Nature

The Monarch butterfly is scientifically called the Danaus plexippus. The monarch feed on milkweeds thereby making them poisonous and hence also called milkweed butterfly. The monarch butterfly is most commonly seen in North America. The life span of a monarch butterfly is between six and eight weeks. The metamorphosis of the monarch butterfly includes the egg stage, the caterpillar stage, the chrysalis stage and the mature butterfly. Their respective life spans are four days, two weeks, ten days and 2-6 weeks.

One major characteristic of the monarch butterfly is their migrating capacity. They travel a very long distance between 1200 and 2800 miles for this purpose. They can travel at a maximum speed of 80 miles an hour. This is the only butterfly that can fly both north and south. The monarch butterfly travel from their North American habitats to Mexico as the winter is less severe and extends their life span to a maximum of five months. This mostly happens in the months of February and March. Once the monarchs come out of hibernation, they move north breeding along the way.

The first generation monarchs live through March and April, the second generation through May and June and the third generation through July and August. The months of September and October gives rise to the fourth generation monarch that fly southwards to Mexico for their hibernation and an enhanced life span. In short, the generation of monarch that head for hibernation are the great-great-grandchildren of the monarch generation previously migrated to Mexico.

The levels of Juvenile Hormone (JH) in the monarch butterflies indicate their life span and their ability to stop laying eggs. The duration of their journey exceeds the average life span of the monarch butterflies. The butterflies that spend their winters in Mexico are more reproductively active than the fall butterflies. The reduction in the JH level increases their ability to live longer and abstain from actively reproducing and laying eggs. The reproduction period for these hibernating butterflies starts in spring when they prepare themselves to return to their Northern habitats. This is the reason why the overwintering butterflies do not lay eggs in Mexico.

Monarchs are not warm-blooded insects. Low temperatures could freeze their body tissues literally breaking them from the inside. This is the reason for their migration south during winters. The monarchs migration can be equaled to that of birds that fly south for overwintering. The trans-volcanic range mountains of Mexico are a favored location of these monarchs. The monarch butterfly roosts are located 60 miles west of Mexico City.

As the monarch butterflies travel on their own it is believed that they are guided by the suns orbit during their journey. The butterflies feed themselves on nectar to supplement their energy. The problems that are faced by these migrating insects include fatal illness, winter storms and other predators.