Michoacán State is famous
for the Monarch Butterflies. They migrate from the North every
year and stay from October to March to protect themselves from
winter and to breed. The state is also famous for its craft.
Located in the State of Michoacán,
115km (72 miles) from Morelia,
the Mariposa Monarca Biosphere Reserve occupies 152,461
acres close to the province of Mil Cumbres and is comprised of
a group of mountains and hills. The highest points culminate around
3,600 m (11,800 ft) of altitude. The soils are made of light volcanic
ashes whose water retention capacity is very high. In the lowest
part, at 1,500m (4,920 ft) of altitude, some conifers start to
grow and they are more and more as you go up. From 2,400m (7,870
ft), there are oyamel firs (Abies religiosa), cedars
(Cedrella odorata) and cypresses (Cupressus sp).
Higher, at 2,900m (9,515 ft) of altitude, the cedars disappear
to allow room for ranges of oaks (Quercus sp), oyamel firs and
pines (Pinus sp), and above 3,600m (11,800 ft), the oyamel firs
are the dominant vegetation with a few bushes, mushrooms and epiphyte
plants. The conifer species “Abies religiosa”
holds a very high humidity level and is able to resist low temperatures,
which is the preferred habitation for the Monarch butterflies.
This phenomenon of migration of the Monarch butterflies intrigued
the entomologists and biologists :
Why thousands and thousands of orange and black Monarch butterflies
migrate from Canada and North of the United States (Rocky Mountains)
to Mexico and back ?
When the nights become longer and the temperatures colder, this
famous migrant butterfly flies thousands miles from Canada to
Mexico. There, it spends the winter before going
back, during the spring, to the northern countries to lay their
eggs. The cities of Angangueo, Ocampo and Zitacuaro house the
most important sanctuaries. The migration is estimated to 20 million
butterflies per season !
picture : monarch butterfly
July 2008 : The Monarch Butterfly Biosphere Reserve is a new Mexican
natural site inscribed on the UNESCO World Heritage List.
Extract of the UNESCO site : "The 56,259 ha biosphere lies
within rugged forested mountains about 100 km northwest of Mexico
City. Every autumn, millions, perhaps a billion, butterflies
from wide areas of North America return to the site and cluster
on small areas of the forest reserve, colouring its trees orange
and literally bending their branches under their collective weight.
In the spring, these butterflies begin an 8 month migration that
takes them all the way to Eastern Canada and back, during which
time four successive generations are born and die. How they find
their way back to their overwintering site remains a mystery".
The Monarch Butterflies were born around the Great lakes, in the
farming regions of the Canadian South-East and the north-East
of the United States, in the corn and soy fields. Here, grows
a perennial plant called Asclepias. It is a plant with
clusters of yellow flowers and reddish peduncles linked to a stem
filled with latex, a toxic substance stored by the butterflies
in order to protect themselves from the predators.
Because it is an Asclepias, this plant is also called
milkweeds and it has been used for thousands of years in the countries
as a poison against the rodents and in herbalist’s shop
as antiseptic and to cure constipation. It is also known to relieve
rheumatism and tooth pains or provoke vomiting. The Monarch Butterflies
lay their eggs on only 27 over the 108 species of Asclepias
studied in North America. These species are able to bring the
defenses and energy needed to make their annual migration.
picture : monarch butterfly
The confirmation of this migration was confirmed only in 1975.
The Odyssey lasts one month. They fly several kilometers a day,
up to 130 km (80 miles) when the winds are favorable, before reaching
one of the thirty overwintering zones located in central Mexico.
They use the atmospheric currents that allow them to plan for
3,900 km to 4,500km (2,400 to 2,800 miles).
When the sun warms the winter, thousands of butterflies cover
the trunks and branches, creating a mobile sky and ground made
of tiger aisles, breaking the profound silence of the forest.
The scientists explain that the Danaus plexippus (scientific name)
leave grease on the bark of the trees and on the ground to attract
the next generations of butterflies. The Monarch Butterfly migrates
only once to Mexico. According to the studies,
it lives about 9 months while other butterflies live only a few
weeks, or even a few days. The scientists haven’t figured
out yet the mystery of orientation to go from one point to the
In the spring, the butterflies naturally make their migration
to the Canada and go back to Mexico in the fall.
The Purépecha Indians
interpreted the arrival of the butterflies as a visit from their
deceased because it happened just before the ceremonies celebrated
to venerate the ancestors, ritual linked to the Christian celebrations
during the reign of the Spanish viceroyalty. The Mazahuas and
the Otomís called this insect the Cosechadora
(combine harvester), referring to the cycles of farming production.
A lot of butterflies died because of the natural elements like
cold and snow falls as well as the deforestation and the spreading
of pesticides. The government of President V. Fox (2000-2006)
became aware of the importance of the protection of theses butterflies
and decided to establish more reserves. The preservation of the
sanctuaries is also one of the priorities of the actual government
of Calderón (2006-2012). The conservation of this Biosphere
Reserve is the result of intense efforts conjugated from the local
and federal governments, the States, the WWF-Mexico,
national and international organisms financed by private companies
and community organizations of the region. As part of the reconversion
of productive activities, huge efforts have been made during the
last past years to encourage the biggest number of families, especially
from an indigenous origin, really understanding the durable development
(their economy was based, still recently, on the mining industry
and the forestry plantation). It is only if they are educated
and aware of the many opportunities offered by a protected place
such as this one that they will be able to harmonize their efforts
with the actions of conservation.
Read a beautiful and very complete article "Hinterland Who’s
Who” about the Monarch Butterfly : .
Canadian website in English/French.
There is also an interesting article from "Parks Canada” : (article in english/french).
Consult also the Website of Kansas University :
You could see then flying in huge clusters and always reaching
the same isolated parts of Michoacán. They take flight
in September/October for breeding during the dry season.
When they reach the neo-volcanic axis, they establish themselves
in hibernation colonies, using branches from the oyamel
(Mexican conifer tree) in the Southwestern sides of the
forests, where they stay for 5 months from when they arrive
in October until they leave the end of March. After a mating
period of one month, the butterflies that survived the wintering
go back from where they came.
Visita al Santuario
de Mariposas Monarca "El Rosario" en Michoacán,
of the sanctuary of monarch butterflies in the state of Michoacán
Take a tour from Morelia
to get there more easily and to get good information about this
mysterious migration (entrance fee: $25 plus tips for the guides;
open 10 AM-5 PM, daily from mid-November to March). Allow a full