Critter Corner - Monarch Butterfly

DID YOU KNOW:

Monarchs migrate (relocate) each year in enormous numbers from summer breeding grounds in Canada and the eastern United States to California and Mexico.  This amazing migration takes several generations of monarchs to complete.  Each monarch migrates in only one direction during its lifetime.

EATING HABITS:

Monarchs feast on one type of plant -- milkweed -- but there are more than 2,000 varieties of milkweed.  As a caterpillar, the monarch has jaws that it uses to gorge itself on the plant when it hatches from the egg.  As a butterfly, the monarch feeds on the flower's nectar using a hollow feeding tube, or proboscis, which is rolled up when the insect isn't eating.

THE YOUNG:

Mother monarch lays several eggs under a milkweed leaf.  A caterpillar (larval stage) emerges in a few days and begins eating.  The caterpillar sheds its skin several times during a few weeks.  Then it spins a button of silk and hangs from the silk.  The caterpillar spins another silk thread that holds its body to the leaf.  Under the caterpillar's skin the chrysalis forms and the skin falls away.  It is in the chrysalis (pupa stage) that the butterfly forms.  The chrysalis cracks open and the butterfly emerges.  The new monarch waits for its wings to dry and harden before it can fly.  It takes about a month for a monarch to go from egg to adult butterfly.

HABITAT (HOME):

Monarchs are found in North America and around the world between 45 degrees north and 45 degrees south of the equator.  They depend on the milkweed plant for their life cycle.  Only North American populations migrate!

DEFENSIVE HABITS:

A monarch's only form of defense is a mild toxin (poison) that causes it to taste bad to predators.  The toxin is from the milkweed plant.  The monarch's bright colors help warn predators of the bad tasting snack.

 

UNUSUAL FACTS:

  • Caterpillars don't have lungs; instead they breathe through holes on their sides called spiracles.

  • The bright patters on butterflies are made by thousands of scales that cover their wings

  • The scales are not like those of reptiles.  They are modified hairs.

 

(Photo credits: Large photo, US Fish and Wildlife Service: Milkweed, Wisconsin Department of Natural Resources: Caterpillar, Environment Protection Agency; Butterfly on pink milkweed, US Fish and Wildlife Service; Butterfly on purple milkweed, Missouri Department of Conservation)