"Where did the Swinubs go? A hypothesis on "seasonal" Pokemon"

#PokemonGO: I live in the Boston area (Cambridge, to be precise), and since Gen 2 came out, Swinubs were everywhere. They were pretty much the new Rattata, and I completed my ice badge within a few days of release.However, I recently noticed that they've all-but disappeared. I don't recall seeing any since the water event started, and they haven't returned since it ended.My hypotheses are that either:Swinubs were a seasonal Pokemon for the winter in Boston, which is now officially over. While they'll still appear, their spawn rate has been significantly decreased.Alongside the water event, Niantic performed a significant qualitative shift in the spawns, and the fact that it's near the start of spring is purely coincidental.What do you think? Have you seen a similar decrease in Swinub in your region, or a general change in the local common spawns? via /r/TheSilphRoad http://ift.tt/2nA4q24