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Eastern Tiger Swallowtail Butterfly

Scientific name: Papilio glaucus

The eastern swallowtail caterpillar has false eyespots to confuse birds and protect it from predators!

Native to eastern North America, it is very commonly seen in our gardens, especially if you have milkweed, plants in the aster family or joe-pye. But these butterflies are not too fussy which is why their numbers are secure. Unlike the monarch which just has one host plant (the milkweed), eastern swallowtail caterpillars can eat the leaves of many different types of trees and plants including the black cherry tree, the ash, lilac, tulip tree, and willow.

This photograph below is of a female. She has an attractive line of chevrons along her hind wings which are washed in a vibrant blue. The male lacks the blue coloration. Here is one instance where the female is more glamorous than her male counterpart.

Male Eastern Tiger Swallowtail on purple verbena
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The adult butterflies like to nectar on red and pink flowers in particular.


They thrive in a variety of habitats including woodlands, fields, rivers, gardens, parks and roadsides.

Life Cycle

In New York they will usually breed two times in a season. Eggs are laid on one of the host plants. It hatches as a caterpillar where it goes through  five different stages of growth and development and has a unique appearance at each. The caterpillar will create a chrysalis and will pupate for days or even months!


They do not migrate, but overwinter as a pupa in a chrysalis.

Survival Strategies

The caterpillar stage is a dangerous one as they are a sought-after food source for birds, who are feeding their young. Other insects will eat them as well.

The plan? Each stage of the caterpillar has its own disguise or deception. At first, it looks like a bird dropping. Later it develops eyes which makes it look bigger. Later the chrysalis is brown and nondescript.

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