ology logo
card
337

Purple Crows

OLogy Series
animal
card
337

Purple Crows

OLogy Series
animal

Every fall, over one million Purple Crows journey from northern to southern Taiwan. They spend the winter in warm valleys known as "Purple Butterfly Valleys." In the spring, they return north to mate and lay eggs for a new generation. But these butterflies are under threat. In the past 20 years, many of the purple butterfly valleys have disappeared because of human activities. Today, these valleys and the butterflies are protected.

There were once over 30 butterfly valleys in Taiwan. Today, ___ valleys still have large butterfly populations during the winter.

25

15

10

Are you right?

Correct!

Most of these warm valleys are in Maolin, in the foothills of the Dawu Mountains in southern Taiwan. In the winter, these sites are popular destinations for hikers and butterfly watchers.

Taiwan's ________ have been an important part of conservation efforts to protect purple butterfly valleys.

government

local indigenous people

both of these

Are you right?

Correct!

Today, people in Taiwan recognize how important these valleys are to the country's biodiversity, especially its butterfly populations. Local people also benefit from ecotourism in the valleys.

Purple Crow butterflies migrate _____ in the fall and _____ in the spring.

east / west

north / south

south / north

Are you right?

Correct!

In the fall, these butterflies travel southward to winter in warm valleys. Next spring, they return north to their breeding grounds where they mate and lay eggs. Their winter sites are often called "Purple Butterfly Valleys."

Every spring in mid-April, Taiwan closes sections of a highway to give the Purple Crow butterflies safe passage to the north.

Fact
or
Fiction
?

Fact

The highway cuts across the butterflies' migration route. In the past, heavy traffic killed many of the butterflies. Now butterflies can fly safely across.

Many butterfly species, including the Purple Crows of Taiwan, migrate long distances.

Fact
or
Fiction
?

Fiction

Only one other butterfly species migrates this far. In North America, monarchs migrate south from Canada to winter in Mexico. In fact, these monarchs migrate even farther!

The wings of the Purple Crow butterfly seem to change color as they fly.

Fact
or
Fiction
?

Fact

Their wings glisten blue and purple, but seem to change at different angles of sunlight. Millions of these butterflies were once collected every year for handicrafts.

Purple Crows are actually a group of butterflies in the genus Euploea. There are four Purple Crow butterfly species in Taiwan.

Fact
or
Fiction
?

Fact

They include: Double-Banded Crow (Euploea sylvester), Dwarf Crow (Euploea tulliolus), Striped Blue Crow (Euploea mulciber), and Purple Milkweed Crow (Euploea eunice).

Scientific Name: genus Euploea
Status: common
Range: all around the island of Taiwan
Habitat: a wide range of habitats
Appearance: iridescent blue and purple wings
Cool Fact: Purple Crow larvae (caterpillars) eat the leaves of poisonous plants. The poison is stored in the adult's body, so they taste bad to predators!

Image credits: © National Museum of Natural Science Taiwan.