Animal populations fall in major cities as they are built. I’m kinda shocked it wasn’t a bigger drop. I leave my pastures I alone most of the year and just mow paths. Most of the year I only see a few of birds other than eagles, hawks, and the like, but in the winter smaller birds flock to the feeders and I get hundreds. Most people can’t not use the land they own. I’m not sure what the answer is for cities. Pesticide use probably isn’t helping. In the agricultural areas I think that is much more important in the US. https://ocm.auburn.edu/newsroom/news_articles/2020/10/141359-miao-bird-study.php#:~:text=When%20birds%20eat%20the%20pesticide,decrease%20birds'%20abilities%20to%20reproduce.