This inquisitive and charismatic bird waddled along the sand until standing directly below a group of tourists. Then its yellow irises twinkled with curiosity. The juvenile Nazca booby hardly resembles its parents. When hatched, the chick is a white fuzz ball. By the time it fledges, the belly remains white but the top feathers are brown. When the bird reaches adulthood, its plumage is predominately white with a black band along the wings and tail. By then, the sula granti measures three feet with a wingspan nearly twice as long.