“Airplanes have been changing the flight routes of where birds fly …” said Lisa Gautier, president and founder of the nonprofit Matter of Trust. “We’ve been vacuuming up all of our own hair and our pet fur. We’ve been corralling animals in with fences. We’ve been changing the migration routes of animals with our roads. And so, quietly over the last couple 100 years, we’ve been changing how much animal fiber hits the ground, and nobody thinks about it.”