Churchill, Manitoba is the "Polar Bear Capital of the World", being built in the middle of a polar bear migration route.

Everything I've read tells me the best time to see the bears there is in November. However, what I can't find out is whether or not that's the ONLY time to see them, or whether if I go in late March/early April, if I'll be able to see any then. It's a 36 hour train trip each way from Winnipeg which I'm passing through, so I want to be pretty certain if I go.

Links preferred, but personal experience of seeing them would be handy too.