"Research: Drowzee Biomes (and the curious case of the anti-biome islands)"

#PokemonGO: I live in Ann Arbor, Michigan, where downtown is a strong and well-defined Drowzee biome. I've been digging deep into data I've collected and have noticed some strange findings.Most of town is the usual blend of Pidgey/Weedle/Rattata/etc. Compared to that, the Drowzee biome has relative concentrations of Drowzee (over 40%), Tauros, Jynx, Seel, Shellder, Squirtle, Zubats, Magnemite, Grimer, Gastly, Krabby, Koffing, Horsea, Porygon, Omanyte, and Kabuto. Pidgey, Rattata, and Spearow are strangely absent from the biome spawnpoints, being very common elsewhere.The blend changing is very normal for a biome, but I found something strange: spawnpoint islands within the biome with a different blend: around 34% Pidgey, 32% Rattata, and 15% Spearow - over 80% of the spawns, far higher rates than elsewhere in the city. Here's a map of part of the biome; the yellow dots are the Drowzee biome spawns, and the black dots within the Drowzee zone are these strange islands. I looked at my data for downtown Detroit, and the same pattern appears there. It's almost as if the Pidgeys, Rattatas, and Spearows are being driven away from the Drowzee spawnpoints and into these islands.I'm not sure there's a huge practical application to this knowledge, but this being /r/TheSilphRoad, I'm sure this will be of geeky interest to more than just me. I know Drowzee is a common infestation - if you have them nearby, do they strongly correlate with Jynx/Tauros/Seel/etc like they do here? And do they have this same pattern of anti-biome islands? via /r/TheSilphRoad http://ift.tt/2e88122