As new condos sprout ceaselessly on long-vacant, raggedy, empty plots, the city is losing many of its inadvertent oases of nature.
What many don't realize, however, is that wise use of small spaces can redeem our concrete landscape. Even the smallest morsel of ground, patio or balcony can be transformed into a micro-habitat for an array of untamed but welcome creatures.
For instance, just a smattering of nectar-rich wild bergamot, bee balm, purple coneflowers, black-eyed susans, aster and goldenrod can entice butterflies. To keep the little flutterers around to breed, you also need to offer up the favourite foods of their caterpillar offspring. Orange-and-black-winged American lady butterflies, which migrate here from the southern U.S., seek out the leaves of wildflowers such as pearly everlasting or pussytoes to lay their eggs on.
The caterpillars of great spangled fritillaries feast on violets. Patches of garden left to grow wild attract common sootywings, which deposit their eggs on the common wild plant lamb's quarters.
If you want to lure monarchs, make sure there's milkweed. Carolyn King of the Toronto Entomologists Association says she's seen black-white-and- yellow-striped monarch caterpillars on milkweed growing from cracks between asphalt and a brick wall at Richmond and Spadina.
The research of former Trent University biology student Kristy Hogsden concludes that even small amounts of appropriate habitat in urban neighbourhoods can sustain a wide variety of local butterfly populations. She found 26 species in a number of different locations in Peterborough. She also found that if you mow they won't show.
Simply planting a variety of shrubs and flowers and keeping a tiny pond has enabled bird illustrator David Beadle to record 130 avian species in his 15-foot-square backyard near Bathurst and Dupont over the years. The majority, he says, are migrants eager for a refreshing bath, a bite to eat and some shut-eye in a safe, comfortable spot. "Birds will make use of any available habitat, no matter how small," says Beadle.
Bird-bidding bushes include raspberry, currant, elder and hawthorn. Of course, house sparrows and starlings will flock to any small space, but far more wary species such as grey catbirds, great crested flycatchers, blue-grey gnat-catchers, indigo buntings and rose-breasted grosbeaks need thick tangles of branches and indigenous plants with insects or berries.
According to Paul Prior, a fauna biologist with the Toronto and Region Conservation Authority, naturalized yards and other small spaces should increase the presence of these normally street-shy species.
But even in tiny yards or on decks, vines such as Virginia creeper and ivy can turn walls and fences into nesting sites for birds like cardinals, house finches and wrens.
Naturalists tout almost any kind of water feature, from dripping pipes and hoses to birdbaths and ponds, as a big plus in attracting many different wild creatures. "Birds like running water the most," notes wild garden enthusiast King, whose own backyard evergreens harbour red squirrels, relative rarities in Toronto. "It's really amazing how, if someone makes a pond, dragonflies and damselflies show up."
Backyard ponds also beckon frogs and toads, which, like dragonflies and damselflies, eat mosquitoes and other garden pests. King knows of a green frog - a smaller version of a bullfrog and not generally found in downtowns - showing up in a pond near Mount Pleasant Cemetery, while toads have been heard trilling their spring mating songs as deep in the city as Coxwell and Danforth.
Meanwhile, high above the ground, roofs are also turning green, adding new multi-dimensional opportunities for habitat. Grasses, plants and shrubs planted in lightweight growing mediums over large rooftop surface areas could vastly expand the terrain available for birds, butterflies and other insects and create effective sanctuaries for rare or beleaguered native plants.
"If you look at the valleys and ravines around Toronto, a lot of industrial and commercial areas are situated around them," notes Steven Peck, executive director of Green Roofs for Healthy Cities. "Why not have a special (municipal zoning and incentive) category for green roofs that are within 500 metres of a ravine and use the benefit of those rooftops to extend habitat for species already there.'
Of the almost 100 green roofs already established in the city, one plot in a demo project on top of City Hall has been planted specifically to attract birds and butterflies. A much larger meadow-like expanse above a new computer science building at York University is also being studied for its ability to accommodate insects and birds.
The benefits to wildlife have already been proved in Europe, where about 20 per cent of Germany's buildings have green roofs, says Peck. He'd like to see the entire waterfront development outfitted with green roofs. "There's a huge amount of land area on roofs, something like 27 per cent of this city," he enthuses.