Complex sentence: When hunting, they are hard, single-minded, and persistent, courageous, spirited, fast, and agile, they are at ease on a rugged terrain, with a superb nose and powerful hunting instinct.
Split into simpler sentences: When hunting, they are hard, single-minded, and persistent. Courageous, spirited, fast, and agile, they are at ease on a rugged terrain, with a superb nose and powerful hunting instinct.