Winter Sightings! >>
Today's Report Includes:
- News
from the Monarch's Winter Home in Mexico >>
- Dr. Lincoln Brower Back from Mexico
- The Beauty of Butterflies
- Concerns about size of Sierra Chincua sanctuary
- Why Do Monarchs Form Colonies? >>
- Challenge
Question #2 >>
- How much does a branch full of butterflies weigh?
- Answer to Challenge Question #1
- Links: Monarch Butterfly Resources to Explore >>
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| Why
do Monarchs fly to Mexico from across the continent? |
Dear Journey
North,
I've just returned from a research trip to the monarch sites.
The
Beauty of Butterflies
The monarchs' behavior is so gentle and beautiful at this time of year.
They're just dancing embers in the forest. They're like this when they
arrive in the fall — and even now in February. They're not very
stressed yet and haven't gone into their spring moving phase where you
see big explosions and millions flying through the air. It's just lovely
and gentle, like a very sweet part of a symphony. The boughs and trunks
of the trees are draped with curtains of monarchs resting quietly in the
shade.
Concerns
About Size of Sierra Chincua Colony
The Chincua colony is tiny this year and has been small for several years.
(See
graph.) But this year the colony is so small it really worries me.
I think the progressive degradation of the forest is beginning to show
its effect. The Sierra Chincua was a pristine forest years ago, but now
the forest has been severely damaged by illegal logging. (See satellite
image.)
Dr.Brower
(March 2006 photo by Don Davis)
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| Size
of Sierra Chincua Colony >> 1993/1994 - 2007/2008 |
Topography
of Sierra Chincua Colony >> Marked with colony's location in December, 2004 |
Why do monarch butterflies come together by the millions and form colonies the way they do? They crowd together so closely it's hard to tell where one butterfly ends and the other begins. And why do some monarchs cluster on the trunks of trees instead of in branches? Dr. Brower has a hypothesis.
Let's see how the monarchs' unique clustering behavior might help them survive. >>
There can be 15,000 butterflies clinging to a single branch in a monarch butterfly colony. The butterflies are so heavy they can bend branches!
This Week's Question:
- If the typical monarch weighs 500 mg, how much would a branch loaded with 15,000 butterflies weigh? (Give your answer in kilograms and in pounds.)Also, name another object that weighs the same amount, for comparison.
To Respond: Write in your journal and send us your answer for possible inclusion in next week's update.
Answer to last week's question
- Adaptations: Why don't cold butterflies fall? >>
- Math: How many paper clips can bend a branch? >>
- Predation and Survival: Who's Been Eating the Monarchs? Slideshow and Booklet
- Predation: Who ate these monarchs? Look for clues! >>
- Analogies: The Forest as Blanket, Umbrella & Hot Water Bottle (Analogies) >>
- Journal: Monarch Winter Habitat Journal >>
- Overview: About Journey North's Monarch Butterfly Overwintering Study >>
The Next Monarch Migration Update Will Be Posted on February 21, 2008.
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