CHURCHILL, Man. — There are likely not a lot of children anywhere in Canada begging their parents to dress up like polar bears or seals this Halloween.

But costume selection takes on unique significance in this northern Manitoba town, where the predator and prey disguises are definite no-nos in the midst of the Western Hudson Bay polar bear population's annual migration to the ice.

"Bears' natural source of food on the pack ice is seals," said Richard Romaniuk, district supervisor for Manitoba Conservation.

"To be honest with you, I've never seen a kid dressed up as a seal - but the message would be don't dress up as a polar bear or a seal," he added with a laugh.

Nonetheless, the very real threat of the mammoth creatures stumbling upon young trick-or-treaters as they go door-to-door means Manitoba Conservation is once again gearing up for its annual Halloween Polar Alert.

The special patrol, carried out for more than 20 years with help from RCMP, Parks Canada, local ambulance and fire officials and the Canadian Rangers, includes a strategic perimeter around the town of 1,000.

About a dozen fire trucks, ambulances and other vehicles either park with their engines idling and spotlights shining or cruise the streets to give children about an eight-hour window to satisfy their sweet tooth.

Another crew armed with immobilizing darts circles the community in a helicopter donated by a local tour company.

"It's a bit of an undertaking," admitted Romaniuk. "Basically what we're trying to do is create enough vehicular traffic and activity on the outskirts of town that it discourages the bears from coming into town."

Bears are reported in the community from early summer to the end of November, depending on ice conditions, because of the town's proximity to the world's largest denning area.

Keeping them out of town is serious business. The last deadly attack was in 1983 when a resident who scavenged packages of ground beef from a burned out hotel ran into a bear in a dark alley.

That incident has been a fixture in the back of Dany Allard's mind ever since she moved to Churchill to work at the town office just a few weeks before the attack.

Now the mother of a 12-year-old boy, Allard said she's grateful the Halloween bear patrol allows her son to celebrate the same way kids do elsewhere in Canada.

"It's actually one of the safest nights in town for kids," said Allard.

"If there wasn't this patrol I'd probably just take him in the truck and only let him do a couple of streets."

For those animals not easily deterred by trucks and lights, conservation officers use firecracker shells throughout bear season that set off loud, high-pitched screams and whistles.

Last resorts include rubber slugs and the immobilizing darts.

Those repeat-offender bears who can't stay away day after day are corralled into a bear jail of sorts, a holding compound with 23 individual cells.

The bears are usually kept about a month, which conservation experts believe is enough time to isolate them and break them of their pattern of wandering into town.

Romaniuk said 176 bears were caught last year, with 151 flown out by helicopter because the compound was full.