Year after year, a tiny bird known as a warbling vireo makes an epic journey from South America all the way to the north shore of Lake Ontario, where it takes up residence on Toronto's Leslie Street Spit in the virtually the same shrub.

The little songbird, weighing no more than a 25-cent coin and affectionately nicknamed 'Warble' by staff at the Toronto Conservation Authority, is just one of millions of birds that visit the downtown peninsula known as Tommy Thompson Park during the spring migration.

Some, like Warble, complete their journey at the park, while others stop to rest, refuel, or wait out bad weather before continuing north to nesting grounds in Canada's boreal forest and even the Arctic.

Toronto and Hamilton serve as strategically-located layover points on the "songbird superhighway" that the migrating birds follow.

Toronto park a 'gas station' for migratory birds

"Toronto is really quite often the gas station for birds on their northern migration," said Ralph Toninger, chief of Toronto Conservation's habitat restoration efforts and manager of Tommy Thompson Park.

"Specifically, that's why Tommy Thompson is a key area and one of the very important and frequented stopover locations on the spring migration."

There are a number of factors that make "TTP" a prime location for both birds and bird watchers. Its position as the first dry land makes it a major magnet for exhausted birds seeking a place to rest their wings.

And the Lake Ontario weather effect means trees often haven't completely "budded" by the time the migration is in full swing, making birds easier to spot.

"You see so many birds, and it's strange in a city environment, but you see more birds than in a lot of shoreline areas to the east and west of us," Toninger said.

Weather can also play a major role, with migratory birds often using TTP as a staging ground to wait out storms.

"Birds will move en masse during prime conditions and if they hit a front or bad weather it causes these fallouts, and when you get successive poor weather days it just builds and builds," Toninger said. "Then, once nightfall hits on a clear night, they just pick up and head north again."

It's the main attraction at the Tommy Thompson Park Spring Bird Festival.

Warblers are the main attraction. They are tiny, colourful, insect-eating birds moving north from their winter nesting grounds in Central and South America to feed on Ontario mosquitoes.

The brilliant yellow warbler, often mistaken for a canary due to its colour, makes for a "guaranteed" sighting these days at the park. And last week, for only the second time ever, birders spotted a rare worm-eating warbler.

Black-throated blue warblers are also around, along with black-throated green warblers and the far-flying blackpoll warbler, which migrates from the southern tip of South America all the way to Ontario.

"In a lot of cases it's the only time people will have a chance to see a bird like that, and to hear it sing, because it breeds in areas where people simply do not live," Toninger said.

Tommy Thompson Park bird research station

Researchers at TTP capture and band birds that pass through as a means of tracking both local and global migratory patterns and populations. Through banding they’ve discovered that some birds, like 'Warble,' come back year after year.

Over the course of roughly a decade, a yellow warbler banded with the number 22105811 was caught 21 times -- about twice a year – and became a much anticipated visitor to the park.

"He migrated back and forth from Latin America to TTP at least 10 times, and if you pile all that together that's 30,000 kilometres of flight from a little creature that weighs about the same as a quarter," Toninger said.

"It's blown us away. The assumption was these sorts of birds don't live that long, maybe a couple of years and then they're food for other birds. But this guy made that flight every year for a decade."

In addition to the songbirds, migratory owls pass through the park (for some northern owls Toronto is their southern migratory destination), including snowy and saw-whet owls, great-horned, long-eared and short-eared owls.

In recent days, Arctic shore birds have been moving through the area, including the avocet, with its long, upturned bill, migratory loons and sandhill cranes. And a massive colony of 30,000 cormorants is hard to miss, as the dark-coloured, fish-eating birds hold court on one arm of the spit.

Hamilton habitat restoration pays dividends

In Hamilton, years of habitat restoration efforts by the Royal Botanical Gardens and the Hamilton Conservation Authority appear to be paying off.

Hundreds of square kilometres of green space, parks and conservation areas have made the region a hotspot for the birding community.

Whether they're coming to spot the newly-hatched eaglets in Cootes Paradise marsh (the first in over half a century to hatch on the north shore of Lake Ontario), watching migratory raptors from the viewing platform near Grimsby or spotting migratory birds as they pass through Fifty Point Conservation Area -- the area attracts birders from all over the province.

And like the Leslie Street Spit, the Hamilton area is well known for its songbirds, especially during the spring migration, said Bruce Mackenzie, a longtime birder, past president of the Hamilton Naturalists Club and director of customer service at the Hamilton Conservation Authority.

In recent weeks birders have spotted an eared grebe -- a water bird typically only spotted in the Prairies -- and a rare white-eyed vireo. Horned grebes are also flitting through the area along with tens of thousands of warblers, Mackenzie said.

"Hamilton, because of our geographical location and our natural areas, we just have so many areas that are available to everybody for observing bird migration and we get some things no other community gets -- the spring hawk migration, the water bird migration on the shore of Lake Ontario. Red-throated loons are going through right now!" Mackenzie said.

Hawk Watch

At nearby Beamer Memorial Conservation Area, just outside Grimsby, a dedicated group of bird watchers gather each day during the spring migration to track the raptors that ride warm updraft currents up and over the escarpment.

Hundreds of birds pass over each day -- sometimes "kettling" in massive groups ranging into the thousands that include everything from red-tailed hawks, cooper's hawks and rough-legged hawks, to turkey vultures and falcons.

Volunteer enthusiasts like Frank and Sandra Horvath climb the Niagara Escarpment Hawk Watch's elevated platform at least once a week, and spend eight hours identifying, tracking and recording the birds that glide effortlessly overhead -- sometimes little more than a distant dot in the sky.

Longtime birders, they have travelled all over in pursuit of their hobby. But like the migratory birds they have become obsessed with, they always return home to the Hamilton area for the spring migration.

"They're amazing -- to fly so far, to know where they've been, where they're going. Some fly from South Africa all the way to the Arctic -- it's just amazing," Frank said, putting his binoculars down for a moment as yet another massive raptor passed overhead.

"For birders the world comes alive. Once you start looking for birds you start to notice other things as well. The challenge goes on for a lifetime."