One evening, I think I witnessed two butterflies in a courtship ritual. They were striped with long tails and antennae. The butterflies faced each other and trembled as they took turns displaying themselves. The performance went on for 20 minutes. Can you explain their unusual behavior?
—Nicles Leary, Live Oak, Florida
Tom: The butterflies were likely a male and female zebra swallowtail, and they were—as you guessed—performing a courtship ritual. Sometimes males will fly around the female to coax her into mating, especially if she is newly emerged and has not mated previously. Courtship rituals are common among butterflies, and most females breed soon after they emerge from the chrysalis and before they start to fly around. The female attracts the males by emitting pheromones, which are carried by air currents. Males quickly arrive and often compete for the affection of the female. They frequently go through impressive aerial flights themselves—chasing one another.