Where Have All the Monarch Butterflies Gone?

The orange and black throng of monarch butterflies flocking to their winter home in central Mexico was drastically reduced this year, the country’s National Commission of Natural Protected Areas announced on Wednesday. The reasons are two things we’ve heard too much about: extreme weather and farmlands planted with crops genetically modified to resist insecticides.

The area of forest the butterflies occupy fell to its lowest level in 20 years in 2012, according to an annual census conducted in December, to 2.94 acres from a high of 50 acres. The exact number of butterflies themselves cannot be counted, so the combined size of their colonies is used to determine their numbers. Any way you look at it, the numbers of monarchs have been dwindling: in 2011, 7.14 acres were measured.

All told, the wintering monarch population in Mexico has dropped by 59 percent, with last year’s decline the sixth in seven years.

One factor was the record-breaking heat and drought that plagued North America where the monarchs migrate to in late spring, as Chip Taylor, director of the conservation group Monarch Watch at the University of Kansas, tells the New York Times. The monarchs’ breeding cycle was disrupted by the hot weather, which dried up their eggs and affected their source of food, milkweed, by drying up its nectar. Weakened, the butterflies laid fewer eggs.

As it is, the use of soybeans and corn genetically modified to resist pesticides has wiped out the milkweed that once grew on millions of acres, between the rows of crops. Milkweed also once grew plentifully on U.S. grasslands, but these have also disappeared with 25 million new acres devoted to farmland since 2007.

So many fewer monarchs spells trouble for the food chain, for the birds who eat insects and for the predators who pray on birds. Parts of Mexico also count on tourists who flock to see the marvel of crowds of monarchs and the Mexican government has halted what had been widespread illegal logging in the monarchs’ winter home.

At a news conference in Zitácuaro, Mexico, Omar Vidal, head of the World Wildlife Fund’s Mexican operations, called on the U.S. and Canadian governments to also do more. Specifically, he called on the U.S. “to do much more,” by taking measures to replenish milkweed.

Scientists including monarch expert of Lincoln Brower of Sweet Briar College in Virginia say that Mexico can still increase its efforts, too. As he says to the Guardian, he saw small-scale logging going on in the monarchs’ winter home in February. Even small-scale reductions in the forests can affect the butterflies, as these mean lower temperatures and changes in humidity and direct sunlight. Tourism itself is a problem, as it is insufficiently controlled.

Certainly the drastic decline in the population of monarchs is a call for cross-border collaboration. As Brower emphasizes, “the numbers are getting so slow now that the migratory phenomenon of the monarch is becoming endangered.” Nothing less than the “glorious migration phenomenon” is at stake. We can do something — better regulating and safeguarding their forest habitat and putting controls on the use of genetically modified crops — and we need to, to keep the monarchs from disappearing altogether.

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Photo credit: farflungphotos


Carrie-Anne Brown

very sad news but thanks for sharing

Debbie Crowe
Debbie Crowe3 years ago

All Butterflies are beautiful, but the Monarch is extraordinary! I have Milkweed in our yard, but I did only get 1 Monarch last year because of the drought. I will have to water more often this year!!

Sunny H.
Sunny H3 years ago

People need to realize it's herbicides like Roundup that's causing so much damage to our eco-system and health. There was a report on late night radio Coast to Coast about this last night and it was pointed out that Monsanto creates Roundup in the 1970's and then created Roundup ready GMO crops such as corn and soybeans. Lots of milkweed used to grow between these rows of crops which supported the Monarch. This could have a widespread impact on the fabric of life itself on earth. We love the Monarchs and it could go alot further. Monsanto is killing our ecosystem!
Link to article from program: http://www.earthfiles.com/news.php?ID=2081&category=Environment

Rebecca Mesa
Rebecca Mesa3 years ago

This is so sad. There was also a story on the news a couple of nights ago about this. The monarch numbers have been steadily declining. Deforestation has had a huge impact also. We have lost so much of our prairies and grasslands because of over farming, development, etc. I have tons of milkweed in my yard and gardens and I leave it there. I don't get as many monarchs as I once did though. It's disheartening.

Sarah Hill
Sarah Hill3 years ago

It is the same problem as the bees, pesticides.

Bill K.
Bill K3 years ago

oops - that should have been butterfly weed, not butterfly week

Bill K.
Bill K3 years ago

please plant milkweed plants in your garden this year. they are a family of perennial flowers (like the popular orange butterfly week) which monarch larvae need.

David V.
David V3 years ago

Humans are destroying every living thing on this planet. It is only a matter of time until everything is destroyed.....Mother Nature needs to get revenge before that happens.

Ernest Roth
Ernest R3 years ago

@ Simon T "third world families probably need twice as many children as us westerners to raise the same number" No there are many more third world families and they have larger families of which morer survive because of the help of well wishing and comparastively affluent westerners.@ Kate R. 'if the babies being born now were never able to see" Apart from that, consider the future for babies born now, and mourn for them . Their birth is a tragedy..@ Caropl M. "Unfortunately, there are so many people" You can put a period after that thought.

Ernest Roth
Ernest R3 years ago

@ Ruhee B."a safe place for all animals once the "destroyer" aka mankind has gone" If only. It's a lovely fantasy but I fear that there won't be any animals left after mankind has gone.
@ deborah H. Thanks for an excellent summary of the present world situation !. Bono is determined to imporove third world lives, but I don't believe that he has considered what to do about the consequences of the increased population that will be caused by his success..