Sorry, my misreading. If you simply assume your spouse's name, your birth certificate remains unchanged, but if you elect to legally change your name to your spouse's name, in Ontario, your birth certificate does change. Apparently the same is not true in other provinces.

See here.

>I have never heard of any name change actually changing a birth certificate! How do lineages remain accurate and traceable?
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>>To the best of my knowledge, it's perfectly acceptable in Canada. The way the law reads allows a spouse to adopt the name of the other spouse. It doesn't refer to man or woman or hermaphrodite. There are small catches here and there. In many provinces, when you adopt your wife's/husband's name, your birth certificate remains unchanged, so you can use it as ID if you want to use or go back to your original name, but here in Ontario, your birth certificate changes too.
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>>>Our very own Christof Wollenhaupt, nee Christof Lange, did exactly that. When he married he took his wife's family name. It did strike me as odd but my respect for him made me think maybe there's nothing wrong with it. We should probably all open up our thinking from time to time.
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>>>>Now a husband can take the surname of his wife.
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>>>>http://cbs5.com/local/local_story_128002137.html
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>>>>I once met a man whose legal name was “Ocean”. That was it. Extremely intelligent but when he talked to you he had to face you with the front of his body and head 90 degrees from your left side. Perhaps that is what we need – one word names. But then George Lucas had a movie titled THX 1138. That sounds way cool!