked pheasants, but they are long gone now.

    • Thanks Michael. It really is a terrific spot to get a taste of nature in the middle of the city. I wish I had lived here when the pheasants were still around…would have loved to have seen one walking around Mud Lake!

  6. Thanks for what you do. You do it very well, and it is very interesting to me. I just discovered your website and I plan to do a lot more reading. The main thing to say about myself is that I have lived for 48 years in a house that is a 10 minute walk from Mud Lake. During the pandemic my favourite activity is to walk along the river from Woodroffe Avenue to Mud Lake always with my camera. Now, I have a goal to see more of the birds and other wildlife that you describe. It is so much more than I thought.

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