It has been 41 years since the discovery by Western researchers of a huge hibernation ground for the Monarch butterfly in Mexico dubbed “the Mountain of Butterflies.”
It officially became the Monarch Butterfly Biosphere Reserve in 1980 and was designated as a World Heritage site in 2008, but here are some of the things you may not know about this natural wonder:
Butterflies only inhabit a tiny fraction of the 56,000 hectare reserve.
Monarch butterflies – known by their distinctive orange and black wings – are found all over North America but they travel south through Texas into Mexico and follow the Sierra Madre Oriental Mountains to the reserve on the border of Michoacán state and the State of Mexico.
They live there between October and March but only occupy around 4.7 hectares of the reserve.
The butterflies are thought to cluster together to conserve heat during the winter months when the temperature can drop to 22 degrees Celsius.
They appear to turn the branches orange and make them sag under their weight.
Approximately one billion butterflies are believed to migrate there every year, and there is between six and sixty million butterflies living in each hectare.
Locals con pare the sound of millions of butterflies taking flight to go home in March to “light rain.”
Although it was officially ”discovered” in 1975, locals have know about it for years.
The butterflies were known even before the Conquistadors arrived from 16th century Spain.
In the language of the native Purépecha people – who came from the region – their name for the Monarch butterfly means “harvest butterfly” because they noticed it always arrived at the time of the corn harvest.
The butterfly has also been associated with the Dia de Los Muertos (Day of the dead) festival at the end of October, which coincides with their arrival.
According to traditional beliefs, the butterflies are supposed to be the souls of people’s ancestors who are returning for their annual visit.
The butterflies habitat in under threat.
Although it was designated a wildlife reserve in 1980, their habitat is still vulnerable to illegal logging, deforestation and the destruction caused by tourists.
Only two of the eight butterfly colonies are open to the public, but tourists regularly leave rubbish behind.
Illegal use of the land by farmers who want to turn it over to agriculture is also a major problem.
Although the butterflies themselves are not in danger of extinction, their migration to this site in Mexico could become a thing of the past if trends continue.
Controversial nerve agent pesticides have frequently been blamed for declining bird and bee populations. Now butterflies can be added to the list of species thought to be getting poisoned by neonicotinoids.
A new study by Stirling and Sussex universities has found the first scientific evidence that pesticides could be harming butterflies. Neocolonialists remain in the environment and can be absorbed by wildflowers growing at the edge of fields, which provide a source of nectar for butterflies and leaves for their caterpillars to eat.
“Our study not only identifies a worrying link between the use of neonicotinoids and declines in butterflies but also suggests the strength of their impact on many species could be huge,” said Dr. Andre Gilburn, an ecologist at Stirling University.
Dr. Tom Brereton, head of monitoring at Butterfly Conservation, said: “We are extremely concerned with the findings of this study and are calling for urgent research to see whether the correlations we found are caused by neonicotinoid use or some other aspect of intensive farming.”