This Northern Harrier was hunting over a grassy marsh, its head down, eyes watching for rodent prey. You can see the facial ruff, similar to that of Short-eared Owls, another grassland hunter. The ruff helps direct sound to the birds ears. The bird is supremely equipped for visual hunting, eyes far better than ours, and with the ability to see in the ultraviolet light range. This helps because the urine of mice and voles reflects UV light. Tiny squirts of urine, left by the small mammals as scent trails, are homing marks for the hunter. The harrier was seen at Crex Meadows near Grantsburg, Wis., while looking for Sandhill Cranes. The two species share habitat.