You're right, that's my bad for confusing migratory bird with big game.
There are however rules about 5 round magazines for semi-auto rifles in the Alberta Hunting regs and many US states. That might not mean much for someone using an XCR-M in .308, but it could mean a hell of a lot for someone using a Kriss Super V in .45
"It is unlawful to: set out, use or employ any of the following items for the purpose of hunting big game:
ammunition of less than .23 calibre,
ammunition that contains non-expanding bullets,
an auto-loading firearm that has the capacity to hold more than 5 cartridges in the magazine,
a shotgun having a gauge of .410 or less,"