Butterfly Migration Update: November 4, 2005
primeras mariposas monarcas han llegado!
The official word is in! The first monarchs have arrived! On Saturday, October
29th, an estimated one thousand monarchs were seen by Germán Medina
as they flew over his house in the small town of Angangueo.
his report submitted by Estela Romero:
Angangueo, Michoacan (19.62, -100.30)
"Early Saturday morning Germán went to "El Cerrito",
thinking that some butterflies would be there, but he found no butterflies.
Hours later, at noon time, when he was already at home, he says he saw
some "herds" of monarch butterflies flying up towards El Rosario
(sanctuary). He says there must have been around one thousand butterflies.
Today, (Monday, 12:00 noon), he just came from "El Cerrito"
again, and told me that there are now about 5 trees fairly covered with
monarchs. So I think we can say that they have officially arrived!!!"
See full report in English and Spanish:
Cerrito" means "the little hill." It is a high ridge northwest
of town, and it takes just 10 minutes to get there by truck. German knows
"El Cerrito" as the best place to watch for the monarchs' arrival.
He has been visiting regularly hoping to catch sight of the first monarchs
Medina drives tourists to see the monarchs in this truck. He also
coordinates the Symbolic Migration in Mexico.
Romero has graciously translated and sent news about the monarchs
each week. Thank you, Estela!
Lincoln Brower has been studying monarch butterflies for the past
timing was impeccable! Dr. Lincoln Brower was in Mexico the entire week
before and did not see a single monarch. He was doing research inside
the actual butterfly sanctuaries, from October 23rd to 28th. He finally
saw one monarch while driving back to Mexico City! Here's Dr. Brower:
Villa Victoria, Mexico (19.43, -99.98)
"The only monarch we saw from 23 October - 28 October
was one flying over the road 13 miles north of Villa Victoria, Mexico,
on our way back to Mexico City," said Dr. Brower. "We worked
on our field research on Chincua on Sunday (23 October), Monday, Tuesday,
Thursday and Friday, and Pelon on Wednesday. I suspect that, had the
weather been better, that we would have seen more."
Finding a Finish Line About 60 Miles Wide
Stop and think for a minute. The monarchs that are now arriving
at the sanctuaries in Mexico have come from points across eastern
North America. This map shows the HUGE area in North America across
which the monarchs are traveling. The over-wintering region is a
tiny speck on the planet in comparison.
monarch breeding grounds, shown in red on the
map, measure over 3,000,000 square miles!
monarch over-wintering grounds, shown in yellow,
measure only 4,100 square miles.
crossing half a continent, the monarchs must find a finish line about
60 miles wide!
12 major over-wintering sites are shown as red triangles on this
monarchs fly up to 2,500 miles to spend the winter in these mountains.
This! Make a Local Comparison
Just how small is the over-wintering region? Pull out a map of your
state or province. Compare the sanctuary area in Mexico with an area that
is familiar to you:
Sighted in the Bahamas: Where
Did They Come From?
surprised this week when two separate monarch sightings were reported from
the Bahamas! The monarchs were seen on two different islands, over 100 miles
apart. Both observers said they noticed the monarchs suddenly. Each person
reported the butterflies independently, too. Although not as far an over-water
crossing, a tagged monarch was once recovered in Cuba.
Bahamas do have a population of their own, said Dr. Bill Calvert. "The
yearly cycles have been studied and published."
do YOU think the monarchs came from?
"Where do you think the monarchs that were sighted in the Bahamas
came from? Why? Give evidence to support your interpreation."
Saw the Most Monarchs This Week? Migration-rate Math
Follow the link below to a few of this week's observations:
Monarch Butterfly Migration Update Coming Next Week
We will bid farewell to the fall migration season in next week's
update. Watch for a summary of this fall's "migration rate math,"
Challenge Questions, as well as a preview of things to come when Journey
North begins next February. See you next week!
FINAL Monarch Migration Update Will Be Posted on November 11, 2005.
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