I've heard it used for bird ecology for sure. The 100th meridian is the general cutoff between eastern bird species and western bird species. I think it holds

I've heard it used for bird ecology for sure. The 100th meridian is the general cutoff between eastern bird species and western bird species. I think it holds true in other areas of biology. I've driven back and forth across it a lot. Obviously it's a gradient and not some magic barrier the great-tailed grackles cannot cross. And we do get western kingbirds a couple hundred miles east as well as western meadowlarks. It's still a handy boundary so that you know more or less what to expect in a given area ecologically. https://news.climate.columbia.edu/2018/04/11/the-100th-meridian-where-the-great-plains-used-to-begin-now-moving-east/ https://news.climate.columbia.edu/2018/04/11/the-100th-merid... https://weather.com/science/environment/news/2018-04-12-100th-meridian-great-plains-shifting https://weather.com/science/environment/news/2018-04-12-100t...