URBANA, Ill. – The prairies of North America once covered vast stretches of land, with towering grasses creating ideal nesting and forage habitat for grassland birds. But the deep, rich soil and treeless expanse also represented the ideal conditions for farming – both row crops and cattle grazing – in the eyes of settlers. Today, largely thanks to agricultural conversion, a mere 1 percent of tallgrass prairie remains. And what’s left is now being threatened by invasive species and forest encroachment.