Complex sentence: In almost every study in the contiguous western United States, leporids dominated the diet; 12 out of 16 dietary studies in North America showed leporids as the most common prey group, in some areas comprising over 75% of prey remains.
Split into simpler sentences: In almost every study in the contiguous western United States, leporids dominated the diet. Twelve out of sixteen dietary studies in North America showed leporids as the most common prey group, in some areas comprising over 75% of prey remains.