If you do residency in Canada, pass American specialty board exam & practice in the US -- can you practice in Canada later with no Royal College exam?

Just wondering if this is possible? Do 5 year residency in Canada, immediately go to practice in the US, do American specialty board exam, and practice in the US for a while. Would the American board certification be transferrable to Canada later on or would you need to write the Royal College exam at that point?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Tags: Canada Source Type: forums