Answers From the Monarch Butterfly Expert
Spring 2002

Courtesy of Dr. Karen Oberhauser
(Back to Monarch Butterfly FAQ)

Special thanks to Dr. Karen Oberhauser for providing her time and expertise in responding to your questions.

  • Visit Karen's "Monarchs in the Classroom" education program Website called "MonarchLab"

From: Michigan
Haviland Elementary

Q: Last summer and fall the 2nd graders at Haviland Elementary in Waterford, MI raised and released several monarchs. We noticed that they all emerged from their chrysallises very close to noon. Is this a coincidence or do the butterflies have internal clocks? All of our chrysallises were indoors when they hatched.
Teri Bickmore

A: This is what we observe in monarchs too, and a common pattern in many butterfly species. It is not coincidence, and could either be the result of an internal clock or an ability to detect daylight from within the pupa. Can you think of a reason that it might be advantageous for the monarchs to emerge at this time of day?

From: Utah
South Cache 8-9 Center

Q: Our students were among the first in America to track the migration routes and winter destinations of Monarchs who breed in the Intermountain Region. What are the specific characteristics that distinguish between Western and Eastern Monarch species? ps. Why doesn't Journey North give attention to the Western species of Monarchs?

A: Western and Eastern monarchs are the same species. They can interbreed, and show very few phenotypic (this word refers to their physical characteristics) differences. I can't speak for Journey North, but I'm sure they'd give attention to Western monarchs if more people in the western part of the US reported monarch observations.

Q: It appears that Eastern Monarchs winter in Mexico. Western and Intermountain Monarchs winter in Southern California. Do the Eastern and Western Monarchs ever enter each other's territories throughout their entire life cycle?

A: Yes, there have been several recent reports that suggest that some monarchs from the west overwinter in Mexico, and there also is some evidence that some of the monarchs from the over wintering sites in Mexico fly northwest to become a part of the western population. There is a great deal that we don't know about the degree to which these two populations mix.

Q: Our class agrees that Monarchs are beautiful, and fill and an important niche in ecosystems through pollination, etc. When a serious decline happens in Monarch populations, due to a natural disaster, what can we do to help protect the survivors once they arrive in our areas and face more dangers like tachinid flies?

A: The most important thing that all of us can do for monarchs is to preserve their habitats: during the breeding, migrating and overwintering parts of their life cycles. We can also make sure that they are not exposed to pesticides, and that their host plant, milkweed, is not eliminated due to herbicide use.

From: Texas

Q: Are the migrating monarchs that winter in Mexico able to catch trade winds either direction to hasten their journey, and at what altitudes do they fly?

A: Monarchs are excellent at finding beneficial winds. They will fly at many different altitudes, finding the one with the most advantageous wind speed and direction, and also utilize thermals (areas where warm air is rising). Scientists think that most of the monarchs' flight is accomplished by soaring, rather than using powered flight.

From: New York
Public School 56 Queens - The Harry Eichler School

Q: We live in Glenview, Illinois. We usually have some milkweed plants growing in our yard, and have successfully raised about 75 butterflies over the last 5 years. Usually if we don't collect eggs that are deposited on these plants, they are eaten by ants-- we sometimes see small holes in the plants but the caterpillars always disappear before getting they are even a centimeter in length. So, we usually check the plants frequently and bring the eggs or tiny caterpillars inside where we raise them in a screened cage. We give them free milkweed every day or two, and keep them inside through the crysalis stage. After a butterfly emerges, we release it the same day or the next day, when it's ready to fly. About 90 percent of the eggs that we harvest from our plants become butterflies. A high percentage of the eggs left outdoors on the milkweed plans do not become butterflies. So, here is my question. Do you think it would be worthwhile to sponsor a campaign in the schools to raise monarchs?

A: You have made excellent observations! Our data suggest a similar result, that most monarch eggs don't live to become adults. This is true of almost all insects, and other organisms that produce large numbers of eggs. If you think of the fact that a female can lay hundreds of eggs, it would really be a problem if all of these survived and produced more hundreds of offspring. The best thing that we can do for monarchs is to make sure that the habitat requirements of the survivors are met.

From: Vermont
Ferrisburgh Central School

Q: How many black dots are on the monarch wings? How many white spots? Are there always the same number of spots? Do they have any special meaning? Daniela and Ashley Grade Three.

A: If you mean the black alar spots that are only found on the males, there are two of them. I don't know how many other black dots are there, nor how many white dots are there. I do know that there is some variation in the patterns of the white dots on the edge of the wings. It would be interesting to study this! Have you tried to count them?

From: Massachusetts
New Ludlow

Q: I am a teacher in Massachusetts that has been involved with Journey North for 3 years. During that time I have read journals from teachers that have gone to the sanctuaries to witness first hand the plight of the Monarchs and visit the groves of trees that the Monarchs use as a winter haven. Is it possible to get some information about traveling to these sanctuaries ? Thank you in advance! Mary Ellen Brosnihan

A: Contact Bill Calvert for more information. He's led most of the teacher trips, and can be reached at

From: Alberta

Q: How can a scientist determine if a migratory monarch is in fact stronger and perhaps genetically programmed to live longer? Have any experiments been done: taking eggs from migratory monarchs, freezing or suspending their life and then re-introducing them into a summer position? (To do this one is already introducing other variables that wouldn't make the results as meaningful--eg: the intolerance to such stress could automatically cut down the life span.

A: Migratory monarchs aren't genetically programmed to live longer, since they have the same genes as the non-migratory monarchs. They are, however, physiologically programmed to live longer. Because they are in a state called reproductive diapause, they are not using energy to produce eggs or sperm, nor are they spending time and energy mating. Diapause is induced by environmental conditions, and not different genes. Also, when they are over wintering they are in a state very similar to hibernation; they are inactive, cool, and their metabolism is slowed way down. This allows them to live longer. It is very hard to keep eggs alive for long periods of time, so the experiment you describe would be difficult.

From: North Carolina
First Grade Class

Q: At our local museum's butterfly house, one of the guides told the children that the butterflies would be attracted to spit on their hands. (don't you know their teacher was grateful for THAT information :) ! ) My first graders want to know why butterflies, including monarchs, would be attracted to someone's saliva on a hand.

A: The image of 30 first graders spitting on their hands is lovely! Butterflies are attracted to moisture, and many are attracted to salt. I imagine that sweaty little palms with some spit on top of them would be great for butterflies!

Q: Do monarchs have the same 5 senses that humans have?

A: I had to run through our five senses to think through this one: touch, vision, hearing, smell and taste. Yes, they have all of these, but they're a little different. For example, they hear by detecting air vibrations in many parts of their body try clapping your hands near feeding caterpillars and watch their reaction to observe this sense. They are limited to hearing through ears like we are. They can taste with many parts of their body, including their toes! For more details on monarch senses, you could check out the section on this in the Monarchs in the Classroom curriculum guide .

Q. How did the monarch get the name "monarch"?

A: Most people think that the name "monarch" was conceived because of the connection between William of Orange, the king of England at the time they were given their name, and the colors of the monarch butterfly.

From: Missouri
LEAP program
Sappington School

Q: How long does it take for a butterfly to fly from Missouri to the Mexican sanctuaries in the winter?

A: We don't know exactly, since no one has ever watched one just as they were leaving Missouri and then seen the same monarch as they arrived in Mexico. Tagging data, and observations on departure and arrival dates of many monarchs suggest that this time is about a month and a half.

Q: How much does a Monarch usually weigh, and how do you weigh one?

A: They weigh about half a gram. To give you some perspective, a dime weighs about 2 grams, so it would take 4 monarchs to equal the weight of a dime. We put them in a special kind of envelope and put the envelope on a very sensitive scale, then subtract the weight of the envelope to give us the weight of the monarch.

From: South Carolina
Rock Hill

Q: Where can I obtain milkweed seeds to plant so I can help provide food for the caterpillars?

A: Lots of native plant nurseries have milkweed seed available. This is a great thing to do!

From: Massachusetts
Joyce Middle School

Q: Our classes raised Monarch caterpillars last fall. One of them turned out to be an albino. We chose not to release her because she was not a "wild" butterfly and we learned that releasing her could effect the gene pool. What is the percentage of albino Monarchs in the wild? We also thought that an albino Monarch might be more likely to be eaten by a predator because it does not have the warning colors. Has there ever been a study on the life span of an albino Monarch? Ms. Cerullo's science classes.

A: There are actually very few albino monarchs in the wild. I've never seen one, and I've seen millions of wild monarchs. They are relatively common, however, in Hawaii. Because they're so rare, they haven't been studied in the mainland. I think it's wise not to release butterflies with obvious physical abnormalities that are probably caused by inbreeding in captive populations. We had some in our lab last summer with very strange traits: red eyes, very light colored larvae, and no scales on the adults (the last ones died as they were emerging from the pupa).

Dr. Karen Oberhauser
University of Minnesota
Department of Ecology
1987 Upper Buford Circle
St. Paul MN 55108
612 624-8706 fax: 612 624-6777