Signs of Spring Update: April 18, 2003
Happy Earth Day, Happy Birthday! It's BIRTHDAY TIME across the Northern Hemisphere. As spring unfolds, Nature welcomes billions of babies--some of them in your own backyard.
It's no coincidence that so many baby animals are born in the spring. Reproductive cycles are timed to maximize the chance of survival.
Natural Laws:
Populations and Ecosystems
Why isn't the world overrun with hummingbirds, monarchs, manatees or caribou--or any other wild creature? Given adequate resources, and no disease or predators, all populations increase exponentially. But throughout the natural world, the growth of all populations are limited in specific niches in the ecosystem by lack of resources and factors such as predation, disease, climate fluctuations, etc. Try This! Seasonal
Births?
Are humans born in specific seasons? Collect a data sample to help you find out. Ask everyone in the room what month they were born. Interview as many people as you can. Record all answers and graph the data by months. Look at the graph to see whether humans are born in specific seasons. Discuss whether the birth season is as important in the life cycle of humans as it is in the life cycle of animals. Explain your thinking. What's Most Important
This Earth Day?
Gaylord Nelson, founder of Earth Day, was asked his vision of the environmental challenges facing the nation and the world. Without pause, he replied:
Among all species, humans have the greatest capacity to shape and adapt to our physical environment, but ALL species have one thing in common: we all depend on the Earth for survival. So on Earth Day 2002, consider what human resource use and population growth mean to all living things. How fast are humans being added to the planet? Listen carefully: Every time you hear a beat, it means there's another person
on the planet. (This is not the birth rate, but the "net gain,"
which means births minus deaths.)
(To respond to this question, please follow the instructions below.) Humankind:
The World's Most Successful Species
For hundreds of thousands of years, the human population was almost stable. Birth and death rates were nearly even, but as this timeline shows, as human inventions improved and extended life, birth rates increased, death rates dropped, and the human population began to grow exponentially.
Can you find these historic events on the timeline? Inequities:
Four Billion Have, Two Billion Have Not
The world is becoming an ever smaller place. Global communications juxtapose the rich and poor, making all aware of our difficult ethical dilemma:
Consider how an ever-growing human population makes environmental, social and political problems fundamentally harder to solve. These are complex issues with no clear answers, yet they are the most important for children to learn about the world they will inherit. Tip to Teachers: Recommended Reading by Dr. Lincoln Brower "I think this is the most important environmental book I've read," says Monarch biologist Dr. Lincoln Brower about The Future Life, written by Edward O. Wilson. Wilson is a Harvard biologist and two-time Pulitzer Prize winner. "It's beautifully written-- a most compelling picture of the impact of overconsumption and overpopulation on our Earth. Basically, we have about 30 years to get our act together. The solution requires a major ethical change in our attitude toward other forms of life."
Spring is an "in between" season as winter turns to summer. And this week summery weather and wintry weather were both happening in many places. Duluth, Minnesota, had 80+ degrees Fahrenheit two days before an icestorm hit. One hungry, fluffed up Yellow-rumped Warbler flitted about Journey North science writer Laura Erickson's yard looking confused. In Eagle River, Wisconsin, Gail Gilson-Pierce heard her first phoebes of the year doing their territorial call at Trees for Tomorrow. Do you know how to recognize the call of a phoebe? Listen to Lang Elliott's recording here: Some people confuse the phoebe's song with the song of the Black-capped Chickadee, probably because the chickadee's "Hey, sweetie!" song is sometimes called the chickadee's "phoebe" song. Listen to the chickadee here: What signs of spring have been popping up in your area? Make sure you tell us about them! Just click on the owl button.
Flowery Math: Discussion of Challenge Question #17 "How many saguaro flowers does a bat have to visit to sustain it for one day? Ginny Dalton, Bat Biologist, tells us, "According to my calculations, 21 flowers. This is because a bat needs 20,200 calories per day and there are 960 calories in each flower. (20,200 calories/day divided by 960 calories per flower = 21 flowers) How to Respond to Today's Challenge Questions:
1. Address an e-mail message to: jn-challenge-spring@learner.org Copyright 2003 Journey North. All Rights Reserved.
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