U.S. Department of Health and Human Services
National Cancer Institute (NCI) http://www.nci.nih.gov

For Immediate Release

Lung Tumor  – Photograph by Moredun Animal Health Ltd/Science Photo LibraryA scanning electron micrograph provides a color depiction of a small cancerous tumor within a human lung. The tumor is covered in microscopic hairlike structures called microvilli, which enable absorption and secretion. Smoking and other tobacco use are responsible for nearly all cases of lung cancer.

A New NIH study projects survivorship and costs of cancer care based on changes in the US population and cancer trends.

Based on growth and aging of the U.S. population, medical expenditures for cancer in the year 2020 are projected to reach at least $158 billion (in 2010 dollars) – an increase of 27 percent over 2010, according to a National Institutes of Health analysis. If newly developed tools for cancer diagnosis, treatment, and follow-up continue to be more expensive, medical expenditures for cancer could reach as high as $207 billion, said the researchers from the National Cancer Institute (NCI), part of the NIH. The analysis appears online in the Journal of the National Cancer Institute.

The projections were based on the most recent data available on cancer incidence, survival, and costs of care. In 2010, medical costs associated with cancer were projected to reach $127.6 billion, with the highest costs associated with breast cancer ($16.5 billion), followed by colorectal cancer ($14 billion), lymphoma ($12 billion), lung cancer ($12 billion) and prostate cancer ($12 billion).

If cancer incidence and survival rates and costs remain stable and the U.S. population ages at the rate predicted by the U.S. Census Bureau, direct cancer care expenditures would reach $158 billion in 2020, the report said.

However, the researchers also did additional analyses to account for changes in cancer incidence and survival rates and for the likelihood that cancer care costs will increase as new technologies and treatments are developed. Assuming a 2 percent annual increase in medical costs in the initial and final phases of care – which would mirror recent trends – the projected 2020 costs increased to $173 billion. Estimating a 5 percent annual increase in these costs raised the projection to $207 billion. These figures do not include other types of costs, such as lost productivity, which add to the overall financial burden of cancer.

“Rising health care costs pose a challenge for policy makers charged with allocating future resources on cancer research, treatment, and prevention,” said study author Angela Mariotto, Ph.D., from NCI’s Surveillance Research Program. “Because it is difficult to anticipate future developments of cancer control technologies and their impact on the burden of cancer, we evaluated a variety of possible scenarios.”

To project national cancer expenditures, the researchers combined cancer prevalence, which is the current number of people living with cancer, with average annual costs of care by age (less than 65 or 65 and older). According to their prevalence estimates, there were 13.8 million cancer survivors alive in 2010, 58 percent of whom were age 65 or older. If cancer incidence and survival rates remain stable, the number of cancer survivors in 2020 will increase by 31 percent, to about 18.1 million. Because of the aging of the U.S. population, the researchers expect the largest increase in cancer survivors over the next 10 years to be among Americans age 65 and older.

“The rising costs of cancer care illustrate how important it is for us to advance the science of cancer prevention and treatment to ensure that we’re using the most effective approaches,” said Robert Croyle, Ph.D., director, Division of Cancer Control and Population Sciences, NCI. “This is especially important for elderly cancer patients with other complex health problems.”

To develop their cost projections, the authors used average medical costs for the different phases of cancer care: the first year after diagnosis, the last year of life, and the time in between. For all types of cancer, per-person costs of care were highest in the final year of life. Per-person costs associated with the first year after a cancer diagnosis were more varied, with cancers of the brain, pancreas, ovaries, esophagus and stomach having the highest initial costs and melanoma, prostate and breast cancers having the lowest initial-year costs.

These new projections are higher than previously published estimates of direct cancer expenditures, largely because the researchers used the most recent data available – including Medicare claims data through 2006, which include payments for newer, more expensive, targeted therapies which attack specific cancer cells and often have fewer side effects than other types of cancer treatments. In addition, by analyzing costs according to phase of care, which revealed the higher costs of care associated with the first year of treatment and last year of life (for those who die from their disease), the researchers were able to generate more precise estimates of the cost of care.

The researchers used 2005 incidence and mortality data from NCI’s Surveillance, Epidemiology and End Results (SEER) program to estimate cancer prevalence for 2010 and 2020. Population estimates for the United States was obtained from the U.S. Census Bureau’s National Interim Projections for 2006 to 2020. Medical cost estimates were obtained using the SEER-Medicare database which links SEER data to Medicare claims data from the Center for Medicare and Medicaid Services.

More information about these cost projections is available at: <http://costprojections.cancer.gov>

NCI leads the National Cancer Program and the NIH effort to dramatically reduce the burden of cancer and improve the lives of cancer patients and their families, through research into prevention and cancer biology, the development of new interventions, and the training and mentoring of new researchers. For more information about cancer, please visit the NCI Web site at <www.cancer.gov> or call NCI’s Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).

The National Institutes of Health (NIH) — The Nation’s Medical Research Agency — includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit <www.nih.gov>.


REFERENCE: Mariotto AB, Yabroff KR, Shao Y, Feuer EJ, and Brown ML. Projections of the Cost of Cancer Care in the United States: 2010-2020. Jan 19, 2011, JNCI, Vol. 103, No. 2.


International Stroke Conference (ISC) 2011

Medscape.com, February 14, 2011, by Susan Jeffrey, (Los Angeles, California) — A new report from the Rotterdam Study finds a link between advanced age-related macular degeneration (AMD) and an increased risk for intracerebral hemorrhage (ICH).

Researchers found that both the dry and the wet forms of late AMD were strongly and independently associated with ICH but not with cerebral infarction.

“This is a remarkable finding that has not been reported before,” lead author Renske G. Wieberdink, MD, an epidemiologist at Erasmus Medical Center in Rotterdam, the Netherlands, said at a press conference here.

“However, we should be cautious when interpreting the results because although we reported a strong association, it’s important to realize that our results are based on quite small numbers of late AMD and brain hemorrhage.”

Only if replicated in larger cohorts may the findings have clinical implications, she added.

Their report was presented here at the American Stroke Association International Stroke Conference 2011.

Common Mechanisms?

Both AMD and stroke frequently affect elderly populations, and several risk factors for these conditions overlap, including hypertension, smoking, elevated cholesterol levels, and carotid artery disease, the authors point out. “It has been hypothesized that stroke and AMD may have a common underlying pathway,” Dr. Wieberdink said.

In this study, they examined the association between the presence of AMD and stroke risk and stroke subtypes by using the large population-based elderly cohort enrolled in the Rotterdam Study. The cohort includes 6207 participants who were 55 years of age or older and free of stroke at baseline between 1990 and 1993.

Participants were then continuously followed for stroke through linkage of the Rotterdam Study database with general practitioners’ files and nursing home records. If a stroke was reported, hospital records were obtained to classify stroke subtype.

AMD was evaluated by using fundus photographs at baseline and at each follow-up visit. Severity of AMD was categorized into 5 stages ranging from 0, indicating no AMD, to stage 4. Stage 4 was further divided into what is known as atrophic (“dry”) AMD or neovascular (“wet”) AMD.

Follow-up for incident stroke was complete up to January 1, 2007. During that period (a total of 69,152 person-years of follow-up), 726 strokes occurred, including 397 cerebral infarctions and 59 intracerebral hemorrhages; stroke type for 270 was not specified.

After adjustment for potential confounders including systolic blood pressure, current smoking, and diabetes mellitus, the investigators found a “modest” association between stage 4 AMD and an increased risk for any stroke. However, late AMD, both dry and wet, was associated with a more than 6-fold increase in ICH, although not with cerebral infarction.

Risk for Stroke in Late-Stage AMD vs No AMD

Comparison Hazard Ratio (95% CI)
Stage 4 AMD (any stroke) 1.56 (1.08 – 2.26)
Late AMD (ICH) 6.11 (2.34 – 15.98)

CI = confidence interval

There was no association between early (stage 1 to 3) AMD and stroke or any subtype.

Dr. Wieberdink stressed that these results should be considered preliminary because of the relatively small number of events. Further, the mechanism of the relationship is unknown.

“We don’t think there’s a causal relationship between AMD and stroke,” she said. “Instead, we think that AMD and bleeding stroke may result from a common underlying disease process. However, further research is required to further unravel the nature of the relationship between late AMD and stroke.”

The follow-up period in this study predates some of the newer treatments for AMD, such as anti-vascular endothelial growth factor therapy, that may also affect stroke risk, Dr. Wieberdink noted.

Steven Greenberg, MD, professor of neurology at Harvard Medical School and director of hemorrhagic stroke research at Massachusetts General Hospital Stroke Research Center, moderated the press conference here.

He also emphasized the preliminary nature of the findings but pointed out that if the relationship is real, it could affect clinical decision-making in these patients with AMD.

“If it were replicated and it was a clear study, the most straightforward question that patients want to know is whether this should affect your decision to use blood-thinning agents, at the mild end, like aspirin, or at the strong end, like warfarin or some of the other strong anticoagulant agents,” he said.

Commenting on the findings, Philip B. Gorelick, MD, MPH, John S. Garvin Professor, head of the Department of Neurology and Rehabilitation, and director of the Center for Stroke Research at the University of Illinois College of Medicine, Chicago, also agreed that further replication of the results is required.

“Advanced stages of AMD may be associated with brain hemorrhage, but it’s too early to know for sure because if you look at the confidence intervals based on the estimate of risk here, they’re wide, and we’re going to need further validation of this finding in other large datasets.”

Because risk factors for both of these conditions are similar, he noted, “it would pay, currently, to control those risk factors to try to reduce the risk of brain hemorrhage, which is heavily related to blood pressure, so blood pressure should be given special attention to be controlled.”

The researchers have disclosed no relevant financial relationships.

American Stroke Association International Stroke Conference 2011: Abstract #27. Presented February 9, 2011.

Reed Miller

February 9, 2011 (Montreal, Quebec City) — Another registry study confirms that low-dose radiation from cardiac imaging raises a patient’s risk of cancer.

Results from a cohort study of over 82 000 patients in the Quebec Med-Echo registry by Dr Mark Eisenberg (McGill University, Montreal, QC) and colleagues are published online February 7, 2011 in CMAJ.

The cohort included patients from all over Quebec who were admitted to a hospital with acute MI between April 1996 and March 2006 and had no history of cancer. The registry documented all cardiac imaging and therapeutic procedures involving low-dose ionizing radiation and estimated the patients’ exposure based on the average effective radiation dose for that procedure, ranging from 15.6 mSv for myocardial perfusion imaging down to 7 mSv for diagnostic cardiac catheterization.

A statistical analysis to adjust for the patients’ age, gender, and exposure to low-dose ionizing radiation from noncardiac imaging found that for every 10 mSv of low-dose ionizing radiation a patient was exposed to, his or her risk of developing cancer within five years increased 3%. Of the 82 861 patients included in the cohort, 77% underwent at least one cardiac imaging or therapeutic procedure with low-dose ionizing radiation in the first year after an acute MI. The cumulative exposure to radiation from cardiac procedures was 5.3 mSv per patient-year, of which 84% was in the first year. The patients were diagnosed with a total of 12 020 incident cancers during the follow-up period.

As reported by heartwire , cardiologists, radiologists, and patients are increasingly concerned about long-term effects of the low-dose radiation exposure of patients undergoing some kinds of cardiac imaging, especially patients likely to undergo multiple scans, including MI patients. Eisenberg et al’s study appears to support the recent findings by Einstein et al that MI patients undergo a median of 15 procedures that expose them to radiation and about a third of these patients receive a total dose greater than 100 mSv.

“The potential increase in cancer-related death associated with exposure to radiation from cardiac imaging and therapeutic procedures has to be weighed against the potential risk of death from cardiovascular diseases for which these procedures are indicated and the resulting decrease in mortality expected with their use,” Eisenberg et al write. However, this study is not enough to show where the “balance between these competing risks falls” because it is relatively short and could have been influenced by unknown confounding variables.

In an accompanying editorial, Mathew Mercuri (McMaster University, Hamilton, ON) and colleagues suggest that “a strategy to track radiation doses may help physicians and patients stay aware of the cumulative exposure” and that healthcare and nuclear industries have systems for monitoring exposure to employees, but there currently isn’t any national system for tracking exposure in patients.

This study was funded in part by a grant from the Canadian Institutes of Health Research.

Dan Finnigan, 01.20.11, 2:05 PM ET

For the past couple of years, you have been holding down the fort, keeping expenses and hiring down while waiting for a turnaround in the economy. Nice job. Once again, we have near record profits in the U.S. Consumers are now opening their wallets and, with a workforce again near record highs in productivity, you and your business are clearly getting ready to hire now.

But if you think you’re going to be in the driver’s seat because your company has open positions at a time of prolonged, record unemployment–think again. The top-level unemployment numbers are deceptive. Dig deeper and you will see that there’s a long-term battle for the highly skilled people you will most want to go hire.

Why? By 2015, 60% of the new jobs being created will require skills only held by 20% of the population, according to a recent report from the American Society for Training and Development. In 1991 fewer than 50% of U.S. jobs required skilled workers. But by 2015 76% of all U.S. jobs created will require highly skilled workers, for example people with special skills in science, technology, engineering or math. Worse yet, Georgetown’s Center on Education and the Workforce reports that the demand for college educated workers will outpace the supply in the U.S. by more than 300,000 a year. That means the country will produce 3 million fewer college graduates than are needed over the next decade.

So, you will be waging a war for talent whether you like it or not, a war that requires new strategies and tactics to win. And the fact is that most of us are out of practice, and thus, are likely out of touch with how fast-growing companies hire now.

Two major trends have converged to alter the job-seeking mentality among American workers. First, during the recession, the American worker received the loudest, most clear message in our country’s history: No job is permanent, few employees are irreplaceable, and everyone should be prepared to look for a new job at a moment’s notice. Second, at the same time, social media has advanced so far beyond the tipping point that it has become the cultural norm for making connections and sharing information, both professionally and personally. (Time spent on Facebook now exceeds that on Google, and Facebook now sends more people to news and information websites than does Google’s dominant search engine.)

The result is a new landscape for both employers and job seekers to navigate, a landscape you will have to get to know quickly to attract the talent you need for your company to compete and grow.

If you’ve asked your recruiting team to target passive candidates in the past, it’s time you get to know the new proactive candidates, people who cultivate new job opportunities long before they need them. Our company recently commissioned a national survey, Job Seeker Nation 2010, to find out about the job search intentions and practices of the modern, recession-weary American worker. Our research found that 53% of employed Americans–that is, 63.5 million people–are now open to new job prospects, even if they are not actively looking for a new job per se. But a deeper look into their behavior shows they never stop looking for their next opportunity. In fact, 73% of these proactive candidates have engaged in job search activities in the last 12 months, compared with only 28% of those not open to a new job.

So, then how are these proactive job seekers different from the rest of the population? Very, and much more likely to be the people your company needs. They are:

–Highly educated. 52% are college graduates, while 31% of active job seekers and 44% of those not open to a new job are college grads.

More social. 77% use Facebook, 36% use Twitter, and 34% use LinkedIn–higher adoption rates than other groups reported.

Well-connected. This group has significantly more contacts within these social networks. The difference is even more pronounced when the proactive job seeker has a college degree.

Networking for jobs. Given their large social networks, this group finds referrals even more important as a job source than do others, and they are leading the charge toward using social networks to find jobs.

Let me get to the bottom line: These proactive job seekers–many of whom are some of your best employees, as well–are not waiting for their résumés to be plucked out of a stack of hundreds or found among thousands at job boards. They are cultivating networks of opportunity that they can tap into at any time they need to–like at the next hint of reorganization, layoffs or slow growth in their company.

Smart companies are getting ahead of this. Like the proactive job seeker, proactive employers are cultivating networks of prospective employees to generate the right prospects for their open positions. The fastest-growing companies, like Zynga, Twitter and Groupon, and those that compete with them for talent, provide examples of how employers can reorient their recruiting strategies to attract these motivated, connected and career-minded individuals.

–They’ve gone social. Proactive companies promote jobs in social networks, of course, but they also cultivate networks of followers, engage in online conversations and tell their stories about their companies. This investment pays off for both their marketing and recruiting departments, with new customers and new recruits. To get going: If you have a marketing-driven social media plan, that’s a start. (If not, see Time‘s person of the year award for 2010.) Now layer in content that attracts potential candidates–company news, color commentary from employees, video of the work environment and of course job information. Cover all the big social channels, Facebook, LinkedIn, Twitter and YouTube.

–They’re crowdsourcing their recruiting programs. Employers have long encouraged employees to provide referrals for jobs (the highest- quality source of candidates); and now social technologies offer a way to power up this crowd. The most successful companies have hundreds and sometimes thousands of brand ambassadors in social media, employees who love their company, products and work and are willing to talk about it. They bring a unique perspective to everything from the best latte to the best place to work. To get going: Tell your employees you need their help; give them an easy way to deliver their referrals to your recruiting department; and don’t block access to social networks at your workplace. That’s just handing candidates to your competitors.

–They walk the walk. The top executives in market-leading companies demonstrate their commitment to hiring goals by helping out themselves. If you aren’t hearing about changes in your company’s recruiting strategy, ask. If your human resources executives are pushing changes, get on board. To get going: Stand up at the next company meeting and thank specific employees for their referrals; mention your commitment to hiring the best and brightest in your next press interview; tweet some jobs yourself.

–They know their numbers. If the preceding points sounded touchy-feely to you, don’t be fooled. Proactive employers have transformed their talent acquisition with metrics-driven recruiting programs. They are not wasting time or money sorting through mounds of résumés from under-qualified candidates. They are increasing the yield of their recruiting dollars with targeted programs, intelligent analytics and smarter technologies. To get going: Review the pipeline report from your recruiting department and ask about the candidate sources with the highest return on investment.

An evolution in the marketplace of talent has quietly but irrevocably changed how people look for work and how companies find workers. The faster your company adapts to the new ways of acquiring talent, the more competitive your business will be.

Dan Finnigan is the chief executive officer of Jobvite.

International Stroke Conference (ISC) 2011

Allison Gandey

February 14, 2011 (Los Angeles, California) — Sodium has already been linked to vascular disease, but a new study suggests that excessive intake may also heighten ischemic stroke risk.

“People who consumed more than 4000 mg per day of sodium had more than double the risk of stroke compared to those who consumed less than 1500 mg,” lead investigator Hannah Gardener, ScD, an epidemiologist from the University of Miami Miller School of Medicine in Florida, told reporters attending a news conference here at the International Stroke Conference.

Larry B. Goldstein MD

Larry Goldstein, MD, FAAN, FAHA, Professor of Medicine (Neurology), Director of Duke’s Center for Cerebrovascular Disease, Senior Fellow, Center for Clinical Health Policy Research, National spokesperson for the American Stroke Association

“The data behind sodium consumption is pretty strong and persuasive,” said American Stroke Association national spokesperson Larry Goldstein, MD.

The researchers looked at 2657 people from the multiethnic Northern Manhattan Study. Participants completed a food-frequency questionnaire, and investigators calculated total daily sodium intake by using DietSys software (National Cancer Institute).

During a mean follow-up of 9.7 years, 187 ischemic strokes occurred.

Investigators found that stroke risk, independent of hypertension, increased 16% for every 500 mg of sodium consumed a day.

Those numbers included adjustments for age, sex, race and ethnicity, education, alcohol use, exercise, daily caloric intake, smoking, diabetes, cholesterol, blood pressure, and previous heart disease.

Those consuming 4000 mg or more had a hazard ratio of 2.29 (95% confidence interval, 1.07 – 4.92).

The majority of the cohort, 88%, consumed more sodium than the American Heart Association recommendation of less than 1500 mg a day. US Dietary Guidelines allow for more sodium but still recommend that intake fall below 2300 mg, or about a teaspoon of salt per day.

The average intake was more than double that in the current study at 3031 mg, with a median of 2787 mg daily.

Previous work has suggested that salt consumption hasn’t changed much in the United States over the past 50 years and remains too high.

“People need to read the labels of the food they are eating and see what the salt consumption is and at least try to reduce it toward the levels that are currently being recommended,” said Dr. Goldstein, from the Duke Stroke Center, in Durham, North Carolina.

“It’s clear that small changes in diet can make a huge difference in terms of stroke risk,” Steven Greenberg, MD, vice chair of the International Stroke Conference Committee, said at the meeting.

“The evidence from our study may be used in campaigns aimed at reducing cardiovascular risk,” Dr. Gardener said. “The new American Heart Association dietary goals will help promote cardiovascular and brain health.”

This study was funded by the Javits award from the National Institute of Neurological Disorders and Stroke and the Evelyn McKnight Brain Institute. The researchers have disclosed no relevant financial relationships.

American Stroke Association International Stroke Conference. Abstract #25. News conference February 9, 2011.

International Stroke Conference (ISC) 2011

Diet Soda May Heighten Risk for Vascular Events

Allison Gandey

February 9, 2011 (Los Angeles, California) — Diet soda may not be the healthier alternative many had hoped. A new study suggests that the popular drinks may increase the risk for stroke, myocardial infarction, and vascular death.

“People who had diet soda every day experienced a 61% higher risk of vascular events than those who reported drinking no soda,” lead investigator Hannah Gardener, ScD, an epidemiologist from the University of Miami Miller School of Medicine in Florida, told reporters attending a news conference here at the International Stroke Conference.

The risk persisted after controlling for metabolic syndrome, peripheral vascular disease, and cardiac disease history (relative risk, 1.48; 95% confidence interval, 1.03 – 2.12).

“This is the first report of this association,” said American Stroke Association national spokesperson Larry Goldstein, MD. “I think that it’s always good to do things in moderation. People should look at this information and consider it in the context of their other risk factors.”

The researchers looked at more than 2500 people from the multiethnic Northern Manhattan Study. Participants were asked to report how much and what kind of soda they drank.

During an average follow-up of 9.3 years, 559 vascular events occurred, including ischemic and hemorrhagic stroke.

The researchers also observed a marginally significant increased risk for vascular events among those who consumed moderate or daily regular soda (relative risk, 0.93; 95% confidence interval, 0.74 – 1.16).

As reported by Medscape Medical News, previous studies have suggested a link between diet soda consumption and the risk for metabolic syndrome and diabetes. But this is the first time diet drinks have been associated with vascular events.

“This is an observational study and not a prospective randomized trial,” Dr. Goldstein, from the Duke Stroke Center, in Durham, North Carolina, pointed out. “This is an association and not yet a proven causal relationship.”

The investigators acknowledge that additional studies are needed. The potential mechanisms for the association between diet soda and vascular events remain unknown.

What should clinicians advise patients on the basis of the information we have today? Steven Greenberg, MD, from Harvard Medical School in Boston, Massachusetts, suggests that patients start by concentrating on a healthy diet and regular exercise. “Once the metabolic syndrome is under control and any risk of diabetes, then we can consider cutting back on soda consumption.” Dr. Greenberg is the vice chair of the International Stroke Conference Committee, and during an interview he suggested that patients shouldn’t rush to eliminate diet drinks.

“I do think this is a wake-up call, though,” he said, “and we need to start paying closer attention.”

This study was funded by the Javits award from the National Institute of Neurological Disorders and Stroke and the Evelyn McKnight Brain Institute. The researchers have disclosed no relevant financial relationships.

American Stroke Association International Stroke Conference. Abstract # P55. News conference February 9, 2011.

Photo: National Geographic Magazine, November 2010

GoogleNews.com, FORBES.com, February 14, 2011, MEXICO CITY — Experts are reporting a partial recovery in the annual winter migration of Monarch butterflies to Mexico following a devastating 75 percent drop last year.

The conservation group World Wildlife Federation Mexico says the orange-and-black butterflies from the U.S. and Canada are covering an area of forests that is more than double that of last year, when their numbers dropped to historic lows.

But WWF Mexico director Omar Vidal said Monday the numbers are still well below average.

The butterflies have occupied 9.9 acres (4 hectares) of colonies thus far in the 2010-2011 winter season – more than double the 4.7 acres (1.9 hectares) they covered last year.

They covered almost 20 acres (8 hectares) in the 2008-2009 season.

Monarch Butterflies

Massive migrations of monarch butterflies along the California-Mexico coast can take these airborne insects over 3,000 miles (4,828 kilometers).

Photograph by Hope Ryden


Monarch Butterfly Range

Fast Facts





Average life span in the wild:

Up to 6 to 8 months


Wingspan 3.7 to 4.1 in (9.4 to 10.5 cm)


.0095 to .026 oz (.27 to .75 g)

Group name:


Size relative to a tea cup:

Monarch butterflies are known for the incredible mass migration that brings millions of them to California and Mexico each winter. North American monarchs are the only butterflies that make such a massive journey—up to 3,000 miles (4,828 kilometers). The insects must begin this journey each fall ahead of cold weather, which will kill them if they tarry too long.

Monarch butterflies begin life as eggs and hatch as larvae that eat their eggshells and, subsequently, the milkweed plants on which they were placed. (Monarchs are dependent on milkweed plants, which larvae eat nearly exclusively.)

Fattening larvae become juicy, colorful caterpillars, then create a hard protective case around themselves as they enter the pupa stage. They emerge as beautifully colored, black-orange-and-white adults. The colorful pattern makes monarchs easy to identify—and that’s the idea. The distinctive pattern warns predators that the insects are foul tasting and poisonous.

Butterflies that emerge from chrysalides (pupa state) in late summer and early fall are different from those that do so during the longer days and warmer weather of summer. These monarchs are born to fly, and know because of the changing weather that they must prepare for their lengthy journey.

Only monarchs born in late summer or early fall make the migration, and they make only one round trip. By the time next year’s winter migration begins, several summer generations will have lived and died and it will be last year’s migrators’ great grandchildren that make the trip. Yet somehow these new generations know the way, and follow the same routes their ancestors took—sometimes even returning to the same tree.

Many scientists are concerned about the eastern population of monarchs, which summer east of the Rocky Mountains. This group is occurring in ever smaller numbers, and its survival may be threatened by a series of natural disasters in the Mexican wintering grounds, as well as by reduced acreage of milkweed plants in their summer home.

Monarch butterflies are the most beautiful of all butterflies, some say, and are considered the “king” of the butterflies, hence the name “monarch”. There are lots of very cool things to learn about the monarch butterfly and we’ll try to get through most of them here.

Monarch Caterpillar Becoming a Chrysalis

Monarch Emerging from a Chrysalis

Migration of the Monarch Butterfly

Monarch butterflies are not able to survive the cold winters of most of the United States so they migrate south and west each autumn to escape the cold weather. The monarch migration usually starts in about October of each year, but can start earlier if the weather turns cold sooner than that.

The monarch butterflies will spend their winter hibernation in Mexico and some parts of Southern California where it is warm all year long. If the monarch lives in the Eastern states, usually east of the Rocky Mountains, it will migrate to Mexico and hibernate in oyamel fir trees. If the monarch butterfly lives west of the Rocky Mountains, then it will hibernate in and around Pacific Grove, California in eucalyptus trees. Monarch butterflies use the very same trees each and every year when they migrate, which seems odd because they aren’t the same butterflies that were there last year. These are the new fourth generation of monarch butterflies, so how do they know which trees are the right ones to hibernate in? Monarch butterflies are the only insect that migrates to a warmer climate that is 2,500 miles away each year.

The Monarch butterfly migrates for 2 reasons. They can not withstand freezing weather in the northern and central continental climates in the winter. Also, the larval food plants do not grow in their winter overwintering sites, so the spring generation must fly back north to places where the plants are plentiful. Would you like to help track monarch butterfly migrations? Visit Monarchwatch for lots of information on tracking migrations with a color map.

The monarch overwintering sites are under threat because of people cutting down their favorite trees to build roads, houses and farms. What will happen to the monarchs if they do not have their special trees to spend the winter? There are groups that collect money to save the important trees and educate people about monarch conservation. You can learn more about helping monarchs here.

Our articles are free for you to copy and distribute. Make sure to give http://www.Monarch-Butterfly.com credit for the article.

Monarchs like to hibernate
in the same trees every year.

Western North American Population

Monarchs living west of the Rocky Mountain range in North America overwinter in California along the Pacific coast near Santa Cruz and San Diego. Here microclimatic conditions are very similar to that in central Mexico. Monarchs roost in eucalyptus, Monterey pines, and Monterey cypresses in California.


Traveling South

Eastern North American monarchs fly south using several flyways then merge into a single flyway in Central Texas. It is truly amazing that these monarchs know the way to the overwintering sites even though this migrating generation has never before been to Mexico!

Monarch Butterfly Fall Migration Patterns. Base map source: USGS National Atlas.

Congregation Sites

Monarchs only travel during the day and need to find a roost at night. Monarchs gather close together during the cool autumn evenings. Roost sites are important to the monarch migration. Many of these locations are used year after year. Often pine, fir and cedar trees are chosen for roosting. These trees have thick canopies that moderate the temperature and humidity at the roost site. In the mornings, monarchs bask in the sunlight to warm themselves.

In this Feb. 26, 2009 file photo Monarch butterflies gather on a tree branch at the Monarch Butterfly Biosphere Reserve near the town of Chincua, Mexico.