Mexico 2018 part III - Monarch Butterfly Biosphere Reserve

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Monarch butterflies en masse

In 2009 I went to Mexico and visited the Monarch Butterfly Biosphere Reserve. When my mother saw my photos from there she felt that she really wanted to see this phenomenon for herself one day. It took nine years but now finally we went there.



Before anyone check out the blog entry I wrote in 2009 and accuse me of plagiarism I admit right away that I have here reused some of the text I wrote then. I am writing about the same place so it's not like there is much I can say that I didn't say then.



Monarch Butterfly Biosphere Reserve is a sanctuary in the highlands of Mexico protecting the winter habitat of the monarch butterfly. In the summer the monarch butterflies live in North and Central America as far north as southern Canada. These butterflies have a very interesting strategy in order to survive the winter - they migrate.



Each year somewhere between 50 and 100 million monarch butterflies live in a few forests in central Mexican highlands. Why they choose the highlands where the temperatures actually go down below freezing point at night is a mystery at least to me. I mean if I was a monarch butterfly I would rather spend winter at a beach in the Yucatan Peninsula. But I guess the butterflies have a reason for staying in the mountains.



The butterflies arrive in October and stay until March. When the weather is starting to get better they leave their winter habitat and start to fly north. In the middle of the summer the butterflies have come as far as the great lakes at the border between Canada and USA.



Soon after the butterflies arrive in southern Canada they start to fly down towards Mexico again. This is where it starts to get interesting. The butterflies that were in Mexico at New Year are at this point all dead. They have all died simply because their life span is too short to allow them to fly all the way from Mexico to Canada. So the butterflies that now start flying back south are the children or grandchildren of the butterflies who started the journey up north in March. Most of the butterflies who leave Canada in summer to migrate south will not make it to Mexico either for the reason given above.



It actually takes from three to five generations of butterflies to make the journey from Mexico up north in the USA and into Canada and then back to Mexico. It is amazing how these insects can find their way back to the same forests as their ancestors up to five generations back stayed in the winter. How they do it I don’t know. I guess they are genetically programmed to do this journey every year. Either that or they have some kind of trail of pheromones they follow.



To put things in perspective: I live in central Stockholm in Sweden. Drop me off 15 kilometres from Stockholm Central Station in any direction and I can’t find my way home. These insects, whose entire mass is less than 1% of my brain weighs, can find their way from Canada to Central Mexico without ever having been near the place. I find that amazing.



In the winter the monarch butterflies mainly sit in large clusters half way up the trees. They sit in these groups to preserve energy and prevent heat loss. When the sun shines in daytime and the butterflies get a bit warmer some of them fly away and look for food. So in daytime there are hundreds or even thousands of butterflies flying in the air.



I visited Monarch Butterfly Biosphere Reserve in December which is the coldest time of the year. There were plenty of butterflies in the air in the afternoon but the vast majority was still sitting in the trees. I guess that in February and early March there are many more butterflies flying around. It would be interesting to go back there then and see that.



Hope you enjoyed reading this. I can ensure you that my mother and I both enjoyed visiting this place.

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Photos

Monarch butterfly
Monarch Butterfly Biosphere Reserve is a sanctuary in the highlands of Mexico protecting the winter habitat of the monarch butterfly

Monarch butterfly
When visiting the Monarch Butterfly Biosphere Reserve so you don't accidentally step on a butterfly.

A monarch butterfly
If you are careful the butterflies might come and sit on you

They stay in Mexico for five to six months every year
The butterflies arrive in October and stay until March.

They migrate from Mexico to Canada and back each year
These insects, whose entire mass is less than 1% of my brain weighs, can find their way from Canada to Central Mexico without ever having been near the place

Four butterflies
It actually takes from three to five generations of butterflies to make the journey from Mexico up north in the USA and into Canada and then back to Mexico.

IMG_1966
Each year somewhere between 50 and 100 million monarch butterflies live in a few forests in central Mexican highlands.

Swarms of butterflies
When the sun shines in daytime and the butterflies get a bit warmer some of them fly away and look for food.

Thousands of monarch butterflies
In daytime there are hundreds or even thousands of butterflies flying in the air.

Fascinating scene
We just stood there and watched this. The sky was filled with flying butterflies

Drinking water
Some monarch butterflies that are drinking water

Mural in the local school
It is a little bit funny, isn't it?

Migration information
At the visitor centre they had this mural saying that the monarch butterflies migrate 4000 km.

Mural
They are proud of the monarch butterflies in Mexico. This mural in town says so anyway

Posing in the sun
If you are a monarch butterfly it is nice to sit in the sun for a while

Do any other insects migrate?
These butterflies have a very interesting strategy in order to survive the winter - they migrate.

His/her great grandparents spent July in a meadow outside Toronto, Canada
In the summer the monarch butterflies live in North and Central America as far north as southern Canada.

Warming in the sun
But in winter they all go back to Mexico and stay in the highlands.

Clusters of butterflies
In the winter the monarch butterflies mainly sit in large clusters half way up the trees.

Clusters of butterflies
They sit in these groups to preserve energy and prevent heat loss.

The tree branches can crack
It has been known to happen that so many butterflies sit on one and the same branch that it breaks from the weight

How large do they get?
Some of the monarch butterflies can grow very large...

Comments

[D MJ Binkley]

California
We saw a similar thing in California on a much smaller scale. Would love to go to Mexico and see this. Thanks for sharing.

[Ake Och Emma]

I've recently heard of the California sites
I heard of the monarch butterflies sites in California only this year. I guess the butterfies have gone there too for the winter for hundreds of years. /Ake

[RENanDREW]

Wow!
I would never have guessed that butterflies cluster together like this. Love the photos of them in flight - what a beautiful phenomenon :)

[Ake Och Emma]

It is very spectacular
It is an very spectacular. In the nature there are few phenomena that can match this. /Ake

[Sheri Schroeder]

Monarch Butterflies
I was fascinated to see all the butterflies in Mexico! This summer, I observed the great migration south as I vacationed in northern Michigan. They all waited for the right winds to cross Lake Michigan from the Upper to the Lower Peninsula, a nearly 5 mile distance over water. As I swam in Lake Michigan, there were butterflies constantly floating by my head. Nice to know they made it all the way south to Mexico! Thanks for sharing.

[Ake Och Emma]

It must have been wonderful
It sounds like a wonderful experience to swim and have hundreds of butterflies flying over you. If I was a filmmaker I would have that as an opening scene in my next flick. Thanks for sharing your experience with us. /Ake