Monarch Watch Blog

Monarch Population Status

14 March 2013 | Author: Chip Taylor

The World Wildlife Fund-Mexico / Telcel Alliance, in collaboration with Mexico’s National Commission of Natural Protected Areas (CONANP), held a press conference late on the 13th of March 2013 to announce the results of the status of the monarch populations that overwinter in the oyamel forests of Mexico. Measures of the areas occupied by each of the nine monarch colonies in the states of Michoacan and Mexico totaled 1.19 hectares. This number represents a decline of almost 59% from the area occupied the previous winter. Further, this population is the smallest recorded since the monarch colonies came to the attention of scientists in 1975. A visual inspection of Figure 1 reveals a clear downward trend in the population:

Figure 1. Total Area Occupied by Monarch Colonies at Overwintering Sites in Mexico

This decline is statistically significant* (analysis by Ernest Williams, Hamilton College):

linear regression: p=0.004, R squared = 0.402
exponential regression: p=0.001, R squared = 0.477

At issue is the cause of the decline and there are a number of factors involved:

1) The loss of milkweeds in row crops (corn and soybeans) due to the adoption of seed varieties genetically modified to tolerate treatment with herbicides. The utilization of these herbicide tolerant crops has all but eliminated milkweeds from these fields.

2) The push for the production of biofuels, which has resulted in the planting of 25.5 million more acres of corn and soybeans than were planted as recently as 2006. This increase has been at the expense of milkweed-containing Conservation Reserve Program land, grassland, and rangeland (as well as other crops).

3) Development, which consumes 6000 acres at day or 2.2 million acres a year.

4) Intensive farming that reduces the area from the edge of the road to the field and management of our roadsides with the use of herbicides (and excessive mowing) which also eliminates milkweeds.

5) Deforestation of the oyamel fir forests – although this has declined over the last few years, the condition of these forests is less than optimal for the survival of overwintering monarchs.

6) Unusual weather – and we had plenty of that during the 2012 monarch breeding season. March was the warmest recorded since nationwide record keeping began in 1895. Warm weather tends allow returning monarchs to spread north rapidly and arrivals of monarchs in areas north of Oklahoma in April are often followed by low temperatures that delay development of the population. In 2012, first generation monarchs moving north-northeast out of Texas arrived much earlier in the northern breeding areas than previously recorded. Historically, low overwintering numbers have followed the early arrival of monarchs. These early establishments were followed by one of the hottest and driest summers in recent decades. Hot and dry conditions probably have the effect of reducing adult lifespan and therefore the number of eggs laid per female over their lifetime.

All in all, it was not a good year for monarchs. While some of the present decline can certainly be attributed to the seasonal conditions last summer, it is the decline of monarch habitats in the United States and Mexico that is the major concern. The good news is that we can do something about the habitats in the United States and Canada – we can plant milkweed. That said, in order to compensate for the continued loss of habitat we need to plant LOTS AND LOTS of milkweed. To assure a future for monarchs, conservation and restoration of milkweeds needs to become a national priority.

Chip Taylor
Director, Monarch Watch

* p values indicate the probability of the outcome being due to chance alone. P values of less than 0.01 are considered to be extremely low. R squared represents the relationship between two variables. R square values range from 0-1. High values indicate that two variable are highly correlated.

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Monarch Butterfly Survey Points to Lowest Numbers in 20 years

13 March 2013 | Author: Jim


Press Release March 13, 2013

Monarch Butterfly Survey Points to Lowest Numbers in 20 Years

ZITÁCUARO, Mexico – The percentage of forest occupied by monarch butterflies in Mexico, used as an indicator of the number of butterflies that arrive to that country each winter, reached its lowest level in two decades. According to a survey carried out during the 2012-2013 winter season by the WWF-Telcel Alliance, and Mexico’s National Commission of Protected Areas (CONAP), the nine hibernating colonies occupy a total area of 2.94 acres (1.19 ha) of forest – representing a 59% decrease from the 2011-2012 survey of 7.14 acres (2.89 ha).

The survey was conducted in five hibernation colonies inside the Monarch Butterfly Biosphere Reserve (two in the State of Mexico, and three in Michoacán), and four colonies outside the reserve (three in the State of Mexico, and one in Michoacán). To carry out the monitoring, bi-weekly tours are conducted in the premises of the colonies which have been surveyed historically, by calculating the perimeter and systematizing the data with spatial analysis software.

“Colonies located inside the reserve occupied 78.2% of the total area (0.93 has), while colonies outside of the reserve occupied the 21.8% (0.26 has). The largest colony was found in El Rosario, Michoacán, occupying 0.63 has (52.9% of the total area). For the first time the survey registered a colony in the indigenous community of San Pablo Malacatepec, State of Mexico, with a total of 17 properties with colonies of hibernating monarch butterflies in Mexico,” said Luis Fueyo, Commissioner of CONANP.

The latest decrease in monarch butterflies is likely due to a decrease in the milkweed plant (Asclepias) – a primary food for monarchs – from herbicide use in the butterfly’s reproductive and feeding grounds in the US, as well as extreme climate variations during the fall and summer affecting butterfly reproduction.

“Extreme climate fluctuations in the US and Canada affect the survival and reproduction of butterflies. The monarch’s lifecycle depends on the climatic conditions in the places where they develop. Eggs, larvae and pupae develop more quickly in milder conditions. Temperatures above 95F can be lethal for larvae, and eggs dry out in hot, arid conditions, causing a drastic decrease in hatch rate,” said Omar Vidal, Director General of WWF-Mexico.

The butterflies that migrate to Mexico feed on milkweed in the soy and corn fields of the US. The use of herbicides to eradicate this plant, considered a toxic weed for cattle, has reduced the amount of available milkweed by up to 58%. “The conservation of monarch butterflies is a responsibility shared by Mexico, the US and Canada. By protecting its sanctuaries and practically eliminating large-scale deforestation, Mexico is doing its part. It is necessary that the US and Canada also do their part and protect the habitat of the monarch in their countries,” Vidal added.

“The WWF-Telcel Alliance celebrates 10 years of supporting the conservation and sustainable management of the natural resources of Mexico and the well-being of the people that depend on those resources. The Alliance has worked with local communities, the government and civil society to conserve the monarch forests in a way that benefits nature, local populations, and those that visit the Reserve. Among these projects is the development of sustainable business such as tree nurseries, mushroom production modules, and handicraft production, as well as the improvement of tourist infrastructure at El Rosario, and Cerro Prieto in Michoacán” said Marcela Velasco, Director of Marketing at Telcel.

Forest Area Occupied by Monarch Butterfly Colonies from 1993-2013.

Images available at:

For more information please contact:

Monica Echeverria at WWF-US
(202) 495 46 26

Daniel Bravo, at WWF-Mexico
(52-55) 5286-5631 ext. 246

Gustavo Aranda at Telcel in Mexico
(52-55) 2581 3700 ext. 5162

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Monarch Butterfly Conservation: The Challenges Ahead

25 February 2013 | Author: Jim

Monarch Matters: February 2013
By Candy Sarikonda, Monarch Watch Conservation Specialist

The OH Lepidopterists Society held its annual meeting in Columbus on January 19, 2013. The keynote speaker was Dr. Chip Taylor, Director of Monarch Watch. Dr. Taylor presented a power point presentation entitled, “Monarch Butterfly Conservation: The Challenges Ahead.”

Dr. Taylor began by briefly covering the dynamics of the monarch migration. He pointed out that the migration is very predictable, and seems to be associated with the declining angle of the sun. He described how the monarchs arrive in Mexico “virtually the same day every single year,” and their arrival coincides with the local festival, El Dia de Los Muertos, or Day of the Dead. For this reason, the native people of Mexico have long believed that the monarchs are the souls of their deceased loved ones, arriving to enjoy offerings from their ceremonial shrines, or ofrendas.

“The monarch migration is absolutely spectacular,” explained Dr. Taylor. But the monarch population is declining, and World Wildlife Fund has declared the monarch migration endangered. This winter, the monarch overwintering population in Mexico is likely to be the lowest ever recorded. Dr. Taylor predicts the population to be about 1.5 hectares, or less than 100 million butterflies. Why are the monarchs declining?

Dr. Taylor earnestly explained that global climate change is underway. “Monarchs are symbolic of what is happening, at some level, to everything that interests you—lepidoptera, birds, native vegetation.” He pointed out that for the past 16 years, U.S temperatures have been above the 20th century average. Global temperatures have been above the 20th century average for the past 36 consecutive years. He warned the audience that global climate change has started, and the effects of this change are coming rapidly. He urged, “We need to find a way to cope with the changes coming our way.” Increasing drought, severe storm events, and unpredictable spring and summer temperatures will become the new reality, and these changes will affect not only monarchs, but many of our native flora and fauna.

Dr. Taylor also described the impact that herbicide-tolerant (HT) crops have had on the monarch population. Using a series of graphs, he demonstrated how the monarch population declined coincident with the increased planting of HT corn and soybeans. HT crops were planted beginning in 1996, and began to be used widely in 2000. It was then that monarch scientists began noticing a decline in the monarch population. “Once HT crops represented 40% of the total acreage, we began noticing a significant decline in the monarch population.” Dr. Taylor and his colleagues estimate that 160 million acres of habitat, or roughly 20% of the breeding range of eastern monarchs, has been lost as a result of the introduction of HT corn and soybeans. Interestingly, he pointed out that shifting crop production and the use of Conservation Reserve Protected (CRP) land has also changed dramatically. During a period when farmland decreased by 10 million acres, corn and soybean acreage actually went up—representing a conversion of 25.5 million acres of CRP land, grasslands, range lands and acres previously used for other crops to corn and soybeans.

HT crops have resulted in the loss of monarch habitat. But also at issue is development. In the U.S., development has resulted in the loss of 6,000 acres of habitat per day, or 2.2 million acres per year. Additional habitat has been lost as a result of more intensive agricultural practices that reduce field margins, referring to the space between crops and the roadside. Increased mowing and herbicidal spraying of roadsides has diminished pollinator habitat. Mosquito spraying has detrimentally affected lepidoptera. The list goes on. It feels overwhelming. So what can we do?

Dr. Taylor described two programs he created, the Monarch Waystation program, and the Bring Back the Monarch (BBTM) campaign. Both programs aim to increase the planting of milkweed and the creation of pollinator-friendly habitat. The Monarch Waystation program encourages members of the public to create pollinator-friendly garden habitats at homes, schools, businesses, nature centers and preserves. Citizens can then certify the habitat site through Monarch Watch, and display a metal sign identifying their site as a Monarch Waystation. By certifying the site, citizens can show support for monarch conservation, and displaying the Waystation sign helps educate the public about this conservation effort. The BBTM campaign is a milkweed restoration campaign, which aims to restore native milkweeds by collecting seed, identifying restoration opportunities, growing and supplying milkweed plugs for restoration efforts, and creating partnerships between organizations with the ultimate goal of increasing monarch habitat.

What else can we do to improve monarch habitat? We need to change our mowing practices. Protect our roadside native vegetation. Stop spraying herbicides, and mow less frequently or not at all. Speak up and tell city officials that we do not want them to mow or spray, and pat them on the back when they listen. Ask local plant nurseries to carry milkweed and native plants that are pesticide-free. Volunteer on nature preserves and at city parks—encourage management to plant milkweed. Collect milkweed seeds. Monitor a milkweed patch. Educate the public—through school programs, talks at local libraries, displays at nature centers, articles in the newspaper or on radio—by any means we have at our disposal. Realize that no one person can do it alone, we all have to pitch in—and every one of us has a voice that is valuable.

Throughout the presentation, Dr. Taylor referred to the new Imax 3D film, Flight of the Butterflies. He shared his experience of the film and said, “There is a shot at the end of the film where butterflies cascade off the trees in unimaginable tens of thousands, and the sky turns orange…suddenly, you become aware of the fact that much of what you are hearing, throughout the film, is the rustle of butterfly wings. How many times have you been to a place where the predominant background sound is the rustle of insect wings?”

Let’s do everything we can to make sure we keep hearing those wings.

For more information on the monarch decline, see “Decline of Monarch Butterflies Overwintering in Mexico: Is the Migratory Phenomenon at Risk? by Brower et al. 2011 at

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Milkweeds – place orders now

19 November 2012 | Author: Chip Taylor

monarch on milkweedGreetings: I need to get milkweeds off my mind (all that latex is messing up my brain) and into the ground.

I spend a lot of time trying to figure out how to build a market for milkweeds and it’s going slowly – poco a poco as they in Spanish speaking countries. We need to make more progress. Our impact is still too small. We have some long range plans but they are still long range and we need to ramp up the milkweed plantings in the near term.

Thanks to many of you, we have seed – lots of it for most of the northeast (from MN to MA) and Texas and now we need orders for plugs. That’s where you can help.

We are working with a grower who produces terrific milkweed plugs, mostly for delivery in May but, we are going to try to have some ready for April. The plugs come in flats of 32 and are generally 3-4″ high, although incarnata (swamp milkweed is taller) and will cost about $1.80 each delivered (i.e., $57.60/flat with shipping included). The minimum order is one flat. Smaller plants in 72 unit cell trays (flats) will be available for some early April orders for a lower cost per plant. The shipping boxes hold two flats. So, it is a little less costly to order two flats at a minimum.

To have plants of optimal size for shipping in April and May, they need to be started in January and we need to have orders by December.

The question is: can you help us with these orders? We are trying to connect with native plant societies, nature centers, zoos and botanical gardens, master naturalists, master gardeners, and restoration projects – just about anybody that would be interested in distributing milkweeds through plant fundraisers or other means.

We use geographically-appropriate seed sources for the production of plugs and we do not supply tropical milkweeds.

For most of the northeast we have A. syriaca (common), A. incarnata (swamp), and A. tuberosa (butterflyweed) and for Texas we have A. viridis (green antelope horn) and A. asperula (antelope horn) and possibly A. oenotheroides (zizotes). We have seeds for some other species and regions as well. Please contact us if you have questions.

If you can connect us with buyers, that would be very helpful. Please send all inquiries, comments, or suggestions to us via Monarch Watch’s Bring Back the Monarchs campaign at

Thank you for your help.

P.S. Monarch Watch does not benefit financially from these arrangements.

Chip Taylor
Director, Monarch Watch

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Chip in for Monarch Watch

21 August 2012 | Author: Jim

The 2012 “Chip in for Monarch Watch” Fundraising Campaign is now underway! Please help us spread the word about this annual campaign which brings in funds to keep Monarch Watch’s education, conservation and research programs going…and growing!

If you are in a position to offer financial support to Monarch Watch (or if you know someone who might be), please consider making a fully tax-deductible donation of any amount during our 2012 “Chip in for Monarch Watch” fundraising campaign.

Visit for more information or to submit your pledge and tax-deductible donation. Be sure to check out the comments and photos submitted by other donors – we are continually amazed by the connections that are made through monarchs and Monarch Watch.

Last year’s campaign was a huge success, raising more than $31,000 – think we can top that this year? smiley

Complete campaign details at:

Thank you for your continued support!

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Monarch Population Status

20 August 2012 | Author: Chip Taylor

In early July I wrote the text for the pre-migration newsletter that goes out with the tagging kits in which I stated that there was no real basis for making a prediction about the size of the fall migratory population:

“If there is sufficient rainfall and normal to above normal temperatures in the northern breeding range through August, the migratory population may be the largest since 2003 – perhaps 6-7 hectares. On the other hand, a continuation of the extreme heat and drought conditions could result in another overwintering population in the 2-3 hectare range – well below the long-term average of 7 hectares.”

It is now clear that fall population will be on the low side with an overwintering population close to 3 hectares once again. I don’t need to tell you that the summer was hot and dry – too hot and dry in many areas for good monarch reproduction. We have received many comments on the poor quality of the milkweed available to monarchs for the last generation. In eastern Kansas, where the drought ranges from extreme to exceptional, milkweeds, even blue vine (Cynanchum laeve), suitable for egg laying, are scarce. The best areas for the production of fall migrants appear to be northwest and central Minnesota, northern Wisconsin and Michigan, and much of New England. Reports from New England suggest that the number of monarchs passing through Cape May will be higher than normal this fall. Elsewhere, we can expect the number of fall migrants to be similar to that seen over the last several years.

The low number of nectar sources that will be available to monarchs moving through the lower Midwest in September is a concern. Some fall flowers have already bloomed, some have died and many of the others are stunted and just barely alive. There will be nectar but it will be harder for the monarchs to find. Rain in the areas of Nebraska, Kansas, Oklahoma, Missouri, Iowa, Arkansas, and Illinois over the next three weeks could make a big difference in the proportion of the fall migrants that reach Mexico.

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Monarch Tagging Kits

20 August 2012 | Author: Jim

Tags for the 2012 fall tagging season are still available but going fast – more than 75% of this year’s tags have been claimed to date. If you would to tag monarchs this year, please order your tags as soon as possible.

Monarch Watch Tagging Kits are only shipped to areas east of the Rocky Mountains. As usual, each tagging kit includes a set of specially manufactured monarch butterfly tags (you specify quantity), a datasheet, tagging instructions, and additional monarch / migration information. Tagging Kits for the 2012 season start at only $15 and include your choice of 25, 50, 100, 200, 300, or 500 tags.

Monarch Watch Tagging Kits and other materials (don’t forget to pick up a butterfly net!) are available via the Monarch Watch Shop online at – where each purchase helps support Monarch Watch.

Datasheets and instructions for the 2012 season are also available online at

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Monarch Population Status

30 July 2012 | Author: Chip Taylor

A year like no other…

There has been no year in the 117 years of climate records for the United States that matches what we have all experienced in the last 12 months. We have been tracking how monarchs are affected by climate for a number of years and there have been obvious patterns, like cooler March temperatures in Texas are associated with larger overwintering populations in Mexico. Similarly, warmer May temperatures are more favorable since they favor re-colonization of the northern breeding areas. Also, warmer summers in the northern breeding range are better for monarch production.

This year, however, is off the charts. March was the warmest recorded in Texas – not a good start based on past records. May was also warm, allowing monarchs to move into the northern breeding areas earlier by two to three weeks and in numbers that were unprecedented. Early arrival in the north in the past has been associated with population declines but in those years the average summer temperatures were in the normal range. This summer is starting out to be different from other summers with June temperatures exceeding the norm over most of the northern breeding area. What will happen this year with early arrivals followed by a warm summer, possibly one of the hottest summers ever recorded?

Not only has it been warm, it’s been hot and dry – perhaps too hot and dry for good monarch reproduction. And, then there are the milkweeds and nectar plants to consider. Plants grew rapidly this spring with many species blooming 10-30 days earlier than normal. Plants that typically flower in the fall began blooming in June and reports continue of water stressed plants blooming early. Milkweeds were no exception with flowering being earlier almost everywhere, raising the question as to what their condition they will be in the last week of July and the first week of August when most of the eggs are laid that produce the migratory generation cialis. If the milkweeds are past their prime, and are senescing, will this diminish the size of the last generation?

There are also questions as to whether large numbers of monarchs overshot (that is, flew beyond) the limits of milkweed. Unprecedented numbers of monarchs have been reported from the Prairie Provinces of Canada where milkweeds are scarce, from the Maritime Provinces where monarchs are usually few, and even from Newfoundland, an area with virtually no milkweed. As you can see, there are many questions but little basis for making a prediction as to the size of the fall migration. If there is sufficient rainfall and normal to above normal temperatures (+/-80F) in the northern breeding area through August, the migratory population may be the largest since 2003 – perhaps 6-7 hectares. On the other hand, a continuation of the extreme heat and drought conditions, a track that seems equally likely, could result in another overwintering population in the 2-3 hectare range – well below the long-term average of 7 hectares.

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Our Amazon Earnings – 2012 Q2

8 July 2012 | Author: Jim Lovett

As you may already know, you can help support Monarch Watch with each purchase at and (Amazon’s specialized Shoe and Handbag store). Monarch Watch earns a small referral fee equal to 4-15% of the item total when you use the links available on our site to visit these online stores.

In the second quarter of 2012 (Q2, April-June) 765 items were ordered in support of Monarch Watch, earning our program $1115.58!

A complete list of items will be available for those that are curious to see what folks are buying to support Monarch Watch. (Note: No personal information is tied to purchases; that is, we do not know who purchased the items below, only that the items were purchased via the link(s) from our site and therefore in support of our program.)

amazon stats graph

Since February 2009, 5589 items have been ordered – earning $8692.56 for Monarch Watch!

Thank you to everyone who contributed to these numbers – remember to stop by our site first whenever you shop online!

Complete details are available at

Please help us by spreading the word to friends, family, coworkers, and any other or shoppers you can think of – thank you for your continued support!

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Monarch Population Status

12 June 2012 | Author: Jim

What a spring it’s been – the warmest in 117 years of record keeping and the warmest 12 months ever recorded in the United States. In response to the warm conditions the plants and insects have made early appearances. Some plants bloomed 6 weeks early, others a more modest 2 weeks. Most insects appear to have kept pace including monarchs that arrived 2-3 weeks early over most of the northern breeding range – raising the possibility of a large fall migration – maybe the last big migration this decade.

Climatologists are telling us that hotter summers with strong droughts are ahead and that won’t be good for monarchs. Habitat decline will continue as well so, let’s tag while we can. We have ordered tags for the 2012 tagging season and the orders are coming in rapidly. If you would to tag this fall, please order your tags early. If your fellow monarch enthusiasts see a large migration shaping up, we are likely to be out of tags by the 1st of September. Please place your order now so as not to be disappointed.

Monarch Watch Tagging Kits are only shipped to areas east of the Rocky Mountains.

As usual, each tagging kit includes a set of specially manufactured monarch butterfly tags (you specify quantity), a datasheet, tagging instructions, and additional monarch / migration information. Tagging Kits for the 2012 season start at only $15 and include your choice of 25, 50, 100, 200, 300, or 500 tags.

Monarch Watch Tagging Kits and other materials (don’t forget to pick up a butterfly net!) are available via the Monarch Watch Shop online at

Filed under Monarch Population Status, Monarch Tagging | 1 Comment »