Question: how do you tell the difference between a male and female orca whale?
Answer: Adult males, called bulls, have dorsal fins about 6 feet high and triangular in shape, but the dorsal fins of females are only half as tall and more sickle-shaped than triangular. Since it takes up to 20 years for the dorsal fin of males to "sprout" to full size, a young male can be mistaken for an adult female.