Monarch butterflies head north as Mexican scientists try to move their forest

One of the hottest winters in history poses good news and bad news for migrating Monarch butterflies this season. The good news: warm weather and well-timed rains translate into a grand wildflower season with plenty of milkweed in South Texas. The bad news: those same high temperatures in Mexico where the Monarchs overwinter mean that many butterflies have burned up much of their stored winter fats, creating a lack of fuel and extra stress for their journey north.

Some of the migrating creatures that arrived in the Mexican mountains last fall have already left the roosting sites. In fact, we found our first-of-season caterpillar this week on Tropical milkweed, Asclepias curassivaca, along the San Antonio River Walk.

But the bulk of the overwintering butterflies have yet to depart, head north and lay the first round of eggs that will launch the 2017 edition of their epic multigenerational migration. The success of that first generation, often born in Texas, sets the stage for a successful-or-not Monarch butterfly season. Subsequent generations make their way north to Canada over the summer, reproducing along the way. In the fall, they fly home to Mexico to roost until one day in March, they leave for good, head north, reproduce and die–starting the cycle anew.

first instar

First instar Monarch caterpillar found on the San Antonio River, March 9, 2017. Photo by Monika Maeckle

A recent trip to the roosting sites in Mexico found the butterflies fluttering from their roosts on the sacred firs in search of water and nectar–not unusual this time of year. The butterflies puddled in the damp mud of shallow mountain streams to rehydrate and sip nutrients. They also nectared on stands of asters, sages and various verbenas. Many butterflies lay dead on the ground–again, not unusual.

According to Dr. Cuauhtémoc Sáenz Romero, a forest geneticist at the University of Michoacán, the winter storm of March 2016 punched dangerous holes in the forest canopy. An intact canopy serves as a blanket for the butterflies and prevents temperatures from dropping below freezing, while the butterflies wait out the winter in a semi-hibernative state.  A lack of activity in the context of cold weather and insulation provided by the forest helps them conserve lipids (previously accumulated fats in their bodies), needed for the spring remigration. Gaps in the forest canopy and hot temperatures–the warmest winter in history–force the butterflies to burn up their fats.

Sáenz Romero expressed concerns that the condition of the forest coupled with climate change could have devastating consequences when the weather turns chilly and humid. This creates a deadly combination, forming ice on the Monarchs’ wings, he said, often causing their death.

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                                             photos by Nicolas Rivard

Such concerns motivated Sáenz Romero, ecological sciences professor Arnulfo Blanco García, and a crew of University of Michoacán students to establish an experimental forest plot on the Ejido La Mesa en Sierra Campanario near San Jose del Rincon in the state of Mexico.

While the area officially serves as a Monarch sanctuary and is part of the Monarch Butterfly Biosphere Reserve, few butterflies were present upon our visit there earlier this month. Signs of high temperatures, drought and the March 2016 storm that decimated more than 100 acres of forest and millions of butterflies were evident, however.

Sáenz Romero pointed out trees with skinny tops and a lack of foliage, which suggests a lack of water. A wet season and dry season typify the usual weather pattern here, he explained. But when the wet

Drought and high winds make the trees where the Monarchs roost vulnerable. Photo by Nicolas Rivard

season offers less rain than average and the dry season is warmer than usual, the trees can’t absorb enough water from the soil to reach the tallest limbs. Leaf and branch shedding result, creating weakened, scrawny treetops. This unhealthy state also makes the forest more susceptible to wind damage and insect attacks, said Sáenz Romero.

It wasn’t always this way, said Blanco García, taking in the vast expanse of oaks, pines and Oyamel, preferred by overwintering Monarchs. This area of Mexico has long relied on mining, which has posed different threats to the forest in the past, such as water pollution and deforestation.

Three-year-old Oyamel, sacred fir,  planted in full sun. Photo by Nicolas Rivard

Three-year-old Oyamel, sacred fir, in mixed plant community that provides partial shade. Photo by Nicolas Rivard

“Sixty years ago, there was no forest here,” he said. “But when mining stopped in the area, the forest regenerated itself.”  That was before climate change became the dominant factor it is today.

Saáenz Romero and Blanco García believe that within 70 years, the sacred firs hosting the Monarchs each winter will not be able to survive the increased temperatures and volatile weather predicted to rule the forest. The tree has a narrow window of temperature and altitude in which it can thrive, said Sáenz Romero.

With funding from Monarch Butterfly Fund in Minnesota, the Mexican Council of Science and TEchnology (CONACyT in Spanish), the Mexican Fund for the Nature Conservancy and the University of Michoacán, an experimental plot of Oyamel seedlings was placed  1,000 feet higher up the mountain than the existing sanctuaries–at 3,440 meters/11,286 feet. The approach, called assisted migration, has been successfully deployed in Canada. It aims to grow a replacement forest that in this case can be occupied by overwintering Monarchs when the roosting sites further down the mountain expire.

During a tour of the plot, now three years old, the scientists pointed out how Oyamel seedlings planted in combination with sage bushes and other tall perennials fared better than those placed in full sun. Because of the more severe dry season and higher temperatures, the Oyamels do better in a diverse plant community that offers shade at least part of the day.

“Weather proof” temperature monitor at the experimental forest in La Mesa. Photo by Nicolas Rivard

Also evident: the team’s unique resourcefulness. As students measured temperatures and moisture levels of the soil, an upside-down styrofoam cup wired to a stick raised questions.  What is that?

“It’s our weather proof temperature monitor,” said Blanco García.

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Monarch butterfly migrating population drops 27%, freak sleet storm to blame

Officials in Mexico announced Wednesday that the population of migrating Monarch butterflies dropped 27% this season, marking a setback in two consecutive years of growth from the historic low of 2014. A freak sleet storm gets the blame.

Piedra Herrada

Our friend Regina Moya went to visit la familia in Valle del Bravo with a side trip to Piedra Herrada Sanctuary in the state of Mexico. PHoto by Regina Moya

Just last year, we celebrated a tripling of the population, a reassuring turn of events from the grim news of 2014 when the total migrating population of Monarch butterflies could fit into a single Wal-Mart store with 30,000 square feet to spare. That sad fact had butterflies occupying only .67 hectares (1.65 acres) of high elevation forest at their winter roosting grounds in Michoacán and the state of Mexico. The numbers grew in 2015 to 1.13 hectares (2.8 acres), then jumped in 2016 to 4.1 hectares (10 acres).

This year, the butterflies covered only 2.91 hectares (7.19 acres).

Scientists and conservationists estimate the population by counting the number of hectares occupied and multiplying the estimated number by 50 million Monarchs per hectare. That suggests this year’s population numbers 145.5. million. The goal of conservationists is to rebuild the population to its historic average of 6.07 hectares (15 acres), or about 300 million butterflies.

The scene at El Chincua sanctuary  two weeks after the February 2016 storm.
Photo by Dr. Isabel Ramírez

Scientists and others who follow Monarch butterflies were not surprised by the findings. Dr. Lincoln Brower said by phone that he thought the numbers would be even worse. Many of us noted fewer Monarch butterflies than usual. Ruth Bowell of Troy, Ohio, shared her thoughts on the 2016 season on the DPLEX-list, an email listserv that reaches about 800 scientists, citizen scientists and Monarch butterfly fans. “My numbers this year were dismal until late August when I started really seeing caterpillars…If they have a good winter, maybe we’ll see more returning than last year.” Dr. Cuauhtémoc Saenz Romero, who studies the forest where the Monarchs roost, expressed the same sentiment, remarking “That was due to the winter storm in March.”

The storm to which he refers quashed the optimism of February 2016’s dramatic population growth within a few weeks of its announcement when, on March 11, climate change dealt a deadly blow to the rebounded Monarch population. A freak freeze and sleet storm descended on Mexico’s Monarch Butterfly Biosphere Preserves, decimating 100 acres of Oyamel firs and killing an estimated 50 million butterflies. The tragedy occurred at a most vulnerable time. Typically the first and second week in March are when the Monarchs begin to flee the forest and head north for South Texas in search of milkweed on which to lay the first generation of eggs.

Those of us who live in the flyway hoped for a robust recovery over the course of the spring and summer breeding seasons. The weather cooperated, but apparently even good conditions–plenty of rain in the Texas Funnel, ample milkweed and nectar plants in the spring and fall–couldn’t make up for season’s cursed beginning.

Monarch butterfly population numbers. Graphic via Journey North

Omar Vidal, head of the Mexico office of the World Wildlife Fund, told the Associated Press that the unusual winter storm likely played a role in the steep dip in Monarch numbers. “The reduction in the area of forest they occupied this year is most probably due to the high mortality caused by storms and cold weather last year,” he said. Here’s the full report, in Spanish.

Conservation efforts including pollinator habitat restoration and outreach continue, but it remains to be seen if that will be enough. Just today, the National Wildlife Federation, NWF met in San Antonio, the first Mayor’s Monarch Champion City, and finalized the completion of a citywide Monarch butterfly conservation plan. The document, assembled over several months and with the input of more than a dozen local organizations under the umbrella name Alamo Area Monarch Collaborative will lay out a comprehensive conservation and pollinator habitat restoration strategy. The effort will kick off and the plan shared at the upcoming San Antonio Monarch Butterfly Festival March 4 -5 at the San Antonio Zoo.

“During the meeting, the population count from Mexico was announced,” said Grace Barnett, Monarch Outreach Coordinator, South Central Regional Center for NWF. “It was read aloud–a strong reminder of  how important our work is and how much more there is to be done.”

Vidal underscored the work ahead when he told the Associated Press, “We cannot control the climate, but we can do much better in eradicating illegal logging in the reserve and tackling habitat loss in the U.S. and Canada,” Vidal said. “But, even if Mexico’s overwintering sites never lose another tree, without food and habitat along the migration routes, the forests will soon bid farewell” to the Monarchs.

Reports from the sanctuaries have been extremely upbeat, including one issued the same day as the declining population report. Journey North shared its first bulletin from roosting grounds correspondent Estella Romero, coupled with a note that tried to manage readers’ expectations with a prediction that numbers would be low this year.

Estela Romero of Journey North visited the roosting sites last week and raved about what appeared to be high numbers. But the population actually slipped from last year. Photo via Journey North

Under the headline “Population News: Waiting for the Official Count” Elizabeth Howard, founder of the citizen science initiative that tracks the migrations of Monarchs and other species, warned that observations made throughout the year suggested “a small population has been predicted — perhaps as low as 1 hectare.”

But Romero was effusive in describing her recent visit to El Rosario and El Chincua sanctuaries on February 4, sharing a dispatch hailing their seemingly high numbers.

“As I got nearer to the core of the colony, I just could not believe my eyes! It seemed as if I was looking to one of the best spectacles of the last years, in terms of population….Tens and tens of trees were full with clusters – more than 50 trees covered– on top, by one side, by the middle, with heavy clusters or lighter clusters hanging…It was a wonderful spectacle,” wrote Romero.

Edith Smith, a commercial butterfly breeder and owner/founder of Shady Oak Butterfly Farm in Florida, expressed exasperation about the negative headlines in an email to the Association for Butterflies email list, a listserv for commercial and hobbyist butterfly breeders. “Am I the only one who wishes positive information about Monarch butterflies was shared at times?,” wrote Smith. “Numbers are down by 27 percent from last year. BUT they are UP from the year before….We’re up over four times the lowest we had. That is still GOOD news.”

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Weather extremes create quandary: what to do with late season butterflies?

The first week of 2017 can be likened to the worst of a bad relationship, vacillating between hot and cold so drastically we’re left perplexed. What to wear–sweater and long johns or shorts and a t-shirt?

Mikey the Monarch

San Antonio Mayor’s Mikey the Monarch hatched and was released at the San Antonio Zoo flighthouse on January 5. The temperature outside was in the 40s. Photo courtesy San Antonio Zoo

Imagine what that’s like for butterflies and other cold-blooded creatures.The first six days of San Antonio’s New Year had temperatures swinging from 29 to 81.

Such drama will continue. With cozy pockets of our urban heat islands creating perfect microclimates for year-round host plants, Monarchs, Queens Gulf fritillaries and others continue to lay their eggs irrespective of the seasons. The eggs will hatch, morph into caterpillars which some of us won’t be able to resist bringing inside and raising to the chrysalis stage. Then on a mild winter day–like last Tuesday or Thursday when temperatures climbed to 81 and 71 respectively–a glorious, perfect butterfly will hatch.

Then what? It’s 29 degrees outside.

Generally, butterflies won’t fly when temperatures are less than 55 or 60 degrees. And after spending weeks fostering an egg, then a caterpillar, and finally a chrysalis to the point of becoming a butterfly, the idea of unleashing it into a cold, wintry wind seems brutally unacceptable.

“Cold weather does a number on all insects. That’s a given,” said entomologist MIke Quinn, who runs the über helpful insect education website Texasento.net.

I’ve stopped raising butterflies at home in the winter because the stress of having to deal with these late season beauties cancels much of the fun for me. After December 1, I let Nature do her thing.

But I get that many can’t resist having colorful creatures lilting around your home or office providing their unique charms in the dead of winter.

Our butterfly friendly Mayor Ivy Taylor hatched Mikey the Monarch on January 5. Mikey got a free ride to the San Antonio Zoo to live out the rest of his life in the climate controlled flighthouse filled with coddled milkweed and other plants the Zoo keeps in its greenhouse. Education manager Laurie Brown said Mikey may be released to the elements if temperatures warm up.

Our friend, District 1 City Councilman and Monarch Butterfly and Pollinator Festival docent Roberto Treviño got lucky with a milkweed plant we gave him in November. The gift included one fifth star Monarch caterpillar and one Monarch chrysalis. Yet Treviño ended up with four extra butterflies-in-progress. Unbeknownst to us, several eggs were hiding in the milkweed plant.

Councilman Treviño tagged and released the Monarchs, which hatched around Thanksgiving. He’s hatched several Queens since, the last of which emerged this week  on a chilly winter day. His strategy? Hold the butterflies indoors until the weather warms up, then release them on the San Antonio River.

San Antonio City Councilman Roberto Treviño’s Thanksgiving Monarch. It was a boy. Photo courtesy Roberto Treviño

This Queen hatched in January in Treviño’s office. Check out the frass on the keyboard and around the computer. Photo courtesy Roberto Treviño

Caterpillar found its way to the computer plug to make its chrysalis. Hey, it’s warm back there! Photo courtesy Roberto Treviño

Is San Antonio a butterfly friendly city or what? Photo courtesy of Roberto Treviño

So for those who can’t resist fostering butterflies in winter, here’s some tips for dealing with late season butterflies, recast from a 2013 blogpost.

Entomologist Quinn suggests if you bring in found caterpillars, eggs or chrysalises, park them on a screened porch or cool garage to slow down their development in anticipation of warmer weather. Quinn points out that some butterflies overwinter in the chrysalis stage (like Swallowtails) while others, like Monarchs, overwinter in the adult, butterfly stage.

If you have adult butterflies and want to hold them for warmer days, Connie Hodson, a butterfly breeder and owner of Flutterby Gardens in Tampa Bay, Florida recommends sponges–scrubbers, actually–soaked in grape- or punch-flavored Gatorade laid out in shallow dishes in a butterfly cage.

Queens on sponges

Baby, it’s cold outside: soak scrubbers in Gatorade so butterflies can fuel up for when the weather turns. Photo by Monika Maeckle

Since butterflies taste with their feet, you have to set them on the sponge so they can “taste” the fake nectar, whetting their appetite. At that point, they’ll extend their long proboscis and slurp some fuel to power their flight.

You can try bringing in cut or potted flowers and laying out a spread of overripe fruit in the butterfly cage. Cotton balls soaked in sugar-water and apple juice are

Queens in the cage

Queens were not too keen on my offerings of fruit, flowers and sugar water. Photo by Monika Maeckle

another option. I’ve had mixed success with this. Sometimes the butterflies accept the smorgasbord, but mostly not.

Butterfly breeder Barbara Dorf of Big Tree Butterflies in Rockport likes to use tried-and-true hummingbird nectar–four parts water to one part sugar. She said a shallow dish or the top of a plastic container work well as a feeding station.  Lightly misting the sides of the cage with water helps the butterflies stay hydrated. “All you can do is keep them til a good warm day,” said Dorf.

Hodson pointed out that recently hatched butterflies are not hungry for the first 24 – 48 hours, so if sun is in tomorrow’s forecast, just wait. If days pass and the weather hasn’t turned, continue offering fresh nectar surrogates and keep spritzing the netting of the cage.

If the butterflies resist the sponge or scrubber, Hodson suggested taking a Q-tip, dipping it in the Gatorade and gently touching the creatures’ proboscis so they get the hang of it.

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Q & A: Dr. Anurag Agrawal challenges Monarch butterfly conservation conventional wisdom

Dr. Anurag Agrawal has a bit of a contrarian streak. Named the recipient of the prestigious MacArthur Ecology Award earlier this year, he was lauded for “opening up new research themes” and continuing “to push the envelope using novel approaches” to science, teaching and building community.

Anurag Agrawal by Frank DiMeo

Dr. Anurag Agrawal –PHoto by Frank DiMeo

Take a paper Agrawal and a team of researchers published in April, for example. Titled “Linking the continental migratory cycle of the monarch butterfly to understand its population decline,” Agrawal dared to suggest that the intense focus on milkweed in Monarch butterfly restoration efforts might be misplaced. Solutions that address habitat fragmentation and increasing the availability of late season nectar plants should receive more attention, he proposed.

Born in Allentown, Pennsylvania, Agrawal currently serves as Professor of Ecology and Evolutionary Sciences and Faculty Fellow at the Atkinson School of a Sustainable Future at Cornell University. He’s married to fellow Cornell professor Dr. Jennifer Thaler, an insect ecologist, and the couple have two children, Anna and Jasper. Agrawal attributes his initial interest in science and plants to his mother’s intense love of vegetable gardening.

“Planting milkweed is probably not a bad thing to do but it’s not going to increase populations or save them from demise,” said Dr. Agrawal in a nine-minute video released in conjunction with the paper.

The paper rocked the “Monarchy” as he calls the scientific and citizen science communities devoted to the migrating insects in a soon-to-be published book, Milkweed and Monarchs: A Migrating Butterfly, a Poisonous Plant, and their Remarkable Story of Coevolution. The book will be available in April 2017. If all 296 pages are as readable and interesting as the first chapter, which you can read for free at the Princeton University Press website, Agrawal will have a butterfly bestseller on his hands.

Milkweed and Monarchs:

Milkweed and Monarchs, available in April 2017.  Dr. Anurag Agrawal’s soon-to-be-published book, details how the Monarch and milkweed plants have coevolved. –Courtesy photo

Agrawal has called the decline of the Monarch butterfly migration a “very gnarly problem,”  and consistently gives kudos to citizen scientists for contributing to our understanding of them. He often cites a need to “get the science right.”

That sounds like an honorable goal. Let’s hear more from Agrawal, below.

Q: Did you get a lot of flack for your contrarian view on the priority placed on milkweed in Monarch restoration efforts?

Agrawal: I did get a lot of flack.  And I would say that it was pretty interesting, too, because a substantial amount of the flack was off-the-record.

We had sent the manuscript to several Monarch researchers and many of their comments substantially improved the study. But there was a lot of pushback from very prominent research before we got it published. They were asking, ‘Do you want to be the person that derails Monarch conservation? You will appear to be in bed with Monsanto.’

It’s nice to think about science as a fact-based enterprise, but I was really surprised at the extent to which there was a strong agenda and some folks were not open to alternate interpretations of the data and the conventional wisdom.

I was anxious to see what would happen once the paper was published. And I was glad to see that when some of the senior Monarch researchers were asked, they said they didn’t agree–but they were far less bold in their public disagreement or criticism of the work.

My hope is that the study contributes a little to a change in perspective. Any good scientist would agree there are many factors and many causes that contribute to Monarch decline and getting the science right is critical to having a positive impact.

Q: Is it not the nature of the evolutionary cycle for creatures to STOP migrating if they can secure the food and reproductive resources they need locally?

img_2433

Predators like the Tachinid fly serve the evolutionary purpose of keeping the Monarch population in check. Here, Tachinid larvae next to dead Monarch caterpillar. Photo by Monika Maeckle

Agrawal: For Monarchs, it’s known that the ancestral populations are migratory but that there are nonmigratory populations in Florida, Spain, Hawaii and elsewhere. Some new populations will evolve to be non-migratory, including some non-migratory populations in Mexico.

Scientists believe that migration evolves to take advantage of a large un-utilized resource in some seasons. For example, movement north from Mexico and the southern U.S. in spring evolved to take advantage of abundant milkweeds in the Midwest and Northeastern USA.

Migration is certainly an evolvable trait. In many of the articles I’ve read, almost everyone agrees Monarchs are not under any threat to go extinct; but the migratory phenomenon, one of the most spectacular in the world, may be at risk of going extinct.

Q: Is it arrogant of us to work to perpetuate the Monarch migration for the sake of our joy and fascination of witnessing the natural spectacle? What would the butterflies think if they had the option to reproduce and feed locally rather than migrate thousands of miles?

You’ve asked a really good question: is it arrogant for us to expect the migration to continue forever? The reason people worry about its loss is that we have to ask, to what extent is that loss driven by human consumption of the planet?

The world is changing on its own, organisms are evolved creatures and go extinct all the time; the pace of that extinction is much more rapid in recent years than in the pre-industrial past. It has been likened to the pace of mass extinctions caused by events like asteroids hitting the planet. If that’s the case, and we have some control over it, then my answer is quite different than if the decline is due to “natural causes.”

Q. What is your view on Tropical milkweed, Asclepias curassavica, and advice from many scientists to chop it down in the late summer and early fall? What about other milkweeds that continue growing through the season in warm climates?

Agrawal:  We just don’t really know. That hits on a key issue: what causes the break in reproductive cycle–is it the presence of milkweed flowers in general, or is it something specific to Tropical milkweed?

Asclepias curassavica, Tropical milkweed, NOT native, but a great Monarch host and nectar plant for all butterflies. Photo by Moniak Maeckle

Asclepias curassavica, Tropical milkweed, NOT native, but a great Monarch host and nectar plant for all butterflies. To plant it or not is not a simple question. Photo by Monika Maeckle

We don’t know all the reproductive cues that affect Monarchs. Scientists discouraging “non-native” milkweeds are sticking with the precautionary principle–i.e., natives are expected to keep monarchs on track to continue their cycle.

What is a gardener to do?  Plant native milkweeds.

Habitat protection is a good thing. But there are a lot of unknowns. During the southern migration we’re just starting to get some sense of what happens in Texas–but we have very little information about what happens for the last 800 miles. That last third in Northern Mexico is when they’re struggling with wing wear, with lack of fuel (nectar), and we have very little data on that leg of the journey.

Q. Do you think that the rearing and release of Monarchs by citizen scientists and enthusiasts is harmful or helpful to the cause?

Agrawal:  It’s not something I have a scientific opinion on. It’s a double-edged sword in some ways… I’m very pro public engagement with the natural world, but I’m personally not that fond of the rear-and-release for the purpose of “helping” a species. It hints of a little bit of arrogance. We’ve created some problems and now we’re going to solve it by just raising them to make up the difference?! That’s not how nature works.

What makes people think that rearing them in cages is going to increase the abundance of the species? Look at the Bald Eagle. It wasn’t rearing them in captivity that saved them; it was improving habitat, understanding where they want to nest that made the difference.

We all desperately want to help, but I’m not sure that getting in the drivers’ seat is the most sensible approach. I would argue from the perspective of environmental education it makes a lot of sense–to be in Nature, to experience it, it’s something we can do.

Q. Are you aware of the recent Monarch zones efforts by folks in Iowa whereby volunteers raise and release Monarchs using an outdoor biotent natural rearing protocol? Is that any different, better or worse than enthusiasts or commercial breeders raising and releasing butterflies?

Agrawal:  Natural is often better. There’s pretty strong evidence that suggests exposure to ultraviolet light kills off some of the parasites and that the natural cues of sunlight will increase the probability of the Monarchs migrating. But in Nature, more than 90% don’t survive!

It’s worrisome to take natural filters out of the life cycle that natural predation provides.
When a seedling in a forest makes it to be an adult tree it’s a one-in-a-million event. It’s the one individual in the snowstorm of acorns that wasn’t eaten by squirrels at the right place at the right time that makes it.

The life of a Monarch is the same, in a way. Of those 400 million butterflies in Mexico, only a fraction made it. For the population to be stable, there’s a biological filtration process that creates resistance to predators. Mass rearing removes that filter.

Q. What is the one most important thing gardeners, citizen scientists and regular folks can do to help pollinators and Monarchs?

Agrawal:  Something they can do is what they don’t do: don’t spray pesticides around their homes. Having a few more weeds around allows some diversity there, which is likely to protect the animals that visit those plants.

The home gardening movement has all kinds of benefits–reduce lawn and reduce consumption.

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Climate Change and the Monarch Butterfly Migration Symposium tackles tough questions

“Each one is a hole in the sky through which we can get a glimpse of heaven”.

–Mississippi wildlife artist Walter Anderson

That was how moderator Dan Goodgame launched our Climate Change and the Monarch Butterfly Migration Symposium October 21 at the Pearl Studio.

Monarch cat on swamp

The “new normal”?  Monarch butterflies continued to reproduce late into the season this year as warm temperatures caused many to break their diapause and lay eggs rather than migrate. Photo by Monika Maeckle

The 89-minute discussion was just one of three events that made San Antonio’s first Monarch Butterfly and Pollinator Festival–three-days of art, science and celebration commemorating our favorite migrating insect, Danaus plexipus–such a success last month.

We share the video of that symposium in its entirety today, thanks to the generous support of the John and Florence Newman Foundation, a San Antonio foundation that invests in progressive initiatives in San Antonio and beyond.newman-logo

Questions raised in the symposium discussion are timely given the recent election and the long, late extremely unusual migration of Monarchs this season. As Thanksgiving approaches, many of us are STILL seeing Monarch butterflies in our gardens and wildscapes; policy questions about how President-elect Trump will address climate change and pollinator advocacy hang in the balance.

The symposium brought together an equal number of scientists and citizen scientists representing all three countries touched by the Monarchs’ North American travels to a sold-out house.

27-credit-artielimmer-texastechuniversity

On the panel: Dr. Katherine Hayhoe, rock star climate change expert from Texas Tech University. Born in Canada, Hayhoe “grew up with Monarchs” and had just returned from a visit to the White House where Leonardo DiCaprio asked her for her autograph.

 

 

Cathy Downs, from Comfort, Texas, works as an education cathyoutreach specialist  for Monarch Watch.

 

 

 

Dr. Cuauhtémoc Saenz RomeroMexican forester Dr. Cuauhtémoc Saenz Romero, of Michoacán, had been visiting Trinity University as a guest professor in ecological sciences; Dr. Saenz Romero studies the Oyamel forest where the Monarchs roost each winter.

 

 

maeckleheadshotMonika Maeckle, of the Texas Butterfly Ranch. That’s me. I was on the panel, but we didn’t plan it that way. At the last minute, our good friend Catalina Trail, founder of the Monarch butterfly roosting sites in 1975, was unable to attend because of a medical condition. I took her place.

The lively discussion touched on everything from the pros and cons of Tropical milkweed Asclepias curassavica, to whether or not “assisted migration,” or moving the Oyamel forest in Mexico where the Monarchs roost 2,000 feet higher in elevation to save it from climate change constitutes “interfering with nature.” Mitchell Hagney of the Rivard Report wrote a great wrap-up of the symposium the day after it happened.

At almost 90 minutes, the video may be a bit long for some. Thus, I have noted what I found to be some of the more interesting points with time stamps so those in a rush can skip to the parts that most interest them.

Two videos are also embedded in this one. Our butterfly friendly San Antonio Mayor Ivy Taylor, whose signature on the National Wildlife Federation’s Mayor’s Monarch Pledge made San Antonio the first Monarch Champion City in the country, recorded a welcome video for the Festival since she was unable to join us because of a previous commitment. That two-minute video can be viewed at minute 2:17, or you can watch it at the bottom of this post.

Our media partners, the Rivard Report, also made a lovely video with footage taken along the Llano River during peak migration to illustrate a story covering the Festival. That video can be viewed at 4:22.

If you want to skip all that and go straight to the discussion, fast forward to 7:30. Other notes/highlights are noted below.

*                   *                 *                *                       *               *               *

2:17 Mayor Taylor’s Welcome Video. “I can’t think of a better symbol of the bonds we share as people and as nations than the Monarch Butterfly,” says San Antonio Mayor Ivy Taylor.

4:22 Rivard Report video.

7:30 Moderator Dan Goodgame introduces panelists.

10:25 Video “Get Well Card” for Catalina Trail, from audience.

11:27 Maeckle explains how she came to know Catalina Trail.

16:01 Cathy Downs offers a state-of-the-union of the Monarch butterfly population.

19:27 Dr. Hayhoe discusses how climate change works as a “threat multiplier” to the Monarch butterfly migration and many other issues.

21:06 Dr. Saenz Romero explains how the unique ecosystem of the Oyamel fir forests in Mexico serves as a blanket for the Monarchs’ in the winter, raising the temperature up to 10 degrees under the forest canopy, keeping the Monarchs from freezing.

oyamel drought

Dr. Saenz Romero discussed how drought and extreme weather has been tough on the Oyamel trees. They can’t get enough water from the soil during the dry season to keep the tree tops from dying. Photo by Dr. Cuauhtémoc Saenz Romero

28:35 Dr. Saenz Romero introduces the “radical” idea of moving the forest.   “I may be crucified by some ecologists,” he says.

“So when you plant Oyamel at higher altitudes than it exists today, we have to move the population higher. Then we have to hope, some say pray, that the Monarchs will change the location of their overwintering sites. We don’t know if it will happen. As you know, the generation that got to Mexico had never been to Mexico.”

“By 2090 there will not be a single square kilometer of climate that is good for the trees where the Monarchs go for over wintering.” –Dr. Saenz Romero

32:30 Dr. Saenz Romero bemoans the challenges of moving the forest higher, noting that even though “there’s no soil” above the tree line, that  has not stopped avocado growers from trucking in soil to Michoacán to grow avocados “for your Superbowl.”

35:05 Goodgame poses the question: will the butterflies follow the forest up the mountain if the Oyamel forest is moved? Downs tackles the question.

36:43 Hayhoe chimes in that indeed the butterflies could adapt—if they have time, “So after the last ice age there was a huge warming of the planet. That warming happened over 10-50 times longer than what we are seeing today.”

“If the climate changes more slowly, will the butterflies adapt? I think the answer is, yes. Without a doubt. I think the question really is: can they adapt this quickly without help? And it isn’t just the butterflies.”–Dr. Hayhoe

39:30 Cathy Downs suggests what we can do to mitigate the damage of climate change, including planting milkweeds and late season nectar plants.

43:30 Downs and Maeckle discuss the odd, late Monarch migration this fall and how Monarchs are more frequently breeding this season. “They aren’t supposed to do that, they aren’t reading the book!” says Downs. “They are supposed to be in diapause.”

44:00 Maeckle brings up the Tropical milkweed debate—the question of what are native plants in the Monarch world. “If it’s ok to move a forest out of its native zone, why not a host plant?”

45:39 Saenz attempts to answer the question.

48:19 Dr. Hayhoe offers ideas about how to talk about climate change. “The reason why we care about a changing climate is because it takes something that we already care about, that we’re already concerned about, and it puts that extra straw on the camel’s back.” she says. “So in the case of the butterflies, there are already many reasons to be concerned.”

“What is climate change doing to the butterflies?” It’s doing a few different things. It is actually changing their phenology—what does that mean? It means when they breed and when they migrate. We just heard first-hand witnesses of how things are changing, and they’re changing because the warm temperatures are throwing off the butterflies’ internal calendars.” –Dr. Hayhoe

50:50 Hayhoe offers that we need to build resilience and wean ourselves from fossil fuels. She expresses hopefulness tied to the Paris Climate Change Treaty.

54:32 Saenz answers Goodgame’s question about how ecotourism is effecting the roosting sites—hurting or helping?

“Tourism is very positive at overwintering sites, because there is a very severe restriction to cut trees today, because it’s a biosphere reserve in the core area, so nearly the only income alternative to cut trees is to have ecotourism.”–Dr. Saenz Romero

56:10 Saenz Romero expresses pessimism about the voluntary enforcement of the Paris Climate Treaty, as Mexico begins oil drilling in the ocean and continues to import oil from Australia.

58:44 Goodgame introduces the issue of the possible copper mine at the Monarch roosting sites in Mexico.

1:01:15 Question from the audience: Should the mastodons still be alive today?

1:03:55 Goodgame follows up: Is the issue that the butterfly will go extinct, or that it just stops migrating?

Maeckle answers with a question: why do insects migrate? For shelter, for host plant, to reproduce. And if the Monarch butterfly can have local milkweed and mates here in San Antonio or Houston or Florida, why should they migrate? Why would they migrate?

“Is it a vanity for us as human beings for us to expect this insect to make that journey so we can be marveled, so we can appreciate it? And what would the butterfly say if we could interview the butterfly?”–Maeckle

1:05:52 Downs debates the pros and cons of migratory vs. local Monarch butterfly populations. “Personally, I think it’s important and I’m all for the vanity of that.”

1:13:56 What are the impacts of pesticide use?

1:16:08 Is Tropical milkweed good or not?

1:19.08 Do the two or three milkweeds in my yard make a difference?

1:19:58 Are we preventing adaptation by interfering with nature?

1:20:54 What other species of trees are part of the forests where the Monarchs roost? What is the reforestation plan for the Oyamel forest?

1:23:00 What is the forest going to look like in 50 years? And is there a possibility that the Monarchs would roost there on other species?

1:26:46 How will climate change impact predation pressure on Monarchs?

thanks

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Climate change expert Dr. Katherine Hayhoe at TribuneFest: “Hopelessness is hopeless”

Dr. Katherine Hayhoe, one of the foremost experts in the world on climate change, appeared at the Texas Tribune Festival this weekend in a one-on-one interview with Neena Satija,  the news organization’s environmental and investigative reporter.

27-credit-artielimmer-texastechuniversity

Climate change expert Dr. Katherine Hayhoe will join us at our Climate Change and the Monarch Butterfly Migration Symposium in San Antonio October 21 -Photo by Artie LImmer, Texas Tech University

Since Dr. Hayhoe will be joining us at our Monarch Butterfly and Pollinator Festival October 20 -22 as a speaker at our climate change symposium, I thought I’d sit in on the session to get a preview of what we might hear from her next month. Tickets available here.

Hayhoe did not disappoint. But first, a bit of background.

Born in Ontario, Canada, she “grew up with Monarch butterflies,” she told me after her appearance. She was raised as an evangelical Christian and climate skeptic.

butterflyfest_300x600Now, as an atmospheric scientist, Hayhoe serves as an associate professor and director of the Climate Science Center at Texas Tech University with a B.Sc. in Physics from the University of Toronto and an M.S. and Ph.D. in Atmospheric Science from the University of Illinois. She devotes herself to developing and applying climate projections to understand what climate change means for people and the natural environment. As a lead author for the Second and Third U.S. National Climate Assessments, she has conducted climate impact studies for a broad cross-section of organizations, cities and regions, from Boston to Texas to California.

“I am also the founder and CEO of ATMOS Research, where we bridge the gap between scientists and stakeholders to provide relevant, state-of-the-art information on how climate change will affect our lives,” Hayhoe states on her website.

This bridge building becomes most interesting when Hayhoe taps into her identity as an evangelical Christian married to a pastor–not the typical profile of a climate change activist. She and her husband Andrew Farley, a professor of applied linguistics and best-selling author, wrote A Climate for Change: Global Warming Facts for Faith-Based Decisions, a book that untangles the complex science of climate change while tackling long-held misconceptions.

This defying of the stereotype gives Hayhoe a unique ability to talk about climate change in a way people can hear and understand.

Satija Hayhoe

Neena Satija interviews Dr. Katherine Hayhoe at the Texas Tribune Festival. Photo by Monika Maeckle

Referring to the “earth’s fever,” on Saturday at Calhoun Hall on the University of Texas at Austin campus, she pointed out how the values that drive people to do things big and small to combat client change are the same values upon which every major religion in the world are founded–taking responsibility, caring about the future our children will face, and caring for the poor, for example.

“Hopelessness as a policy is hopeless,” Hayhoe said. “Hope is what keeps us going as humans.”

She added that the poor and the vulnerable are the human populations most effected by climate change. Native Americans in Alaska and Louisiana have been displaced and are the first climate change refugees “because their land is sinking,” into the rising oceans, she said.

climate change hayhoe book

Hayhoe’s book, coauhored with her husband Dr. Andrew Farley, unravels misconceptions about climate change. Courtesy photo

But Hayhoe’s primary message was one of hope. She cited the progress and actions cities are taking across the country to fight climate change–planting more trees, reducing pavement, concrete and other impervious cover, creating green roofs to help reduce temperatures in urban heat islands.

She praised British Colombia’s carbon fee dividend program–whereby companies and individuals charge a fee for greenhouse gas emissions, which are then refunded to taxpayers as a dividend. “China’s 2015 coal emissions dropped for the first time. They have more wind and solar than anyone,” she said.

She encouraged those advocating to combat climate change to “leave the science behind” and talk about something that touches people’s hearts.

“To talk to people about climate change, don’t start with the science, talk about something that is personal to them,” said Hayhoe. “We must be able to connect where our heart is, not just where our head is.”

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Mexico, Canada and Obama recommit to conserving Monarch butterfly migration

President Barack Obama, President Enrique Peña Nieto of Mexico and Prime Minister Justin Trudeau of Canada met in Ottawa, Canada, on Wednesday and reconfirmed their commitment to preserve the Monarch butterfly migration.

President Barack Obama and Prime Minister Justin Trudeau of Canada greet President Enrique Peña Nieto of Mexico upon arrival for the North American Leaders' Summit at the National Gallery of Canada in Ottawa, Canada, June 29, 2016. (Official White House Photo by Lawrence Jackson)

President Enrique Peña Nieto of Mexico, President Justin Trudeau of Canada and U.S. President Barack Obama met in Ottawa, Canada this week and talked climate change, clean energy and Monarch butterflies. (Official White House Photo by Lawrence Jackson)

Three Amigos summit touches on climate change, terrorists and butterflies,” read the headline in the Toronto Sun.

Amidst discussions of clean energy and climate change cooperation and comments that compared Donald Trump to Hitler, the “Tres Amigos” used the Monarch butterfly migration as an example of the three countries’ inherent connectedness in a time of political isolationism.

President Peña Nieto of Mexico mentioned in remarks that Monarch butterflies “no longer need visas” and used the migrating insects as an example of globalism. “This is a species that, in its pilgrimage, we can see how our countries are intertwined,” said Peña Nieto.

President Obama called Monarchs “spectacular.”

“I love the story of the Monarch butterflies,” he said. “They’re not just any species — they are spectacular and we want to make sure that our children, our grandchildren can see them as well.”

Monarch butterflies on the Llano River

President Peña Nieto of Mexico suggested the Monarch migration symbolizes how our three countries are intertwined. Photo by Veronica Prida

By the end of the day, the North American leaders had jointly issued “The North American Climate, Clean Energy and Environment Partnership Action Plan.”

In a section labeled “Conserve the Monarch butterfly and its habitat,” the North American leaders committed to:

  • Continue to address habitat loss and degradation of the Monarch butterfly and other pollinators.
  • Promote sufficient breeding, staging, migration, and overwintering habitat and assure it is made available domestically to support the 2020 Eastern Monarch population target represented by its occupation of six hectares of overwintering habitat in Mexico.
  • Continue collaborating through the Tri-national Monarch Science Partnership to coordinate priority research, monitoring, information sharing, and tools development.
President BArack Obama

Thanks, Obama! We think Monarchs are “spectacular,” too.  Courtesy photo

The NAFTA Presidents’ reunion came 26 months after they first gathered in Toluca, Mexico and agreed to form a task force to study the situation and “ensure the conservation of the Monarch butterfly.”

In the two years and four months since that declaration, much has changed.

Here in the United States, President Obama ordered up a National Pollinator Strategy upon returning from that trip. When the 58-page document was released a year later in May of 2015, it created a public focus on the plight of pollinators, the Monarch butterfly migration in particular.  Millions of dollars in research grants, educational programs and government supported initiatives began pouring into the cause of restoring pollinator habitat and educating the public, including the National Wildlife Federation’s Mayor’s Monarch Pledge, which encourages communities along the IH-35 corridor to increase pollinator habitat for Monarchs and other species.

Since the 2014 meeting, the Monarch butterfly population has climbed significantly, tripling this last season. But then climate change dealt the recovery a brutal blow with an unseasonable freeze in March, sweeping through the Oyamel forest where the butterflies roost, killing millions of the migrating butterflies and wrecking the forest “blanket” that ensures their warmth in the winter. Scientists are still assessing the damage. Some projections suggest up to 100 million butterflies were killed.

The scene at Chincua two weeks after the storm. Photo by Dr. Isabel Ramíro

A freak snowstorm in March killed millions of Monarch butterflies this year, just as they were beginning their journey north.Photo by Dr. Isabel Ramíro

Such uncertainty makes a continued North American cooperative effort all the more welcome.

From the Whitehouse press office:

“We reaffirm our commitment to work collaboratively to achieve our long term goal of conserving North America’s Monarch migratory phenomena and to ensure that sufficient habitat is available to support the 2020 target for the eastern Monarch population.

Read the White House press release.

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Scientists try to assess Monarch butterfly mortality after Mexican freeze

Scientists have been scrambling  to assess the mortality of the roosting Monarch butterfly population in Michoacán, Mexico, following a freak March 11 winter snowstorm that dropped temperatures to sub freezing and included wind gusts up to 50 miles per hour in the butterflies’ ancestral roosting sites.  For now, the estimates of how much of the migrating Monarch butterfly population perished are at best an educated guess.

The scene at Chincua two weeks after the storm. Photo by Dr. Isabel Ramíro

The scene at Chincua the day after the storm.   Photo by Dr. Isabel Ramírez

 

“I have no new information. We are ‘in limbo,’” said Dr. Chip Taylor, founder of Monarch Watch, the citizen science organization based at the University of Kansas that tags the butterflies each fall to track their migration.

Dr. Lincoln Brower has been working long distance from his home in Sweet Briar, Virginia, with a team of scientists on the ground in the 10,000-foot-tall plus mountains northwest of Mexico City where the butterflies roost each fall.  They’ve been gathering data, reviewing climatology information, making observations, and reviewing photos and historical accounts of a previous freeze in 2002.

“It’s been difficult and there are conflicting reports as you know,” said Dr. Brower via email, referring to Mexican tourism officials downplaying the severity of the situation. Soon after news of the storm broke, Mexican officials claimed that only 3% of the butterflies had been affected–about 1.5 million of the estimated 200 million roosting.

“The climate data we have suggest about 50% mortality in Chincua but observations suggest that Rosario was hit harder,” said Brower, referring to the El Rosario sanctuary, the preserve most often visited by tourists. The 50% number would mean 100 million butterflies took the hit–which still leaves us up over last year, just a disappointing and devastating turn of events, if true.

El Rosario Preserve in Michoacán. Photo by Monika Maeckle

El Rosario Preserve in Michoacán. Photo by Monika Maeckle

Dr. Cuatémoc Sáenz Romero, a forester who studies the Oyamel forest and is promoting an initiative to move it higher in elevation to save it from climate change, thus guaranteeing the Monarchs a future winter roost, said he visited the sanctuaries two weeks after the storm. “Except for some trees fallen, I did not see dramatic damages,” he said.

Many of us are wondering how many of the butterflies had already left the colony when the storm hit on March 11.  Typically the first and second week in March are when the Monarchs bust off the Oyamel trees in response to warmer temperatures and begin their journey north.  We start to see them moving into South Texas as they search for milkweed on which to lay the first generation of eggs in the multi-generation migration. Some Monarchs have definitely made it to San Antonio and South Texas as we are witnessing and hearing about first-of-season sightings and finding eggs on local milkweeds.

monarch eggs on milkweed

Who’s got Monarch eggs? We do in San Antonio. At least SOME Monarchs escaped the storm. Photo by Monika Maeckle

The question of how many Monarchs departed before the storm hit may be rhetorical, according to one scientist.

“Perhaps that doesn’t even matter given how widespread this storm was,” said Monarch and migration scholar Dr. Tyler Flockhart of the University of Guelph in Ontario.  Flockhart said that according to weather data, the winds were so strong that temperatures inside and outside the forest were pretty much the same, suggesting the “butterflies would have been exposed to very cold temperatures.”

Scientists consider the forest canopy as an insulation blanket.  As climate change and illegal logging conspire to undermine the forest in the roosting preserves, the unique ecosystem of moisture, temperature and protection from the elements becomes threatened.   Several scientists expressed more concern about the huge trees that had been taken by the storm than the mortality of the butterflies, since it will be extremely challenging to recreate the forest canopy in the short-term.

Meanwhile, a study conducted by the Monarch Conservation Science Partnership and released in the journal Scientific Reports March 21 found that the Monarch migration has an 11 to 57 percent chance of facing “quasi-extinction” in the next 20 years.

Dr. John Pleasants, an Iowa State University researcher who participated in the study, defined quasi-extinction to mean that not enough individual Monarch butterflies would exist to continue their migratory patterns.  The migration would collapse and the population would likely not recover.  That doesn’t mean there will no longer be Monarch butterflies;  it does suggest the phenomenon of the unique Monarch butterfly migration would cease to exist if the population falls to even more perilous levels.

We should have more definitive information in the next few weeks as the scientists review the collected data.  Stay tuned and keep those fingers crossed.

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Guidance on milkweed management confuses butterfly gardeners

Confusion reigns for gardeners and Monarch butterfly enthusiasts trying to “do the right thing” managing their late season milkweed, the host plant of Monarch butterflies.

monarch laying eggs on swamp milkweed

Monarch laying eggs on Swamp milkweed, Asclepias incarnata, in downtown San Antonio November 15, 2015. Photo by Monika Mae

For the last few years, scientists like doctoral student Dara Satterfield and Dr. Sonia Altizer of the University of Georgia as well as renown Monarch scientist Dr. Lincoln Brower have recommended slashing Tropical milkweed, Aslcepias curassavica, to the ground late in the season.  Studies suggest that the year-round availability of Tropical milkweed makes Monarchs more prone to contracting Ophryocystis elektroscirrha, a debilitating protozoan parasite commonly known in Monarch butterfly circles as OE.

Until recently, Tropical milkweed, technically nonnative, has been the only host plant available for butterfly gardeners hoping to lure the migrating butterflies to their yards.  The reliable bloomer will thrive year-round in warmer and coastal climates, especially in Texas and Florida.  Scientists believe this year-round availability creates a hotbed of nasty OE spores and spreads the disease.  Its presence can also encourage Monarch butterflies to break their diapause–or temporarily suspended non reproductive state–and lay eggs, thus unable to complete their migration to Mexico.

No doubt about it: Monarch caterpillars LOVE Tropical milkweed. Photo taken 11/24/2015 by Monika Maeckle

No doubt about it: Monarch caterpillars LOVE Tropical milkweed. Photo taken 11/24/2015 by Monika Maeckle

But now, for the first time ever, native milkweeds are more available.  And judging from the government funding pouring in to milkweed cultivation and the valiant Monarch butterfly habitat conservation effort, even MORE milkweeds will be coming to market soon.  Gardeners will soon have choices beyond Tropical milkweed.

“Plant only species of milkweed that are native to your region, whenever possible.”

That’s what the Monarch Joint Venture OE Fact sheet advises pollinator gardeners like me and you.

We did that.  And like good stewards, we’ve been cutting Tropical milkweed to the ground late in the season.

But guess what?  Those native milkweeds, which have recently become available because of all the attention on Monarch habitat restoration, are thriving late in the season, too.

Egg on Texana

Egg found on Texana milkweed, Aslcepias texana, 11/19/2015. Not sure if it’s a Queen or monarch (and it hasn’t hatched yet.)  Photo by Monika Maeckle

In my yard right now, for example, I have

  • Asclepias texana, Texana milkweed
  • Asclepias incarnata, Swamp milkweed
  • Aslepias curassavica Tropical milkweed
  • Aslcepias tuberosa Butterfly weed
  • Asclepias oenotheroides, Zizotes milkweed
  • Matelea reticulata, Pearl Milkweed vine.

I sought out these various milkweeds at native plant sales, the Ladybird Johnson Wildflower Center, from our family’s Llano River ranch.  I also traded seeds with other pollinator fans, friends and butterfly breeders. At this moment, all but those I’ve cut back (tuberosa and curassavica) still flaunt green foliage, days before Thanksgiving.

Should I cut these native milkweeds to the ground as well?

The theory of OE spores building up over the season, possibly infecting migrating Monarchs would seem to hold true for other milkweeds available late in the year, not just Tropical milkweed.

Right?

“You’re right that it’s less about the plant itself and more about the seasonality of the plant,” wrote Satterfield via email.  “Any plant that grows 365 days a year in the southern U.S. and supports Monarchs year-round could lead to high levels of disease, as we understand it.”

Swamp milkweed seed pod

Drawback to cutting back native milkweeds: we then can’t harvest the seedpods. Photo by Monika Maeckle

“My personal leaning is that if the species are native, they don’t need to be cut back on a regular basis,” said Dr. Altizer via email.  “Any natives that routinely remain in lush green foliage into the fall and winter are likely going to be rare species, or it will be a rare year when this happens, whereas with the Tropical milkweed, these commonly remain in green foliage until they are hit by a hard frost or cut back.”

Dr. Lincoln Brower, always the purist, suggests even cutting late season nectar plants back–if they are growing in close proximity to Tropical milkweed.

“I have given some thought to your question of whether nectar sources might accumulate OE spores,” wrote Dr. Brower via email.  “I think the answer to this is one of probability and proximity to curassavica [Tropical milkweed]. I think that nectar sources are so diverse and abundant in the natural environment that the probability of Monarchs infecting the plants with spores is very small. …unless the nectar plant is growing adjacent to curassavica. Again, yank it out.”

Confused?  You’re not the only one.

Mary Kennedy, volunteer at the Monarch Larvae Monitoring Project

Mary Kennedy, volunteer at the Monarch Larvae Monitoring Project

Mary Kennedy, a longtime Monarch Larvae Monitoring Project volunteer and trainer said she is no longer going to advise folks to cut back their Tropical milkweed. “If milkweed is on the ground late in the season, I don’t see why it makes any difference what species it is,” said Kennedy, a former science teacher. “Grow up kids, and make your own decisions.”

One drawback to cutting milkweeds back late in the season is that we then are unable to harvest the seeds. I cut back a patch of Swamp milkweed in August as it was riddled with aphids and gangly.  The plants failed to produce any more flowers; thus, no seeds have been harvested from that patch to propagate future native milkweeds.

Satterfield insisted that the scientists’ statements are “still correct and not mutually exclusive.”

Swamp milkweed in the "wild" of the Llano River, 11/21/2015. Photo by Monika Maeckle

Swamp milkweed in the “wild” of the Llano River, 11/21/2015. Photo by Monika Maeckle

“Our research suggests that milkweeds that support Monarch breeding year-round in the U.S. could put Monarchs at higher risk of disease. The milkweeds enabling these non-migratory Monarchs are exotic species, like Tropical milkweed and Family Jewels milkweed. We are not aware of any native species supporting large numbers of Monarch caterpillars during the winter in the Gulf states. So, we do not have any scientific support right now that says we should cut back native milkweeds.”

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Late season Monarch butterflies create gardening quandary

It’s mid November and Monarch butterflies continue to visit my San Antonio pollinator garden.  Lighting on Cowpen daisy, Duranta, Gregg’s Purple mist flower and several kinds of milkweed, the butterflies have extended their visits long past their usual late October stay.

Monarch on duranta

Nov. 12,. 2015: Monarchs still visiting my San Antonio garden, this one on Duranta. Photo by Monika Maeckle

That’s not to say we don’t sometimes have Monarchs visiting this late in the season. We do.  In fact, we’ve had many questions from folks up north about what to do with late hatching Monarchs when the weather turns cold. A previous post addresses that. But I don’t ever recall having this many Monarch butterflies this late, and so consistently.

“Yesterday, I saw hundreds of Monarchs in Austin,” wrote John Barr of Native Cottage Gardens in Austin on November 1 in a post to the DPLEX list, the old school email listserv that reaches about 800 butterfly enthusiasts.  ” I saw more Monarchs in 30 minutes than I’ve seen all year. Bright, fresh, long-winged migrating Monarchs of both sexes.”

Monarchs were even spotted recently as far north as Lake Erie, according to Darlene Burgess of Point Pelee, Leamington, Ontario. “There are still Monarchs being seen in Ontario on Lake Erie’s north shore. This week’s warm temps up to 70° should get them south across the lake,” she wrote November 2 on the DPLEX list.

lateseasonblooms

Late season blooms continue to attract Monarchs and other pollinators to my urban San Antonio garden. Photo by Monika Maeckle

Our friends at the Natural Gardener in Austin, which stocks several kinds of native milkweeds, said they’ve had a steady stream of Monarchs visiting as well. “They LOVE the Duranta,” said Curt Alston, buyer for the organic nursery. Alston added that he has plenty of caterpillars and chyrsalises on the native milkweeds, and that adult Monarchs are still breezing through the aisles.

What gives?

Climate change.  September 2015 was the hottest month in recorded history.  October ranked the fourth hottest.  Overall, 2015 is likely to be the hottest year ever, says the New York Times.

Warmer temps mean extended growing seasons.  Plants that typically wouldn’t thrive when fall arrives will continue to grow and bloom, creating more nectar for migrating Monarchs, and in some cases, host plant.

Increased temperatures also mean that Monarch butterflies will likely break their diapause–that is, their asexual state of resisting reproductive activities so as to conserve energy for migrating to Mexico.   Once Monarchs reproduce, they don’t migrate.

winter breeding map

Breaking diapause increases the chances of more year-round Monarch butterfly colonies. Map via Monarch Joint Venture

“We’ve got to get used to the late Octobers and Novembers as part of our future,” said Dr. Chip Taylor, founder of Monarch Watch, the citizen scientist tagging program operated by the University of Kansas at Lawrence.

Taylor predicts that a larger proportion of these late Monarchs will be unable to maintain their diapause and become reproductive.  “Their hormones work on the basis of temperature.  It’s very delicate and complicated,” he said via phone.  “The warmer it is, the more likely it is the Monarch will not be able to maintain a diapause.”

Hmm.  So where does that leave butterfly gardeners?  Should we encourage egg laying with native or clean Tropical milkweed, or just let all those good eggs go to waste?

curassavica

Tropical milkweed: cut it to the ground in the fall to prevent build-up of OE spores. Photo by Monika Maeckle

Research from scientists like doctoral student Dara Satterfield and Dr. Sonia Altizer out of the University of Georgia indicates that the year-round availability of Tropical milkweed makes Monarchs more prone to contracting Ophryocystis elektroscirrha, a debilitating protozoan parasite commonly known as OE in Monarch butterfly circles.  Since OE spores transfer via physical contact between creatures or the plants on which they rest or eat, having year-round milkweed which is visited repeatedly by Monarchs and other butterflies creates a hotbed of these nasty spores and spreads the disease.

Satterfield, et al, suggest hard-to-find native milkweeds should be planted rather than the technically nonnative Tropical milkweed, which is widely available and easy to grow.  Best practice dictates close management of Tropical milkweed.   Cut it to the ground late in the season so OE spores don’t build up and infect migrating Monarchs.

Cowpen daisy

Cowpen daisy: Monarch and pollinator favorite and blooms into fall. Photo by Monika Maeckle

But what about all the other plants that Monarchs frequent?  In my yard, the native Swamp milkweed continues to thrive and various nectar sources have been repeatedly visited by Monarchs and other butterflies since April.  As the Natural Gardener’s Curt Alston said above, Monarchs are loving the lush, purple bloom of Duranta that laces my fence perimeter.  They also repeatedly visit my golden-yellow, late season Cowpen daisies.

Wouldn’t these plants also host the same debilitating OE spores so closely associated with late season Tropical milkweed after so many return visits from Monarchs?   Should we cut those plants down as well, to avoid infecting visiting flyers?

Scientists, what say you?

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