Annual Monarch Butterfly Migration in Mexico

The forests of Mexico come alive every year as hundreds of millions of monarch butterflies fly form Canada and America to go to there to hibernate for four months during the winter.

They return to Canada and America in what can be over a 3000 mile journey each way. The migration is one of the most beautiful natural sights in the world and one of the most fascinating.

The journey takes months to complete on the butterflies don’t live that long so the complete the journey by breeding along the way, and then the next generation continues the trip.

The is fascinating because none of the butterflies have been to their final destination, yet they all know where to go. The number of butterflies that have been making this remarkable trip have been on the decline each year, which is threatening this magnificent sight.

When the butterflies stop to breed, the lay eggs which turn into caterpillars. The caterpillars survive by consuming milkweed and milkweed is being destroyed at an alarming rate b pesticides used to protect GMO crops like corn and soy.

Declining Migration Numbers

GMO crops like soybean and corn are engineered to by resistant to the herbicides used to kill weeds. The crops are treated with large amounts of the herbicides which kill in the immediate area.

The runoff of water spread the herbicides to the surrounding area, and the wind carries the herbicide far distances.

The use of the herbicides have storngly caused the demise of milkweed, and climate change to a lesser extent.

Monarch butterfly number have been on the decline for the last fifteen, but the most drastic drops have been in the last few years.

Scientist determine the monarch butterfly number by their coverage of the forests of Mexico, where they hibernate for the winter.

The monarchs covered 0.67 hectares of their wintering grounds in Mexico during the 2013-2014 winter. This is almost 10 times lower than the average winter coverage of 6.39 hectares form 1994-2014.