Monarch Population Status

I’ve been monitoring the reports of returning monarchs quite closely this spring. The pattern of the return this year is similar to that seen in 2006 but more exaggerated, with more monarchs moving into the mid latitudes (35-42N) than in any previous April (see Journey North’s first sighting reports). As I pointed out last spring on our email discussion list and in a text written for our May 2006 email update, such early arrivals at more northerly latitudes are not necessarily a good thing. If these butterflies arrive when the milkweeds are above ground and abundant followed by temperatures that allow for normal development of eggs, larvae and pupae – all is well. But, all isn’t well this year. Monarchs arrived in our area (38.97N) in good numbers on the 10th of April with egg laying noted from the 10th through the 15th with some additional eggs on the 18th and later. Milkweeds were scarce -being found in gardens, burned over areas and the edges of roads. Milkweed sprouts in fields were not up or were hidden beneath grasses and weeds. Unfortunately, the temperatures have been colder than normal and none of the hundreds of milkweed stems I’ve surveyed have shown signs of larval feeding even though most of these plants had eggs at one time. At this writing – 26 April – it appears that most of this early reproduction won’t be successful. If so, moving into the mid latitudes earlier than normal will not contribute substantially to population growth this year. In short, it would have been better had these monarchs laid these eggs further south where temperatures were more favorable for growth and development.

In addition to watching the pattern of the returning butterflies, I monitor other conditions – temperature, rainfall, drought, abundance of fire ants, etc., as they play out each month of the breeding season. As you’ve heard from me before, Texas is key. For the monarchs to have a good year, the conditions in Texas for the first generation have to be favorable. If they are, the population grows, as it did last year. If unfavorable, as they have been in a number of years such as 2004, the population declines. Conditions in Texas this spring have been hot and dry – a significant drought. Milkweeds have been abundant and nectar seems to have been available in most locations but due to high winds and temperatures monarchs just kept moving. The result is that monarchs are not off to a good start and the prospects that the population will rebound in the summer months are getting slimmer each day.

At the end of March, I was saying that the population this coming winter would be no greater than 5 hectares due to conditions in Texas. In contrast, at the end of March in 2010 it was quite clear that the population was going to increase and the only question was by how much; it more than doubled from 1.92 to 4.02. It now appears that the 5-hectare prediction was too optimistic. Four hectares (4.02 last year) is possible but not too likely. If the long-range forecasts for the northern breeding areas are accurate, and they have been recently, the prospect for producing a large monarch population in and north of the corn belt is not great. In fact, the population could drop back to 2009 numbers (1.92 hectares), if the summer is as cold as forecast.

In a week or more – weather permitting – first generation monarchs from Texas should begin migrating through this area to colonize the northern breeding areas. The numbers reaching these northern habitats is largely a function of reproduction in Texas and the weather conditions in May. Reproduction is Texas has yet to play out in numbers, but if past seasons are a good measure, the number moving northward should be less than expected based on the size of the overwintering population. Below normal temperatures are projected for May, which, if true, would limit the number of monarchs reaching the milkweed patches throughout the northern breeding area and ultimately the size of the fall migratory population. While we can hope that the long-range forecasts are wrong, and that reproduction will be higher than I’m envisioning, the prospects – at this date – favor a migration that will result in an overwintering population of 2-4 hectares.

We can’t do anything about the physical conditions that drive the monarch population but we can provide the milkweed and nectar resources they need – PLANT MILKWEED!

Monarch Watch Tag Recovery Database Updated

Nearly 4, 000 records have been added to the Monarch Watch Tag Recovery database, bringing the total number of records to more than 15, 000 for the 1992-2010 monarch tagging seasons.

Approximately 2500 records represent monarchs observed/recovered in the U.S. or Canada and more than 12, 500 records represent monarchs recovered at the overwintering sites in Mexico.

Anyone may search the database via monarchwatch.org/recoveries

Please note that this is very much a work in progress – we working on acquiring the funding necessary to “scrub” the data (clean up any errors) and create more robust applications for searching and data visualization. Also, you will likely notice records with missing data – this is often due to taggers not returning their datasheets at the end of the tagging season. We are in the process of tracking down the missing data and will update the database as we recover the information.

If you would like to help fund this project, please see our Donation page for details about ways to give.

Capturing a Honeybee Swarm (video)

A swarm of several thousand honeybees settled in a tree outside of Monarch Watch HQ on April 11, 2011 – they’re not our bees (at least not the bees we have in our building) so we’re not sure where they came from 🙂

Travelog: Monarchs in Mexico

As you can imagine, seeing the monarchs overwintering in Mexico really leaves an impression on those lucky enough to make the trip. We receive lots of enthusiastic communications about such trips and here is Don and Mary Bernd’s account of of their recent adventure…

We had visited El Rosario several years ago in the dead of winter when none of the Monarchs were moving around. It wasn’t all that much fun seeing them clustered in the trees all trying to save as much energy as they could in the cold temperature.

Since then we read the book “Four Wings and a Prayer” which suggests good times to view the monarchs flitting around getting ready for the long trip back north. We decided to try again this year and had a very different experience.

Just getting to Angangueo, Michoacán was a trick for us since we winter in Oaxaca, Mexico like the Monarchs. We inquired about routes through Mexico City and were discouraged until we learned about a newer freeway that skirts Mexico City to the north. We used this route to reach Michoacán and made the whole trip easily in one day from our home in Oaxaca.

We stayed at Plaza Don Gabino where we were made to feel at home by the owner and staff. The food was delightful and the atmosphere very welcoming.

We went first to the Sierra Chincua Sanctuary and when we learned that the hiking trail was 6 kilometers long, we opted for horses. Thankfully the guides and leaders were considerate of our years and took it easy on the trail. Neither of us fell off, but we were glad to get off once we reached the wintering areas.

We hiked to the places where the Monarchs were clustered in the trees and there was an eerie quietness. Nobody spoke – we just watched as the monarchs would leave the congregation and take flight. We could actually hear them flitting around as they were the only thing moving in that quiet sanctuary.

As we walked into a clearing where the sun poured down through the forest and a spring of water rose to the surface, the area erupted with thousands of Monarchs tanking-up after a long winter’s nap. Every blooming flower had a garland of wings covering it with busy Monarch flitting here or there for more nourishment.

After spending some time in this sanctuary we mounted our steeds once more for the journey back to our car and it was with physical relief that we dismounted and planted our feet on solid ground once more. The horses made it possible for us to view this wonder and we were glad for the experience, but we were also glad it was over and we could put the ride behind us.

The next day we headed the other direction to El Rosario where the clustering monarchs are a bit closer to the end of the road. We climbed the seemingly endless stairways, resting from time to time and were treated to the sight of monarchs flying from flower to flower all along the way. There were so many that they became commonplace before long. We allowed our eyes to feast on the beauty, majesty, and quantity of monarchs on the wing there at El Rosairo.

We returned to our hotel tired, but happy and satisfied. We had finally seen the monarchs in profusion as we had read about – a dream of 20 years had finally been fulfilled.

Upon returning to our home in Oaxaca I discovered that my wallet had been lost somewhere on our trip. Bummer! The horse trail was inches thick in black dust and a black wallet would be lost forever in that area. We contacted the hotel and they had actually recovered the wallet and were willing to send it to us at our home in Oaxaca. It took only a few days until I was in possession of my identity documents once again and this closed the chapter of our personal monarch watch.

Our pictures don’t do the monarchs justice, but our memory will forever be etched with the sight of thousands of monarchs flitting from one blossom to another, making ready for their return flight to breeding grounds in the United States and Canada.

Monarch Caterpillar Dorsal Aorta (video)

serendipity [ser-uhn-dip-i-tee] -noun.
1. an aptitude for making unexpected and fortunate discoveries

Occasionally, there is a little serendipity in the lab. One Friday, a few weeks ago, I noticed an unusual larva, a fourth instar of a “black” larval mutation we are studying. This particular larva was lighter than most and we could see the blood coursing through the dorsal aorta. I said “Let’s get a camera, this is neat!”

In the course of doing the filming, and not doing it well, I kept getting advice from one of our critter crew members Alicia Bigelow, and I soon realized (another bit of serendipity) that Alicia needed to be in charge of the production of video projects that I’ve always wanted to post to Monarch Watch’s YouTube channel. So, here is the first production: the Monarch Caterpillar Dorsal Aorta. In the voice-over I describe the general pattern of blood circulation in insects and arthropods. Chip Taylor | Director, Monarch Watch

Book Review: “Fly, Fly Butterfly”

“Fly, Fly Butterfly” by Diego H. Pedreros Velásquez

Interest in monarch butterflies has grown over the last 15 years. Websites featuring monarchs are now common. Monarchs are the subject of numerous blog postings and periodically the topic of newspaper and magazine articles as well. This interest has also produced an abundance of books about monarchs directed toward parents who might buy them for their children. The quality of these books varies greatly. Some have great artwork and not much of a story, others have a good premise but poor execution and still others are filled with errors – the most common of which is to refer to a chrysalis as a cocoon.

The intent of authors is usually to tell the story of the monarch to inspire a sense of wonder; rarely do authors connect the story to larger issues such as our stewardship of the planet. Most of these stories don’t touch me. I’m jaded, having worked with literally tens of thousands of monarchs and having lent my heavy hand to telling this story myself. So, my emotional reaction to a new book, “Fly, Fly Butterfly” by Diego H. Pedreros Velásquez was a surprise to me.

Mr. Pedreros has written an account of his family’s – and particularly his daughter AmaRa’s – discovery of monarchs and their annual cycle through visits to the Ellwood Main monarch sanctuary in Goleta, California. The family’s increasing awareness of monarchs and the environment that supports them is driven by AmaRa’s curiosity, with the help of an equally curious and devoted father.

The author uses the monarch as a metaphor for how we should face life and connects the fate of monarchs to how humans affect the planet. Excellent photographs by the author of monarchs and wildlife around Goleta are tastefully presented on more than half the book’s pages. The design, layout and artwork in the book capture the sense of wonder and adventure of learning about new things through the eyes of both the child and her father. It’s clear that this book was a labor of love that involved a large and talented team. Perhaps the book’s most unique feature is that it is bilingual, with all the text printed in both English and Spanish, with other languages soon to follow. The writing is clear and direct and it is easy to read and understand the text in both languages. In this age, as we watch our population become increasingly disconnected from the environment that supports them and when it is so hard to get children outside, it is refreshing to have this example of a child connecting spontaneously to the wonders of the natural world.

The book may be purchased with a donation component, whereby 40% of the $20 purchase price may be designated to go to Monarch Watch or another approved organization. For more information on “Fly, Fly Monarch” please visit www.forlymonarch.com and https://meditaliana.org/

Mead’s Milkweed and Monarchs

From time to time the question arises as to whether monarchs can and do use all species of milkweeds in the genus Asclepias or whether there are some that are too toxic or have so much latex that larvae are unable to feed properly and die. There could even be some species that lack the chemistry that allows the larvae to even start feeding. Stated another way, it seems possible that some milkweeds might have become as unpalatable to monarchs as they have to other herbivores. It would be valuable to know the answer to this question but we will have to gather more data on what species females chose to lay eggs upon and whether larvae successfully feed and reach the adult stage on a number of species.

There are 72 species of native milkweeds in the genus Asclepias found in the United States. Monarchs use about 30 of these species as host plants with some regularity. Little is known however about the use of many species, particularly the more than 20 that have limited distributions including a number that are rare and endangered. I live in a county (Douglas County, KS) in which 13 species of Asclepias have been recorded. I know locations for 12 of these within the county and have found monarch eggs and larvae on 9 of the 12 species. Two of the three species without eggs or larvae, A. stenophylla (slim leaf milkweed) and A. amplexicaulis (clasping milkweed), are relatively uncommon in the prairie meadows I’ve visited and I’ve always assumed that the lack of evidence of use by monarchs was just a matter of numbers with monarchs simply laying eggs on the most abundant and apparent species. I also knew that monarchs use A. amplexicaulis as a host in other areas.

I reached a similar conclusion with regard to the third species, the rare and endangered Mead’s milkweed, A. meadii. I’ve actually encountered many more plants of this species than of the previous two but again no monarch larvae on any of these plants. Mead’s milkweed is a poor choice as a host, most plants have 6 rather small leaves, the nodding flower-head, if present, is relatively large but overall it seems unlikely that there is enough foliage on a Mead’s milkweed for a single larvae to complete its development. I know better than to speculate that monarch females are smart enough to avoid plants with insufficient foliage but still I had looked at a lot of these plants (hundreds) over the years with nary an egg or larva sighted. So it was with some surprise that I learned that two biologists, Steve Roels (a graduate student at the University of Kansas) and Dr. Retha Meier (Saint Louis University), who study Mead’s milkweed had observed monarch larvae on these plants. I asked Dr. Meier to write up her observations. Here is her report along with two images. Steve Roels provided a third image.

Mead’s Milkweed and Monarchs
By Dr. Retha Meier

Dr. Peter Bernhardt and I began the first season of a three-year study on the pollination of the threatened, Mead’s milkweed (Asclepias meadii) in May 2010. The population we observed grows in a prairie near Garnett, Kansas. Mead’s milkweed is easily overlooked, even where it is common. Each year a plant produces a single, thin, graceful stem that ends in an umbel made up of 5-14 nodding, greenish-colored flowers. Nectar gushes from the horns of these flowers and measures more than 50% dissolved sugar in some flowers. We also discovered that Mead’s milkweed flowers emit an unusually pleasant and spicy fragrance similar to oil of cloves. Nectar and odor must have attracted the monarchs to the dangling blossoms because we watched on numerous occasions as these insects positioned themselves upside-down to drink. While searching for more Mead’s in this diverse prairie we often found it was easier to just follow monarchs to previously unmarked stems in bloom.

One morning while Dr. Bernhardt was measuring floral nectar he discovered that some monarchs were doing something more than drinking. They were laying eggs. He found small stages of the larvae consuming the flowers including the nectar-rich horns. Only one caterpillar was found per umbel but even an early instar, less than 5 mm in length, was capable of doing a considerable amount of damage as it began feeding on the flowers. As flower consumption continued, the small instar grew into a much larger caterpillar that eventually eliminated all the flowers on the umbel. Here we have an example of a much-loved insect spending a most important part of its life-cycle on an increasingly endangered plant. Monarchs didn’t pollinate Mead’s milkweed on the Kansas prairie. Capture and release procedures showed that their mouth-parts and legs were free of the distinctive pollen packets (pollinaria) of their wildflower host. That honor, we’ve learned, belongs to a few, chunky native bees like the Anthophora abrupta.

Steve Roels added the following observations:

Retha’s observations about monarchs on the Welda are similar to my own. Interestingly, monarch herbivory was extremely common on the Welda this year (I believe I saw caterpillars on 10-15 of the 50 stems I was monitoring) but monarchs have been much less frequent on the KU field station Mead’s the last two years. I’m not sure if the difference is due to different butterfly population levels or that plants are easier to find on the Welda because the vegetation is shorter and less dense, making plants easier to find. When caterpillars are present, they can do a tremendous amount of damage, sometimes completely stripping the stem of leaves and buds. They seem to prefer the buds, or perhaps eggs are more frequently oviposited there, and generally the caterpillars work their way from the top of the plant downwards. However, sometimes I have seen caterpillars present one day and then they are gone a few days later, perhaps shuffling off to find a more suitable host plant or getting picked off by some predator. Monarchs did reduce the Welda Mead’s population’s reproductive output to some extent this year but I suspect Cycnia inopinatus is more of a widespread problem for Mead’s.

As far as I know, no one has done any work on the chemical profile of Mead’s as compared to other milkweeds, which could be relevant for a number of herbivores. I considered pursuing this route, but I have plenty of projects as it is. I do wonder if it has lower levels of toxic compounds than other species because deer herbivory at the field station is extremely high in the early spring and I have never seen any deer damage to A. syriaca and only very rarely, if at all, on A. viridis. Some other milkweeds do suffer from the deer including a dense 8’x4′ patch of A. purpurascens that was completely razed last year at the field station.

Additional references for Mead’s milkweed:
http://plants.usda.gov/java/profile?symbol=ASME
http://www.fws.gov/midwest/endangered/plants/pdf/meads-fnl-rp.pdf

Mexico Travel Advisory

We have received a number of inquiries from people who want to know if it is safe to travel to Mexico, specifically to visit the monarch overwintering colonies near Angangueo (El Rosario and Sierra Chincua), Zitacuaro (Cerro Pelon), and Valle de Bravo (Herrada). Most people know of the conflicts among the drug cartels and between the army and these cartels. Most of the violence associated with these conflicts occurs in the Mexican cities and states bordering the United States but some occurs in the states of Michoacan and Mexico, where the overwintering monarchs reside, and in scattered locations along the Pacific coast. It used to be safe to drive into Mexico from the United States and I’ve done it at least 30 times without incident. However, driving into Mexico is no longer safe and should not be attempted. While most of the violence involves cartel members attacking each other and fighting with federal troops, a number of students and visitors to northern Mexico have been killed.

Tours to the monarch overwintering sites are still accepting applications and if you would like to visit Mexico this winter to see the monarchs, we advise you to join one of the tours rather than renting a car. Foreign tourists have not been targeted and traveling in groups should be safer than traveling alone.

Five groups we are aware of (there may be others) that are still booking tours appear below. If you go on one of these tours, please give us a report about your impression of the number and condition of the monarchs and let us know of your experience in general.

U. S. Department of State Travel Warning
The U. S. Department of State’s Bureau of Consular Affairs (travel.state.gov/) provides a lot of good information for those traveling abroad, including a current “Travel Warnings” page. So what exactly is a travel warning?

“Travel Warnings are issued when long-term, protracted conditions that make a country dangerous or unstable lead the State Department to recommend that Americans avoid or consider the risk of travel to that country. A Travel Warning is also issued when the U.S. Government’s ability to assist American citizens is constrained due to the closure of an embassy or consulate or because of a drawdown of its staff.”

On September 10, 2010 Mexico was added to this list which, as of this writing, includes 30 other countries. Please see the Mexico Travel Warning page for complete information.

Plant Fundraisers

In case you haven’t gone through the text on our Bring Back The Monarchs website, one of the things we are trying to facilitate is helping anyone who holds plant fundraisers (nature centers, zoos, native plant societies, schools, etc.) acquire wholesale plants, particularly milkweeds, that can be sold at these events.

We recently received an email from a teacher who wants our help acquiring plants for a spring plant fundraiser that is going to be held at her school. We are contacting nurseries all over the country who grow milkweeds to see what is available. We are careful to identify to the sources of seeds used for plugs to be sure that plugs used for restoration were grown from seeds from the same ecological region.

We need more letters like the one below. Our mission in this project is to help these types of fundraising projects and to promote the planting of milkweeds in both gardens and in areas that can be restored.

If you know of anyone planning a plant fundraiser in 2011, please let them know of our goals and willingness to help them with these projects. Thank You!

Greetings:

I am a teacher at USD 504 Service Valley Charter Academy in Oswego, Kansas.

I attended the spring open house at KU last year and purchased a lot of plants to put in our school registered Monarch Waystation that we created.

I read on the Monarch Watch facebook page about the Bring Back The Monarchs program and our school is very interested in setting up a plant fund raiser for Southeast Kansas. Our school received charter funds 3 years ago. Our charter is built around the use of agriculture to reach our students and this would fit very well into our program. We have a greenhouse on school grounds and would like information on ordering plants wholesale through Monarch Watch.

We have had community individuals stop by the school asking about purchasing milkweed and I am very excited about the possibility of making plants available to our region of the state.

I share the passion of Monarch Watch and this will give my classroom and school a chance to increase awareness in our corner of Kansas.

Thanks for your assistance.

Theresa

Monarch Population Status

If you have been following the news about monarch populations over the last 8 months, you know that the 2009 overwintering monarch population in Mexico covered a forest area of only 1.92 hectares. This figure represents an all time low for overwintering monarchs and is well below the long-term average of 7.44 hectares (1994-2010). We worried about these low numbers because of the possibility that a devastating storm could drive the population even lower. And then it happened…a storm of the worst possible dimensions hit the overwintering area starting on 2 February. Fifteen inches of rain fell over a four day period. Large hail hit some areas and snow and freezing temperatures were reported subsequently during another period of precipitation. The consequences were devastating for the residents of the monarch overwintering area. Accounts of the flooding and landslides can be found in the Mexico category of the Monarch Watch Blog.

Attempts to find out how the monarchs fared following these winter storms were unsatisfactory. No measurements were made of the numbers of monarchs killed by the storms. Accounts by visitors to the colonies after the storms suggested that substantial numbers of monarchs died during these events. Reports from reliable observers suggested that as much as 80% of the butterflies died at some colonies while others suggested moderate mortality at one large colony of perhaps 20%. Overall we estimated that at least 50% of the monarchs died during the winter months, recognizing that this value could have been low.

Our next concern was the number of butterflies coming north in late February and March. Would the number of surviving butterflies be sufficient to establish a first generation in Texas and the South large enough to lead to a recolonization of the northern breeding areas and a recovery of the population?

Fortunately, the conditions encountered by the monarchs that reached Texas were favorable. Rainfall over the previous 6 months signaled an end to the long drought and produced an abundance of milkweed. The fire ants were down due to the drought and temperatures were lower than normal which seems to favor production of first generation monarchs. The result, in spite of the low number of returning monarchs, was a substantial first generation. These butterflies colonized much of the northern breeding area from late April to mid-June; however, not all areas were well colonized.

The numbers of monarchs reaching the northeastern area (New England and New York) seemed to be well below average, leading to the expectation that the fall migration in this region will be low. Rainfall and temperatures in the central area (Ohio, Indiana, Tennessee, etc.) were not ideal as monarchs arrived from the south and the fall population in this region is likely to be below average except for those areas receiving butterflies from eastern Ontario, which reported many arriving monarchs in May and early June. Based on the numbers of arriving monarchs and the abundance of eggs and larvae found by observers, the fall migration in the east north central region (eastern Dakotas to Michigan) should be above average – assuming that temperatures do not reach the 100s before the end of August.

In summary, it appears that the monarchs are making a modest recovery and I expect the overwintering population will measure close to 3 hectares.