Migration North

[Jubal]

I have been wondering whether the same Monarch's that have migrated and wintered over in the south, actually migrate up to Northern Indiana as the returning birds do. I have been told that the Monarchs that do arrive in Northern Indiana are the result of several generations gradually arriving in late July and early August. I have been able to find literature to confirm either concept of migration. Information would be appreciated.
Thanks, Jubal

[Jim]

Monarchs that spend the winter in Mexico will only make it back into the Southern part of the U.S. before they die. It is their offspring that will, as adults, continue moving north to repopulate the rest of the continent.

Also see: http://www.monarchwatch.org/tagmig/spring.htm

Hope this helps!

[Jubal]

Jim thanks for the information. The idea that Monarchs repopulate as they travel north thru sucessive generations is amazing. This progression is just so different from the concept of migration that we normally accept. This knowledge certainly reinforces the importance of waystations. I am looking forward to this summer and the appearance of Monarchs in the 10 acres of CRP that we planted last May. The summer was hot and dry but the swamp milkweed germinated well. We observed dozens of Monarch caterpillars on plants that were just 14" tall. Certainly appreciate this web site and have sent links to all parties that would be interested including several prairie nurseries.
Jubal, Waystation 331

[Teresa]

That is awesome Jubal! The more habitats the better! I going to create a 2nd waystation this year for our township. They are very important.

[Paul Cherubini]

I have been wondering whether the same Monarch's that have migrated and wintered over in the south, actually migrate up to Northern Indiana as the returning birds do.
Thanks, Jubal

They do in some years like the spring of 1997. Look at the light green dots on this Journey North map: http://www.learner.org/jnorth/images/gr ... 070897.jpg

[Paul Cherubini]

I have been wondering whether the same Monarch's that have migrated and wintered over in the south, actually migrate up to Northern Indiana as the returning birds do.Thanks, Jubal

The most recent Journey North update shows the overwintered monarchs from Mexico have already reached northern Ohio this year. So they might be in northern Indiana right now as well.
http://www.learner.org/jnorth/images/gr ... 42106.html

[Paul Cherubini]

Now some of the overwintered monarchs from Mexico have even reached Michigan:

http://www.learner.org/jnorth/images/gr ... 42806.html

SIGHTING DATA FROM JOURNEY NORTH WEBSITE:

04/24/06 Greenfield, Indiana
04/24/06 Westmont, Illinois
04/24/06 Newburgh, Indiana
04/23/06 Sandusky, Ohio
04/22/06 Rosalie, Nebraska
04/22/06 Troy, Ohio
04/22/06 Petersburg, MIchigan
04/21/06 Ellettsville, Indiana
04/21/06 Oxford, Ohio
04/21/06 Manchester, Michigan
04/20/06 Wellsville, Ohio
04/20/06 Colchester, Illinois
04/17/06 Montrose, Illinois
04/17/06 Champaign, Illinois

[Mona Miller]

The problem with the data on Journey North is that there are butterfly farmers all over the US distributing butterflies for numerous events.

Dots can be put on maps, but we can't verify that those dots are anything but butterfly sightings. One must assume that they are remigrants from Mexico if they are out early in April, but they also could be butterfly releases.

Butterfly releases are done in Canada, too.

Journey North also does not confirm that the person posting the sighting actually saw a Monarch. I have personally known people who thought Swallowtails and Painted Ladies were Monarchs.

[Paul Cherubini]

The problem with the data on Journey North is that there are butterfly farmers all over the US distributing butterflies for numerous events. Dots can be put on maps, but we can't verify that those dots are anything but butterfly sightings. One must assume that they are remigrants from Mexico if they are out early in April, but they also could be butterfly releases. Butterfly releases are done in Canada, too.

I agree there is some bogus sighting data on Journey North, but nearly all of it is due to butterfly misidentifications, not due to butterfly releases. Example: In warm springs like 1997 there were lots of monarch sightings in the northern States in April and early May on Journey North, but in 1997 the butterfly release industry wasn't well established yet.

Likewise from 1964-1994 - before there was a butterfly release industry - Dr. Urquhart published an annual newsletter that listed reports of spring adult sightings, first spring eggs, first spring caterpillars and so forth and there were lots of sightings in the northern States in April and early May during years with warm Spring weather. Thus there can be no reasonable doubt that in warm years, considerable numbers of spring re-migrants from Mexico make it all the way to North Dakota, Minnesota, Michigan, Ontario and New York.

Further evidence comes from Dr. Urquhart recaptures in the northern States of butterflies that were tagged in Mexico and from Dr. Brower's cardenolide fingerprinting studies where some wild and faded spring migrants caught in the northern States had the cardenolide fingerprint of Asclepias syriaca.

[Mona Miller]

http://plants.usda.gov/java/profile?symbol=ASSY
Scroll down and look at the map for Asclepias syriaca. It even grows in Oregon, which is a western state. I think you may mean isotope study. An isotope study which shows a difference between west and east.
http://monarchwatch.org/read/articles/hiso.htm
Tracking Monarch Migration with Hydrogen Isotopes

Butterfly farming dates back to 1914 and even earlier:
http://query.nytimes.com/gst/abstract.h ... 946596D6CF

When tags are involved, that is a whole different story. Then the data is more real.

When you have observers that may not know a Monarch from a Swallowtail that can be a problem.

[Paul Cherubini]

I think you may mean isotope study. An isotope study which shows a difference between west and east.
http://monarchwatch.org/read/articles/hiso.htm
Tracking Monarch Migration with Hydrogen Isotopes

No I did not mean isotope study. I said cardenolide fingerprinting indicated some re-migrants from Mexico make it all the way to the northern States. Example:
http://www.learner.org/jnorth/spring199 ... Study.html
Dr. Lincoln Brower wrote: "I began collecting adults in this area of Virginia on May 5th, and by 9 May Linda and I were finding many eggs on the freshly sprouting Asclepias syriaca plants. I used our cardenolide fingerprinting technique which indicated that 28 out of 29 butterflies captured between 5 - 18 May had the A. syriaca fingerprint. This is very strong evidence they were spring remigrants that had remigrated from Mexico."

[Mona Miller]

Isotopes is how they fingerprint the milkweed.

http://whyfiles.org/083isotope/2.html

http://www.monarchlab.org/research/Mig/migback4.html

http://www.springerlink.com/content/ffmwneydcf24ja1c/

http://query.nytimes.com/gst/fullpage.h ... wanted=all
On the Trail of the Monarch, With the Aid of Chemistry

http://www.pubmedcentral.nih.gov/articl ... rtid=28060
Natal origins of migratory monarch butterflies at wintering colonies in Mexico: New isotopic evidence