Swallowtail Butterfly Facts

These butterflies have boldly patterned wings with dark lace-work. These wings are designed not only to confuse predators but to attract a mate.

Facts about the Swallowtail Butterfly

1. The short ‘tails’ on the hind-wings is where this beautiful butterfly takes its name.
2. Males and females often have completely different wing colors and patterns.
3. There are over 500 species of Swallowtail butterfly worldwide.
4. The caterpillar exudes unpleasant chemicals from a forked gland to protect itself.
5. Wingspan: 4.4 – 20 cm
6. Caterpillar length: 6 – 7 cm
7. Number of eggs: 100 – 200
8. Caterpillar stage: Approx 30 days
9. Lifespan: A few weeks as an adult
10. Adult butterflies can feed on the sugary flower nectar which it sips by extending its long, curled tongue into flowers. Each of its eyes consists of hundreds of facets, each with a tiny lens. The compound eye cannot create a single, focused image, but it can detect movement from any angle.
11. The chrysalis is spun by the caterpillar itself before sealing itself inside. The chrysalis can seal so much that it can even survive underwater.
12. When at rest, the butterfly holds its wings together. It opens them at brief intervals as to reveal a brightly-coloured spot on each hind-wing; these spots, to predators, look like the eyes of a much larger animal, hence protecting the butterfly.
13. Since the lifespan of the swallowtail butterfly is fairly short, the adult male tries to find a mate a quickly as possible. When he succeeds, the pair begin to court briefly, fluttering around each other, before mating. Mating can take up to 45 minutes while the male fertilizes the eggs of the female.
14. Not much sooner after, the female lays her eggs. 10 days later, the eggs hatch into caterpillars, which feed rapidly. Baby caterpillars moult their skins five times before reaching full size which takes about a month.
15. The caterpillars usually eat their empty egg-shell, then they devour the leaves of fennel or milk parsley for several weeks before changing into a pupa.
16. Swallowtail butterflies continue to flutter their wings even after landing on a stem to feed. This hovering helps to support its weight on fragile, delicate flowers.
17. On a conservation note: many species of swallowtail butterfly are widespread, but numbers of some have declined steeply, such as the British swallowtail subspecies Papilio Machaon Britannicus. Found only in the fens of Norfolk, its population has been greatly reduced by the drainage of its habitual wetlands for farming, although it is now protected by law.
18. Because of their large wingspan, the swallowtail butterfly can fly very fast. Even so, compared to other butterflies, they flap their wings very slowly.
19. Swallowtail caterpillars of some species are completely immune to poisons and toxins from plant matter.
20. The swallowtail’s sense of taste is located at the ends of its legs, where tiny organs recognize sweet substances.