Identification
Scientific Name:
Danaus plexippus
Common Names:
Monarch, King Billy, palomas de los Santos

Classification
Class: Insecta
Order: Lˇpidoptera
Family: Danaidae
Genus: Danaus
Species: plexippus
 

In Canada, some people refer to the Monarch as the " King Billy " due to its brilliantly patterned black and orange wings reminiscent of the colours of the coat of arms of William of Orange, who became King William III of England.
  

Habitat
A tropical butterfly native of Mexico, the monarch extended its range northwards some 20 000 years ago. Most monarchs spend the summer months in southern Canada and the northern United States. Over the last century, the species has extended its range to include the Hawaiian Islands, the Marquezas, New Caledonia and east coast of Australia, and New Zealand.

Profile
Some aspects of monarch migration remain a mystery to this day. Barely emerged from their cocoons in late summer, they set out -- with disconcerting assurance --, for the fir forests of Sierra Transvolcanica, a few hundred kilometres from Mexico City.
 
On their migrations, that can be some 3 500 km long, the monarchs stop at the same spots, even the same trees, as their ancestors . . . places they have never seen before!
 
No monarch ever completes two migrations, or even a two-way migration. The young butterflies that migrate to Mexico in early fall live through to February or March after producing their offspring who assume the responsibility of making the journey north where they will reproduce and die.
 
Monarch caterpillars feed almost exclusively on milkweed leaves, The sap of the milkweed contains a chemical which makes monarchs unpalatable and thus enables them to avoid predation.
 
These marathon travellers have but one regret: they're not eligible for any frequent flyer program!

In Sierra Transvolcanica, there are as many as 10 million monarchs per hectare of forest. Fortunately, everyone keeps pretty much to himself during the five months of wintering. Wings folded, the butterflies remain fairly motionless, suspended from the same branch until spring.
  

When it hovers, beating its wings, a monarch burns 140 mg of fat in 11 hours, but in gliding flight, it has enough stamina to fly 44 hours straight.
  

Birds attempting to eat a monarch soon spit the butterfly out, and are left with nothing but a bad memory . . . one they never forget -- which is good news to all monarchs.