Northern Prairie Wildlife Research Center
The Bulwer's petrel is the smallest of the group. They are sooty-brown birds with lighter bars on the upper wing, a short wedge-shaped tail, and black legs and feet. Sixty to 70 pairs of this small seabird nest in the rocky crevices of the causeway on Sand Island. The oldest known Bulwer's petrel, banded 22 years ago, was discovered there in 1993.