Complex sentence: Several key plumage characteristics separated the heath hens from their Great Plains counterparts: heath hens generally displayed a strong reddish hue in their plumage, especially in their crop area, and much thicker barring throughout the breast and sides.
Split into simpler sentences: Several key plumage characteristics separated the Heath hens from their Great Plains counterparts. Heath hens were generally a strong reddish hue in their plumage, especially in their crop area, and much thicker barring throughout the breast and sides.