This article is actually about pigeons which are a naturalized species BUT it demonstrates how geographical habitats can make two different populations separated by as little as 50 miles! Soooo interesting!
Article on first link and study on second:
https://www.nytimes.com/2020/04/23/scie ... -york.html
https://onlinelibrary.wiley.com/doi/ful ... /eva.12972