Early flyers: Two monarchs in Mexico, in February 2009, fuel up for the long journey north. (Marco Ugarte/Associated Press)

The robins arrived early this year, part of a "big push" north into Canada in early March, according to one birding site.

Ruby-throated hummingbirds have been spotted as far north as Whitecourt, Alta. And pods of massive grey whales have lumbered 8,000 kilometres or more up the Pacific Coast for their annual five-month feast in Canada's Arctic.

But where are the monarchs?

For the second year in a row, the insect world's most inveterate travellers have failed to show up here on time (mid-June) or in the kinds of numbers that butterfly lovers feel are necessary to ensure the creature's already fragile existence.

World's greatest migrators

Sooty shearwaters: 64,000 km round-trip from New Zealand to California and Japanese coasts.

Arctic terns: 34,000 km, Arctic to Antarctic, but no one sure if same year.

Grey whales: 16,000-22,000 km, round trip from Mexico's Baja Peninsula to Arctic.

Indian dragonflies: 14,000-18,000 km, round trip from India to southern Africa.

Monarch butterflies:  4,000 or so km, round trip from Mexico to central Canada.

Ruby-throated hummingbirds: 6,400 km, round trip from Central America to north-central Canada.

Caribou: 6,400 km, longest overland migration, across the Arctic tundra.

Equally troubling, albeit from a PR point of view, the doughty monarch may be in danger of losing its title as the world's greatest migrating insect. A British biologist says he has documented a handful of Indian dragonflies  that can travel up to 18,000 kilometres round trip, from India to southern Africa and back, with stops in the Maldives.

Biologist Charles Anderson's assertions about India's peripatetic pale-spotted emperors, twisters and blue-perchers have not yet been widely documented, which is not something you can say about monarchs.

Lovingly monitored

The monarchs' unique, 4,000-kilometre journey in the eastern portion of North America — from their wintering grounds in a particular Mexican forest to summers around the Great Lakes (and as far north as Hudson Bay in some years) — is intensely tracked.

First sightings and larvae are tallied by enthusiasts at over 1,100 official monarch way stations in the United States and Canada, as well as by countless tagging groups, school children and backyard spotters who report their findings to websites such as Journey North and Monarch Watch. This year, they're reporting the same phenomenon: "This is not butterfly weather!"

After a great winter, nearly five hectares worth of monarchs — tens of millions of them — billowed out of Mexico in a huge cloud headed for their first frenzied mating session in the southern U.S.


Monarch butterflies hang from a tree branch at a reserve near the town of Chincua, Mexico, in February 2009, just before their journey north. (Marco Ugarte/Associated Press)

But Texas was not a good first stop: Near-drought conditions made it too dry for the milkweed, the poisonous plant that is the monarchs' only food. And South Carolina was a bust as well.

Still, by late May, monarch sightings were at some of the highest they've been in years across the mid-American states (Ohio is reportedly having a good butterfly year). Butterfly blogs were crowing about an early arrival of at least some monarchs in southern Ontario and Nova Scotia's Annapolis Valley.

Then they ran into June and July.

'Quite concerned'

The unseasonably cold and torrentially wet weather looks to have halted the journey north and probably drowned millions of the orange-winged migrator. At the very least, it is being blamed for creating the ideal conditions for the fungi and other pathogens that feed on monarch larvae.

"I'm quite concerned," says Don Davis, the Canadian representative on a Canada-U.S.-Mexico monarch monitoring group. "The reports of sightings are considerably reduced all over. Even Quebec is asking: Where are the monarchs?"

It hasn't been a great summer for most butterfly species, Davis says. "You are hardly seeing any red admirals" either.

The mighty monarchs have survived adversity before, notably in fall 2005, when they flew south in the teeth of Hurricane Katrina and its sister storms.

But the generation that summers in Canada and in the most northerly U.S. states (such as Ohio) is a special one.

It is the group that, born at northern latitudes, fattens up on Canada's unwanted milkweed and forgoes mating altogether in order to somehow fly the entire distance back to that specific wintering ground in central Mexico, a place this particular generation has never before seen in its short but well-travelled life.


Monarch migration calendar (Parks Canada/Point Pelee National Park)