In defense of wildlife biologists, they are waiting for all the facts to come in. Science is by nature rather conservative. Now, if you have ten years in a row where the rut kicks off earlier, then I'm reasonably sure the biologists will get on board. Remember that something like the observations of a single hunter are highly subjective, and prone to wild swings in results due to just random chance.

That said, one scientific rationale that might be advanced is that strong, healthy animals are documented to breed earlier than weaker specimens. If those Canadian winters are getting milder, that would lead to healthier critters since northern winters can be so brutal. A growing herd is probably a healthy herd, so it all fits. However, I'd still be very cautious about selling out to a conclusion on only two years of anecdotal information. In other words, I wouldn't change my hunting plans for the year to come just yet. Just my opinion.