Good News

A lot of people look at mustangs and think they're filling the ecological role previously held by native North American horses that died out around 10,000 years ago.

Two problems with that. First - the area where mustangs currently run was very different 10,000 years ago. It wasn't nearly as dry, and different vegetation grew there.

But more importantly, native horses didn't look anything like mustangs. They were smaller and stockier. They'd have looked more like a modern steppe or Przewalski's horses - or, for that matter, more like a donkey - than anything descended from domesticated horses.

Not saying mustangs should be cleared out as an invasive species, but they're not replacing anything.