Mercator inflates area by sec²(latitude): nothing on the equator, about double at 45°, and more than triple past 55°.
Because Wood Buffalo National Park sits up at 59°N, the map is anything but honest here — it blows the park up to about 3.9× its true area, roughly 286% more than it really covers. That inflation is the whole reason it can look a giant beside Costa Rica, which lies far closer to the equator and is drawn much nearer its real size. Drag it back toward the equator and the bloat drains away.