Butterfly Migration Update: February 6, 2004
We begin each year while the monarchs are still at the over-wintering sites, deep in central Mexico. Their spring migration will begin in March, just a few short weeks away. We hope you're ready to help track their journey north! (See how to prepare below.)
Hello from Sunny Mexico: How's the Weather?
Last fall, the monarchs flew a long distance to a very special place on the planet. The monarchs over-winter on just 10-12 mountain tops, in high elevation fir forests. Everybody knows that monarchs go to Mexico to escape the long, cold northern winters. What do you suppose the weather is like at the monarch sanctuaries, near the town of Angangueo, Mexico?
But wait! Before you look, think about this: How do you imagine the monarchs' winter weather in Mexico? How warm do you think it gets in the daytime? How cold do you think it gets at night? Record your predicted temperatures. Then check the weather report and answer this season’s first Challenge Question:
This winter, we'll explore the key climatic factors that can mean life or death for monarchs in Mexico. Temperatures, frost, dew, sunlight, shade, moisture, elevation and exposure are key variables in the monarch’s unique winter habitat. Record the daily weather data from Mexico on the chart below. Over the weeks, we'll see how each of the variables affects the monarchs:
Monarchs in the News: Matan heladas a monarcas
On Tuesday this week, February 3, Mexican newspaper headlines reported that very low temperatures and a snowstorm killed up to 10 percent of the over-wintering monarch population, some 11 million monarchs. In contrast, the devastating storm back in January of 2002 killed 80% of the population at that time. Those interested and able can read the full story in Spanish in the Mexican Newspaper "Reforma." Search for the headlines, "Matan heladas a monarcas."
All the Eggs in One Basket and Other Analogies
Cold temperatures and snow are among the many threats monarchs face while attempting to survive the winter in Mexico. Just imagine: 10% of the entire overwintering population died last week in a single storm!
It's often said that "all eggs are in one basket" while the monarchs are in Mexico. The over-wintering habitat is considered the "Achilles heel" of monarch survival. In the monarch's annual cycle, this habitat is considered the "weakest link in the chain." Draw images to illustrate these analogies, and explain why good winter habitat is critical for monarchs. When you read, watch how writers use analogies to help readers understand a new concept.
Monarch Population Dynamics: Let Me Count the Ways
Scientists who study population sizes and the many variables that affect them are concerned with "population dynamics." You'll appreciate how challenging the scientists' work is by thinking through this problem yourself! On the chart below, list all the factors you discover that can cause high or low numbers at each stage of the monarch's annual cycle. Keep and maintain this chart during your monarch study. How many variables can you add over time?
Please Report Over-wintering Monarchs Now
How to Respond to Today's Challenge Questions:
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