A regular comeback of the migratory monarch

• flymeto
• Oct 16, 2018

The migratory monarch butterfly has its return perfectly timed. It arrives in Mexico around 1 and 2 November each year. The sky turns black and the clouds of butterflies cover the sun. Their entry into the scene will be enhanced by an equally impressive audio accompaniment. It sounds like a thickened, deafening rain. And so it looks - the fluttering flight of black-orange wings reminds as if the wind was driving a storm of autumn leaves. But he hates trees. These vivid leaves come from distant lands to sit on the branches of mountain firs and wrap them in rich clusters. This is how the monarchs spend the winter.

The souls of the ancestors arrive at All Souls' Day

At the Día de los Muertos celebrations, you can meet the monarch-dressed costumers in the streets. Because butterflies appear in Mexico on the Day of the Dead, he is inextricably linked to him. For the indigenous tribes they represented the souls of the dead, who come to visit them once a year. Children in villages welcome their loved ones with water, because after a long journey from the One World they must be tired and thirsty. The myth of souls returning in butterflies has taken over from the Aztecs. As a result, we know that the traditional pilgrimage of butterflies has lasted for centuries. Only recently have scientists figured out where, how and why they set out for it.

Butterfly destined for great deeds

In 1976, the story behind the annual trip was uncovered. It includes four or five generations of butterflies and 7000 kilometers of flight from Canada and the northern US to Mexico and back. The usual life span of a monarch is 4-5 weeks, but every autumn generation is exceptionally long-lived. He lives about 6 times longer. Given his important mission, he gets up to seven months of life - during which he takes a challenging journey that does just over 4000 kilometers (compare with 4000 kilometers of freedom along Route 66 ). For a long journey, however, does not have a lifetime, but about two months. Thanks to rising air currents it can fly up to 100 km a day. Other butterfly species can only dream of it in comfortable hoods. But the task of the chosen generation does not end there. On the list is still hibernation in Mexico, mating and returning back to the US to bring the world to young.

Trees sagging under the weight of butterflies

For many years, butterflies were supposed to fly to warm regions. That meant the tropics. Although Mexico lies in the right climate zone, but the monarchs' wintering grounds are found in fir forests high in the mountains around 3000 meters above sea level. Temperatures drop to zero in winter. Butterflies use the rule that the number is strength. And the heat. They wrap trees in tightly bunched grapes, warm each other and wait for spring. There are so many sitting on the so-called golden tree that often under their weight the branch breaks or sags and the whole bunch of butterflies ejects. Winter outside the colony is relentless. Literal renegades literally freeze. The survivors will be awakened by the spring sun. The diapause, ie the suspension of reproductive development, ends. Butterflies have a few days to mate, get the partner in addition to genetic material and nutrients and hooray for the last job. They fly ridiculous 500 kilometers into the Arizona prairie and lay eggs.

Under the cleavage is a buried dog

Not just so easy. Eggs belong only and only to the leaves of the cliches - tuber, silk, etc. Hatched caterpillars eat them. However, they are the only ones, because the clergy is poisonous to the rest of the world. Thanks to its essential oils, this property is also taken up by boarders and none of the predators in return eat it. When they graze sufficiently, the caterpillars roll and after a few days they see the second generation of butterflies. You could say that the clergy is the alpha and omega of the entire cycle. Monarchs do not feed on anything else - caterpillars graze leaves, butterflies mow nectar from flowers. The second generation of monarchs already has a normal life cycle and heads further north, where more sneezes grow with the advancing heat. As the butterflies pull, it generates the next generation. Once the flowers run out at the end of the summer, it is time to put the super generation back on.

Abroad for the first time and without navigation

Although they are great-great-grandmothers of butterflies who have wintered in Mexico and have never made a long journey themselves, the monarchs know exactly where and how to fly. As far as possible, it is still an object of conjecture and dispute. One of the theories asserts that in time and landscape theories are proficient in the sun. Massachusetts neurobiologist theory, in which Czech entomologist Ivo Šauman also participated, says that butterflies use photoreceptors and the Earth’s magnetic field to determine the right direction. Another theory states that they have coded landmarks in DNA. The wall, which US President Trump wants to build on the 3000 km long border with Mexico, could say threatened migration. Compared to recent years, the population of monarchs has declined markedly. Therefore, it cannot need other obstacles on its way.

Attention, butterflies

Among those they face today are, besides climate change and tougher winters, illegal logging in the Mexican mountains, and herbicides, by which American farmers spray vegetables and kill kliich, a key plant for the monarch’s life. That is why the area where butterflies hibernate has been declared a biosphere reserve since 2008 and protected by UNESCO. The reserve is about 100 km from Mexico City on the border of Michoacán and Méxica in the provinces of Zitácuaro and Ocampo. There are strict rules. You must not step on butterflies, which is a difficult task when covering the ground as a carpet, so it is also forbidden to descend from the marked hiking trails. You must not start a fire, smoke or even scream. Sleeping butterflies would wake up with noise and would say they would fall on the ground like pears.