Monarchs in Space: The Return

As most of you know, we were able to send monarchs into space via the shuttle Atlantis on the 16th of November 2009 to be delivered to the International Space Station (ISS) where they lived out their lives. These monarchs are now back in Kansas and will become part of a permanent display at Monarch Watch. The entire venture was a most curious migration, three monarch larvae were sent from Kansas to Florida, delivered to the shuttle Atlantis as part of the payload for mission STS-129 that took them to the ISS. Aboard the ISS they fed on the artificial diet created by Monarch Watch, molting from 4th into 5th instars and into chrysalises, finally becoming adults.

The shuttle Endeavour returned our monarchs to Earth on the 21st of February and from there the monarch habitat was shipped to BioServe Space Technologies at the University of Colorado in Boulder – the specialists who coordinate biologically based science experiments for NASA and with whom we worked to get our monarchs into space. BioServe sent the monarchs back to us on the 4th of March 2010, thus completing a most amazing journey. The entire venture, including our engagement with numerous schools, teacher evaluations of the project, photos, videos, and a summary of what we have learned from this project can be found on our Monarchs in Space page.

The entire adventure gave rise to some curious questions and answers that have parallels with those asked about monarchs all the time. So, the next time someone asks we can truthfully say:

Q: What is the longest distance monarchs have traveled?
A: 40 million miles*

Q: How far have monarchs traveled in one day?
A: 421,371 miles

Q: How fast have monarchs traveled?
A: More than 17,000 miles per hour

Of course, the questions aren’t framed correctly and this is the case for many questions that come from students and the public.

In the classroom the unexpected answer to a poorly worded question can often be used to get students to ask questions that are more incisive and to spark a discussion. Experts will often reframe poorly-worded questions from the public. For example, “How many miles can monarchs cover in one day?”, might become “Assuming you want to know the maximum distance monarchs have been recorded to move from one day to the next, the answer is more than 150 miles.” Or, to provide an answer that is more revealing to the audience, experts may turn the question back on the questioner and ask, “Do you mean by powered flight or do you want to know how far they can advance on weather fronts in a day or two or do you want to know the average speed of flight or average rate of progression of the migration?” The answers to these questions lead to a better understanding of the dynamics of the migration. If you don’t know the answers to these and related questions, you might refer to the Monarch Watch Press Briefings. These questions often turn up in press interviews and we’ve summarized the answers in this text.

So, will there be another Monarchs in Space project?” We don’t know – but wow, this sure was fun! We do have plans to recreate this project here on Earth and will soon have monarch kits designed to allow students to follow the development of monarch larvae in their classrooms and to compare their results with those established for monarchs aboard the International Space Station. Stay tuned!

* The three monarchs left the Earth on 16 November 2009 at 1:28p EST and returned approximately 2337 hours later, on 21 February 2010 at 10:20p EST. At an average speed of 17,210 mph that would make the Lawrence-to-Lawrence journey approximately 40.2 million miles. The Lawrence to Florida and Florida to Colorado to Lawrence portion of the trip doesn’t add much to the overall total.

Post-Storm Status of the Monarch Colonies in Mexico

In previous blog posts we have described the conditions during the breeding season that resulted in a small migratory population, provided the report from Eduardo Rendón (WWFMexico) indicating that the overwintering population was at an all time low (1.92 hectares), and expressed concern about the impact of January and February storms on the overwintering colonies.

Anticipating that it would be difficult for Eduardo and others to assess the colonies due to the devastation of Angangueo and the surrounding area, I asked those who were visiting the monarch colonies to report what on what they have seen. The reports below are from scientists, tours leaders, and tourists. Collectively, these reports provide a general view of the health of the colonies but it remains difficult to assess the extent of mortality due to the winter conditions and the size of the population that will be returning northward.

These reports deal with the following colonies (number that follows indictes the area, in hectares, in December): Herrada (0.06), Sierra Chincua (0.47), El Rosario (0.50), and Cerro Pelon (0.53). There is no information on the remaining three colonies, all were small with a combined area of 0.36 hectares.

A Brief Summary

The small colony at Herrada appears to have been decimated by the winter storms and it would be surprising if more than 30% of the butterflies survived at this location. Although significant mortality was reported by one observer at Cerro Pelon, this colony seems to have survived the winter quite well and should send a good proportion of the original population northward over the next 2-3 weeks. The status of Chincua and El Rosario relative to their original populations is difficult to assess. Chincua appears to have far fewer butterflies than in mid-January and the area shows a considerable amount of damage. At El Rosario monarchs are clustered near the entrance to the trail and are flying and mating with the gusto monarchs typically display at this time in the season but the population is so spread out that it is difficult to determine if the colony is intact or just a small remnant of the original 0.50 hectare colony. We are anxiously waiting for additional reports.

The following reports have been edited for clarity and brevity.

Received from Donald Planey late on the 26th of February:

We just got back from Chincua today. We were supposed to do it yesterday, but we got lost so we just ended up going to El Rosario via Ocampo yesterday*. Here’s what I saw both days:

As far as I could tell at Ocampo (El Rosario), the butterflies were doing great. Unfortunately, we couldn’t see all of it, because the people who operated the trail closed it off after 150-200 meters (5-10 mins from the ticket booth) due to damage to the trail from the storm. However, what we did see was encouraging. There were so many butterflies that I’m not even sure how to estimate their number. At the very least there were thousands and thousands, if not hundreds of thousands. The air was thick with them, and there was hardly a surface that wasn’t covered in monarchs. Most of the pine trees were completely covered, and were even drooping due to the weight. Now, I’d just like to clarify again that we weren’t able to see the entire trail, but what we did see looked great.**

There weren’t as many butterflies at Chincua, but at the same time there was definitely a lot less damage from the storm, not to mention that none of the trail needed to be blocked off by the people managing the trails. We were able to see a section of the forest (at least several hundred square meters) that was also covered in butterflies, but not as densely as in El Rosario. My dad and I agreed that it looked like there simply aren’t as many butterflies at Chincua storm or no storm.

* In a subsequent communication Don confirmed that this road is now open. He added this note: “Although the Ocampo route to El Rosario was open, we were among the only people we saw there the entire time, besides a couple of a Mexican tourists. It looks like the people who depend on this are probably going to get hit hard economically.”

** It sounds like this is the same area visited by Paul and Phill Justice of Rocamar Tours on the 19th as described in another blog post (“Driving Through Mexico After the Storms“).

Received 26 February from Paul and Phill Justice, Rocamar Tours:

Based on numerous visits each year over the past ten years, our visits to Chincua and Cerro Pelon over the past couple of days have been good at best. The butterflies at Chincua are dispersed over a fairly large area so the area available for viewing by visitors is quite limited resulting in a good showing at best. It continues to be unseasonably cold resulting in not near as many butterflies in flight as we have experienced other years. There is considerable wind damage with trees down throughout area, but no tree damage within the sanctuary itself. There are not many more butterflies dead than we would normally expect to see at this time of year.

We reported on Rosario last week. The condition of the sanctuary was quite dismal with very few butterflies and fewer visitors. It was the worst we had seen it.

We visited Cerro Pelon yesterday. The butterflies were 45 minutes from Macheros on horse-back. There were a fair number of butterflies streaming down the valley and onto the lower trail all the way into the village about mid-morning. The streaming would be about half what we would normally see on the trail. By comparison, last year the last week of February and first week of March, the number of butterflies in the air was spectacular and some of the best showings we have ever seen. In the sanctuary itself there appears to be a good number of butterflies in the trees over an extensive area. The fact that the weather continues to be unseasonably cool results in fewer butterflies in the air, even at the ideal time of day. There may very well be a similar number of butterflies in the sanctuary this year, however most are still on the trees. There are very few dead butterflies on the forest floor and no visible wind or rain damage anywhere in the area. The vigilantes told us that even though there are more open areas with flowers and nectar on the other side of the mountain, it has been far too cold for the butterflies to move over to that area. There are virtually no butterflies on the other side (or the “exit side”) of the mountain.

Received 26 February from Bill Calvert and Bonnie Chase:

We visited two Monarch colonies – Chincua on 23 February and Pelon on 24 February.

Chincua: We arrived late ca. 3:00 PM. We found a small largely inactive group strung out along 100m of drainage leading down from the Mojonera Alta into the Arroyo La Plancha. The clusters were small and high indicating that they had moved there from some other location. These are the type of clusters that appear late in the season. We estimate that at their widest, the area that the butterflies occupied was 50 to 30 meters across. But it was difficult to tell because the ejidotarios did not allow us very close to the colony. Some dead butterflies were scattered about, but not so many where we were. Some of the dead ones were greasy indicating that they had frozen or had been preyed upon; others showed no greasy appearance and had flattened abdomens that felt empty when squeezed. These had likely starved. The low vegetation showed frost damage – curled and browned leaves.

Pelon (or Macheros): At the approach to the community of Macheros we found butterflies streaming down (and up) the mountain. There was considerable flight activity – a behavior that we usually encounter later in the season. After an hour’s horse-back ride up the steep slopes of the Cerro Pelon we arrived (ca. 2:30) at the Pelon colony. Here we found a very densely packed colony also strung out along 80m of canyon leading down from the Gota de Agua. This aggregation was not wide (maybe 30 m), being confined by the steep canyon sides. The forest guards explained that this was the largest of three groups that were spread out along the canyon. The day was considerably warmer than the previous day at Chincua. There was much activity – flying, basking and roosting. Our impression was that there were many more butterflies here than at Chincua. A number of dead were strewn about the forest floor, but nothing like in past seasons after major storms. We detected no frost damage to vegetation at the butterfly colony or its approaches.

25 February Herrada (nr. Valle de Bravo). The following account was created from a phone conversation with Tom Emmel.

This colony measured 0.06 hectares in December – perhaps 20-25 trees. Tom Emmel and Court Whelan visited the site on the afternoon of 24 February.

Hundreds of monarchs were crossing the road leading to Herrada from Valle de Bravo. Police were present and driving speeds were reduced to 15km/hr. The horse ride to the colony took about 50 minutes. The colony was located at the top of a west facing valley. The N slope of valley had three trees whose trunks were covered with monarchs while the S slope contained 4 trees with clusters of monarchs. Lots of monarchs were in the air with many seen streaming down the mountain to the west evidently in search of water. Many were seen taking water at a moist area. There were relatively few dead and only one mating pair was seen. The clusters on the trees were located at heights from 12-15 feet at the bottom to 30-35 feet, with bare trunk and branches above 35 feet. Since a large proportion of the butterflies were in flight, the colony was probably larger than the 7 trees seen – perhaps as many as 10 trees assuming all came back to roost.

The colony was located at N 19 11 15.8; W 99 57 40.4 – at an elevation of 10,452.

24 February. A report by phone from Tom Emmel:

Tom Emmel (Expedition Travel, McGuire Center, U. FL) and his entourage visited Cerro Pelon on Saturday 20 February. Their route to the monarchs took nearly an hour. Tom estimated that the area occupied by monarchs to be roughly 3 hectares (note that a guide told Trecia the area was about 1 hectare). The colony was located at 9,072 feet (N 19.22,46.5, W 100.16,4.2). The colony was nothing short of spectacular and Tom declared it was the best viewing experience he has had in 25 yrs of visiting the monarch colonies. There was little evidence of wind damage at Pelon and in the surrounding area. Tom heard nothing about a second colony. There was no evidence of high mortality at this site.

Tom and his party visited Sierra Chincua on the 21st. The butterflies were located to the east at 10,374 feet (N 19.41,11.6, W 100.17,47.0). The number of occupied trees was only about 10% of the number seen in January. The colony is highly scattered along the east side of Chincua and small clusters and groups of occupied trees were found here and there for over 1.5 km as the group descended the trail. There were no signs of massive mortality but the colony had moved and scattered due to the storms. Wind damage was evident throughout the area. The guides maintained that only 10% of the butterflies had died as a result of the storms. Due to the scattered distribution of the living butterflies, it will be very difficult to accurately assess the mortality at this site.

There is still no clear picture of the condition of the colony at El Rosario.

In case anyone is wondering – it is roughly 22 miles from Chincua to Pelon – about two hours of air-time for a monarch.

23 February. The following is a summary of several reports, including that of Trecia Neal from Monarchs Across Georgia.

Visitors to Chincua are being taken to a colony that is only about 20 mins by horse from the head of the trail. One visitor said she only saw 10 trees with monarch clusters, while a second visitor (last Wednesday) only saw 4-5 trees with monarchs, however, the conditions were cold and rainy so the full extent of the colony may not have been evident. Both were under the impression that the colony they saw was the only one at Chincua.

To give you some perspective there was only one colony at Chincua in December and it measured 0.47 hectares (WWFMX report). The tree density at Chincua is usually given as 350 trees per hectare so the colony would have occupied roughly 160 trees at that time.

The Chincua and Rosario colonies were hit by a severe storm with hail and 40-50 miles/hr winds on 14-15 January that evidently had the effect of spreading out the colonies. (An earlier storm may also have helped to disperse the colonies). On 17 January Tom Emmel (Expedition Travel, McGuire Center, U. FL) estimated that the Chincua colony occupied 1.7 hectares (equivalent to almost 600 trees). So, reports of the relatively small number of trees presently occupied at Chincua is shocking. Lets’ hope there is another colony and that the guides were simply directing visitors to the most accessible site.

Although a long time resident in Zitacuaro, Pablo Span, reported seeing (2 February) more dead monarchs at Cerro Pelon than he had ever seen before, Trecia Neal (Monarchs Across Georgia) reported that as of Friday (19 February) the monarchs at Pelon were doing well.

Quoting Trecia – “The butterflies were about 40 minutes up the trail by horse…back where they usually where down the trail into the trees…not up in the meadow area where they have been for the last two years. They were magnificent! I did notice quite a few dead butterflies here, and noticed that the sex ratio was about 2:1 male to female. There was a lot of flying that day, but it was still cool and the butterflies were still shivering to generate heat. They looked to be in quite good condition. We sat at the end of the trail in a swarm of butterflies for about an hour, and I didn’t notice very many tattered butterflies at all, in fact, many of them seemed to be in pristine condition! The guide that we spoke to said that they estimated the colony to be about 1 hectare in size! He said that there was another large group up a little higher, and that they had been moving down the mountain.”

In December there was a single colony at Pelon that measured 0.53 hectares according to the WWFMexico report prepared by Euardo Rendon and his colleagues. Evidently this colony split, moved and spread out over a larger area. It is not uncommon for colonies to spread out over a broader area as the season progresses.

Weather, Storms, and Monarchs

On 13 February 2010 we downloaded the data from our electronic WeatherHawk weather station located in the Sierra Chincua, in the Monarch Butterfly Biosphere Reserve. This instrument is at nearly the same elevation as the Chincua butterfly colonies, and 2 – 4 km east of where the colonies form each year. We provide here a preliminary summary of the severe storm that caused extensive landslides, destruction of homes and tragic loss of human lives in Rosario, Angangueo, and other parts of eastern Michoacán.

Anecdotal accounts on the internet have suggested variable butterfly mortality, from 0% to 80% in different colonies. We have not made direct measures of butterfly mortality in this storm, but our weather records, combined with empirical data from Anderson and Brower (1996), Brower et al. (2004, 2009) and Fink et al. (in prep.) give insight into the interplay between local microclimate and butterfly survival. It is clear that butterflies suffered less than the local citizens …but only by a hair’s breadth.

As is typical of the region’s dry season weather pattern, from 17 to 30 January 2010 no rain fell in the area. Light rain began at about 11 pm on 31 January and fell steadily from 6 am to 11 pm on 1 February, accumulating 3.9 cm (1.5 inches)*. Rain began again at 7 pm on 2 February and was continuous and heavy until midnight on 4-5 February. The total precipitation on 4-5 February was 32.0 cm (12.6 inches); the entire storm produced 36.0 cm (14.2 inches).

We know that this heavy storm must have soaked the butterflies. We also know that in January 2002, a combination of heavy precipitation followed by an early morning temperature plunge resulted in 80% mortality of monarch butterflies (Brower et al. 2004). Butterfly survival and mortality depend not on low temperature and not on precipitation, but on the interaction of the two, because wet butterflies have significantly less freeze resistance than do dry butterflies.

During the recent storm, from 31 January through midnight on 4-5 February, the hourly temperature at our weather station ranged between 1.9 and 8.4 °C; at these temperatures no butterflies suffer freeze mortality. Because the lowest air temperature occurs close to sunrise, the morning temperatures on 5 February were crucial in determining the butterflies’ fate. On this morning, the minimum temperature at our weather station reached -3.02°C at 7:42 am. This was fortunate for the butterflies for two reasons. First, our experimental data tell us that wet, wintering monarchs have sufficient freeze resistance for few if any to be killed at this temperature. For wet butterflies, the crucial range of temperatures is -4 to -6°C: in mid-winter, the majority of butterflies can survive many hours of exposure to -4°C, but almost all will be killed by just a few minutes of exposure to -6°C (Fink et al. in prep). Second, because the oyamel fir canopy buffers the forest temperature, most butterflies in the colonies would have experienced a minimum temperature that we estimate to have been about 4°C warmer inside the forest (Brower et al., 2009).

During the day on 5 February the skies were clear. From late morning through mid-afternoon the temperature was 9 to 12 °C and the relative humidity was very low, between 9% and 11%. These conditions would give the butterflies the opportunity to dry their bodies and wings. This is fortunate, because the next night — 5-6 February — was clear and the temperature dropped to -5.96°C at the weather station. Depending on their specific locations within the forest, if they had not had the opportunity to dry, some monarchs would likely have frozen.

The weather data, therefore, tell us that this major storm very likely did not cause major butterfly mortality. If the skies had cleared earlier on the night of 4-5 February and a morning temperature plunge had occurred while the butterflies were still wet, the outcome might have been dramatically different.

It is well to remember that any thinning of the oyamel forest results in less temperature buffering, lowering temperatures in the forest and therefore increasing the probability of butterfly mortality during the clearing that follows storms. Vigilance is needed to prevent tree removal because the butterflies are overwintering on a microclimatic knife-edge.

Additional news of concern: the Sierra Chincua was reported to have had 15 cm of snow which was melted by rain on 18 February 2010. If conditions similar to those described above prevail, damage to butterflies will be minimal. However, where colonies have formed in and adjacent to thinned forests, the chances of butterfly mortality are much higher.

As of 20 February we are still receiving contradictory anecdotal statements on the extent of the mortality caused in several colonies by all these storms. We will keep you informed.

References:
Anderson, J.B. & Brower, L.P. (1996) Freeze-protection of overwintering monarch butterflies in Mexico: critical role of the forest as a blanket and an umbrella. Ecological Entomology, 21, 107-116.

Fink, L.S., Brower, L.P., Helton, T., and C. Kisiel. In prep. The ecology of cold-hardiness in overwintering monarch butterflies.

Brower, L.P., Kust, D.R., Rendon-Salinas, E., Serrano, E.G., Kust, K.R., Miller, J., Fernandez del Rey, C., & Pape, K. (2004). Catastrophic winter storm mortality of monarch butterflies in Mexico during January 2002. In The Monarch Butterfly. Biology and Conservation (eds K.S. Oberhauser & M.J. Solensky), pp. 151-166. Cornell University Press, Ithaca.

Brower, L.P., Williams, E.H., Slayback, D.A., Fink, L.S., Ramirez, M.I., Zubieta, R.R., Limon Garcia, M.I., Gier, P., Lear, J.A., & Van Hook, T. (2009) Oyamel fir tree trunks provide thermal advantages for overwintering monarch butterflies in Mexico. Insect Conservation and Diversity, 2, 163-175.

*This account does not mention the hailstorm that occurred from 5AM-8AM in Angangueo on 1 February 2010. Estela Romero, our colleague who lives in Angangueo, reported to us that 4-6 cm of hail accumulated during this period, an event that was also recorded on video by others. During this same time period 12 mm of precipitation was recorded at the Chincua Weather Station. We are not certain at this time whether it also hailed at Chincua, an event that might have knocked many butterflies from the trees. Nor is it clear whether hail would have been effectively recorded by our instrument. What we can say is that Angangueo received more than 12 mm of precipitation from 5-8 AM on 1 February. The amount of water in 4-6 cm of hail is uncertain but could have been as much as 2.8-4.3 cm.

Driving Through Mexico After the Storms

The account below describes a trip taken on 19 February 2010 from Tlalpujahua to Chincua, El Rosario, and Cerro Pelon by Paul and Phill Justice of Rocamar Tours. This is the most comprehensive report we have seen of the conditions in the monarch overwintering area.

Paul and Phill have also posted lots of photos via Flickr.

Tlalpujahua to Chincua: the road is clear, there are some minor mud slides and trees across the road, but they have been cleared and cut.

Sierra Chincua: we arrived around 11:00 and it was 40 degrees. There were snow patches in and around the parking lot. We were told that last night it snowed about 4 inches, but that most of it was washed away with rain that followed. There were a moderate number of national tourists there (one bus, one van and a couple of cars). We did not take the time to go in to the butterflies as we knew we had a lot of ground to cover. The road in to the sanctuary is better than we have ever seen it in nine years. Good reliable contacts there told us that the butterflies about 25 minutes down the trail. They are on the trail across the field and not the one up the mountain behind the washrooms. We are told that the majority of the butterflies are hibernating in the trees and there are very few actually in flight.

Chincua to North end of Angangueo: The first 5 minutes leaving Chincua and exactly as they have always been. Further down the road there are two major wash-outs where the road is reduced to one lane. There are also various fairly major mud slides that have all been cleared to allow at least one lane of traffic to pass.

Angangueo: The North end of Angangueo where all the furniture manufacturing shops and homes along the river were is fairly heavily damaged, but we were still able to drive on the road. A number of homes were washed completely into the river along with cars and personal belongings. The area before you reach the split in the road to downtown is devastated. Some houses have as much as 6 feet of mud and rubble inside. There is no road left in this area because it is covered in anywhere from three and six feet of mud and stones. The vehicles along the roadside look like they have been in horrific accidents as large stones and boulders have smashed into them and in some cases ripped the roofs right off of them. We saw a Jetta hanging from a second storey balcony.

In this area the army has brought in heavy equipment including loaders, shovels, graders and bulldozers. The army in particular seemed to have a really good handle on the task at hand. We saw that many residents had returned to dig out their homes using hand shovels and flimsy wheelbarrows. There were many residents in the entire town and it is by no means a ghost town nor does it look like it will become one. There was a steady stream of people up and down the road. State and federal governments are giving out mattresses, hot food and medical care. We saw municipal police with pickups full of free clothing that they were distributing. We also saw a number of emergency vehicles from other municipalities (Uruapan in particular) helping out. There were officials from SEMARNAP, SECTUR, and just about every state and federal group imaginable milling around the streets. Clearly this is getting a lot of exposure from groups that can contribute. A number of cars had announcements on them written in wax crayon with things like “Angangueo, we will pull through” and “Angangueo will not die”, etc. It would take many paragraphs to describe how bad the devastation is in this particular section of road before the split. In other cases homes only 10 or 15 feet from the river were not affected at all. There is one section in particular where the entire side of the mountain washed out right down to bare rock from the top down, a kilometer or more long.

Angangueo bypass to Ocampo: Although much of the new concrete bypass road has caved in and a number of homes with it, beyond the split the road is very accessible. After the right hand turn to Zitacuaro, the balance of the town has very little damage but there has obviously been a considerable amount of water that came through. The road to Ocampo and Ocampo itself show no real evidence of damage.

El Rosario: The road to El Rosario had a few minor mud slides that are almost finished being cleaned up. There is only one washout just before the parking lot for the sanctuary, but it has been temporarily repaired. Just before the turn off for the parking lot there is massive erosion around what is usually a small creek bed. It would measure about 100 feet across. We saw the remains of one concrete house in the middle of this that was completely demolished, but any timber homes in this path would have been washed away for sure. Our guide at the sanctuary confirmed that everything along this creek was washed away, but could not confirm the number of people killed. Upon arrival to the actual sanctuary we were amazed to find only a handful of tourists – a group of maybe 7 from France and a few federal government workers who had come to take a look. The butterflies were only about 100 meters from the new pavilion. They were all hanging in the trees and only maybe a dozen or so in the air when we arrived. The forest floor had about a 50% ground cover of dead butterflies. The butterflies were only in about 20 trees*. The sun finally came out around 1:30 and the temperature rose to about 70 degrees – a number of monarchs took flight, but there simply weren’t the numbers to really appreciate them. There were virtually no concession stands open and our guide informed us that they have not had much traffic at all.

*(From an additional communication: “A guide and friend of ours tells us that the colonies at Rosario have indeed split into smaller colonies around the mountain”.)

Rosario to Zitacuaro: The same ride as always.

Macheros: The road to the sanctuary has very little damage – a fallen tree or two that have been cleared. It was about 70 degrees at the village and we met our very reliable contact there who said that the butterflies are as spectacular as ever. He told us that over November and December they had almost no tourists, but that they are getting more tourism than they have ever had as a result of the inaccessibility and poor showings at other sanctuaries. Some of the guides that would usually use other sanctuaries have been bringing them to Macheros. The village has a number of new concrete roads and a new community building built in the last year. This town is a great example of what a tremendous impact tourism income from the monarch butterfly phenomenon can have.

Monarch Population Status

The last year has been tough on monarchs. Hotter than normal conditions for returning monarchs in the spring of 2009, followed by the fourth coldest summer since 1928 in the breeding areas and less than optimal conditions during the fall migration, resulted in the smallest overwintering population to date, 1.92 hectares (the longtime mean is 7.44 hectares).

This small population was of some concern at the outset and the development of El Niño conditions in the Pacific late last summer was unsettling. Such conditions have been known to be associated with moisture-laden systems that have lead to catastrophic mortality at the overwintering sites. The freezing weather that followed heavy rains in the winters of 2002 and 2004 killed roughly 80% and 70% of the populations in those years. Were something similar to happen this winter, the returning population might be only the equivalent of 0.6 hectares, or less.

We have no prior experience with such a small returning population and it is uncertain whether monarchs in such numbers could recover in one year. Assuming that 80% of the overwintering monarchs died in 2002, and that there was some additional mortality due to normal causes, the returning population that year was probably equivalent to 1.4-1.6 hectares. So, a surviving population of 0.6 or less would certainly be unprecedented, and seemingly vulnerable unfavorable conditions as they move northward into the breeding areas in March and April.

The priorities in the monarch area involve dealing with refugees, the massive cleanup, and the damage to the infrastructure of the region due to recent disastrous storms. News of the monarchs and how well they have survived the storms of January and February are fragmentary and confusing. One of the smallest colonies, Herrada, initially only 0.06 hectares, was hit hard by high winds, rainfall, and freezing conditions. The number of surviving butterflies is said to be quite low but no precise estimate of mortality or survival is available. Similarly, masses of dead butterflies were reported at Cerro Pelon, yet other post-storm reports indicate strong flights.

The colonies at Sierra Chincua and El Rosario are reportedly intact with good flights reported for Chincua. But these reports mean little, since 80% of the butterflies could have been killed while the surviving 20% put on a show good enough to impress the tourists. Detailed assessments are needed of the living and the dead. I’ve been told that such studies are planned and should be completed by the end of the month. Let’s hope that in spite of the winds, hail, rain, and freezes, the number surviving will be enough to repopulate our fields and gardens this summer!

ADDENDUM – 21 February 2010
Unable to wait for an official report on the numbers of monarchs that have survived the onslaughts of the repeated storms at the overwintering sites, I have been soliciting reports from those that lead tours and tourists that have visited the monarch colonies in recent days. The reports are fragmentary but none have been positive and it is keeping me up nights. It seems certain the returning population will be less than a 1-hectare equivalent – perhaps 0.6 hectares or even much less.

The returning numbers make a difference because, even though monarchs have a relatively high reproductive rate, there is a limit in how much recovery we might expect in one year. Let’s look at what happened again after the 80% loss in the winter of 2002. The returning population the following spring was probably close to 1.4 hectares and the following winter the population was 7.64 hectares, a 5.45-fold increase. This is the highest increase seen from one year to the next in the 16 years we have good data on the sizes of the overwintering colonies.

However, even if we suppose that monarchs are capable of a 10-fold increase in one year, once the returning population drops significantly below 0.6 hectares (ha), the chances of a recovery in one year diminish substantially. A returning population of 0.6 ha, with favorable conditions, might get us back to overwintering numbers of 5-6 hectares but a returning population of 0.3 ha would only get back to 2-3 hectares – again with favorable conditions. In both cases, these numbers would be below the long-time average of 7.44 hectares.

Given that we have yet to see a 10-fold increase in monarch numbers in one year, my thinking now is that it will take monarchs at least two, and perhaps more, years to recover from the effects of the last breeding season and the winter of 2009-2010. All of us interested in monarchs are going to have to work especially hard to keep this migration going.

Angangueo Storm – Putting it into Perspective

It seems to be part of the human condition to assign blame whenever things go horribly wrong. Had this or that not been done, the destruction in Mexico might not have been as bad, but it would have been a disaster just the same.

Human abilities to predict the future are generally based on past experiences. The problem is that we don’t remember the past very well nor do we learn from the experiences of others – traits that certainly contribute to the devastation that results from extreme events. Even if we know how to do the right thing, we are often constrained by economics, so try to convince ourselves that “the worst” will not happen, at least not in our lifetime. This sounds like our collective behavior with respect to climate change doesn’t it? But, even planning ahead doesn’t always work. In the United States, the Corps of Engineers plans projects in anticipation of 100-year floods that subsequently seem to occur at 20-30 year intervals! And let’s not forget Katrina – we were told years in advance that the levies designed to protect New Orleans from surges due to hurricanes were insufficient, but nothing was done.

This said, it is hard to plan for the future and even harder to plan for an event that has never occurred before – like extreme rainfall in the dry season. Angangueo and the surrounding communities were certainly not prepared for the amount of precipitation that occurred from 31 January through 4 February. How much rain was there? We may never know. About 15 inches (381mm)* of rain was recorded in Zitácuaro by Pablo Span at Rancho Cayetano, some 16 miles (26km) to the south of Angangueo, and similar amounts probably occurred in the Angangueo drainage.

The drainage in which Angangueo and the upslope communities of Dolores and Catingon lie is most unusual**. Dwellings and businesses crowd the narrow valley floor for about 3 miles over a fall in elevation of 1000 ft or more. Many houses are backed up to a small stream, Rio Puerco, that drains through the valley, and housing festoons the steep, mostly deforested, slopes on either side of Angangueo. It is a pattern of living that has lasted for a very long time, as the town itself is hundreds of years old. Much of the town is now lost since the culverts designed to handle normal, even heavy, rainfall couldn’t handle the deluge – nor could the rain-soaked slopes withstand the burden of saturated soils, slipping here and there burying residents in their homes.

The devastation to the town’s infrastructure, the loss of homes and businesses, the landslides, and the groaning and rumblings of some hillsides that threatened additional landslides, led to the evacuation of most, if not all, of the inhabitants of this picturesque mining town on 10 February. There have been numerous reports in the Mexican press about relocating all of the residents of Angangueo, but this won’t happen. The town will come back and when it does, let us hope for the sake of the residents and the future of the town that lessons have been learned. Hopefully, the drainage will be reengineered and sensible restrictions applied as to where people live. Reforesting the valley’s slopes should be a priority as well to reduce runoff and the chance of future landslides.

*For Michoacán, the average precipitation for January and February combined was 17.9mm for the period 1941-2005. July received the most precipitation, 185.4mm. So, 15 inches, or 381mm, of precipitation (if that was indeed the amount that fell between 31 January and 4 February) was more than double the average rainfall for the wettest month.

**The rivers of Angangueo. This map shows the rivers or drainages that converge on Angangueo. Rio Puerco drains the valley NE of Angangueo running parallel to the road from Sierra Chincua continuing down slope through the town. This stream is joined by four other rivers coming from the east; Rio El Charco, Rio San Luis, Rio Carrillo, and Rio Santa Barbara.

Weather Maps of Mexico Storms

Satellite imagery of the track of the moisture-laden system that moved through central Mexico 1-5 February:

Precipitation 30 January – 5 February (for reference, 50 millimeters is approximately 2 inches):

Total Precipitation 1-7 February (for reference, 150 millimeters is approximately 6 inches):

Videos of Angangueo Storms and Aftermath

Local residents posted many videos of the storm and the subsequent damage; the destruction of Angangueo was also covered by several news agencies in Mexico. The annotated list that follows contains videos we thought would be most informative. As you look at these videos, note the high watermarks on the buildings. The high water destroyed shops and the first floors of many homes on the main street.

The first part of this 9-minute video shows the hailstorm that occurred on Monday 1 February (video indicates the hail occurred on the 2nd but a visitor to the area and a local resident maintain that the hail occurred on the first). Additional footage, probably from the 3rd, shows a raging Rio Puerco and you can see where the rushing waters take down a foot bridge. Later footage from the 4th shows an even more turbulent river eroding away the foundations of a building. The ending shots show a landslide that destroyed numerous homes and took several lives:

Slideshow of damage in valley north of the central plaza with some shots of a landslide:

Short videos showing water running down the west side of Angangueo at 7:40-7:48 AM on 5 February:

Water rushing into main street from the east near Hotel Juarez and Romero store 8:06AM, 5 February:

A compilation of scenes of the damage to Angangueo accompanied by “Bearing the Cross” created by John Debney for the “The Passion of the Christ” soundtrack:

Interview with Governor of Michoacan, Leonel Godoy, with background shots of destruction, 9 Feb or earlier:

Reporter describing destruction while standing in front of the cultural center. 5 February:

Reporter describing devastation and rescue activities showing the work of the Army, Cruz Roja, and volunteers; finishing with an interview of the parish priest, 6-7 February:

Other videos appear in the “Angangueo Storm” playlist on the Monarch Watch YouTube Channel.

Map of Angangueo and the Surrounding Area

We have created a Google map of the municipality of Angangueo (near the monarch overwintering sites in Mexico) and the surrounding area. Placemarks have been added to identify buildings, locations, and other features that have been discussed in reference to the disastrous storms that have affected this region in recent weeks. You may navigate around the map below, view a larger map, or download the actual map file (angangueo.kmz) for use with Google Earth.

View Angangueo in a larger map

Timeline of the Disaster in Angangueo

The notes that follow are reconstructions of the disastrous events that occurred in the municipality of Angangueo (in the area of the monarch butterfly overwintering sites in Mexico) from 31 January to 10 February 2010. This timeline is based on weather records and fragments of information gleaned from emails and news accounts. If any of you know of items that should be included in this timeline, or of corrections that are needed, please contact us.

31 January – moderate rainfall

1 February – hail storm at end of front number 28

2 February – front number 29 arrives bringing heavy rains

3 February – heavy rains continue, affecting 20 states in Mexico

4 February – continuation of heavy rains over central Mexico, many areas flooded – landslides begin in Angangueo – several dramatic rescues – people begin leaving – central plaza flooded with water coming from both the north and east – high water and destruction of buildings and bridges along the stream (Rio Puerco) that runs through town – torrents rip through town sweeping away cars and trucks in a rush of water filled with logs and boulders – skies clear around midnight with temperature around 50F(10C)

5 February – flooding continues but subsides as day progresses – overnight lows of 36F(2C) – the sun appears for the first time in 5 days – the exodus continues – searching the landslide for victims – damage assessment and clean up begins

6 February – assessment and clean up continues – overnight lows of 27F(-3C) – more people leave for shelter in nearby towns

7-9 February – heavy equipment is used to clear roads

10 February – the army takes control and Angangueo is officially evacuated