Krmiči holubů, nebo šedí panteři?

Naše videa

Za císaře pána

Ako sa varia halušky

Co vidím z okna ložnice

Dolina


Chvilka poezie

  • česky

Lifecycle of Monarch Butterfly

Home » Lifecycle of Monarch Butterfly

These days millions of monarch butterflies (Danaus plexippus) leave 12 fir forest groves in central Mexico for a round trip which leads them to Canada and back in the Fall. They hibernate in the mountains and cover the firs like blankets. In March they first fly to the Gulf Coast where they feed on
milkweed, lay eggs and die.The next generation
makes it in several weeks further North and dies again. The whole round trip is multigenerational and only the grandchildren and great grandchildren make it back to Mexico.

The monarchs return to the same mountain, same grove and to the same tree. Their unique time clock and sense of direction was studied by neurobiologist Dr. Steven Reppert from the University of Massachusetts. They found a timing device in four monarch’s brain cells which undergo rhythmic molecular changes. This clock is driven by two genes. One is sensitive to blue blue light and synchronizes the cells to cycles of light and darkness. The second gene causes rising of specific amount of protein that measures passage of time since it was last activated. This gene was thought to be found only in mammals.

Monarch butterfly weighs about an ounce but can fly at speeds 30 miles an hour, 12,000 feet high and on a distance of 375 miles.

Milan Kaluš – Santa Fe, New Mexico, USA