Ruby-throated Hummingbird Migration Update: April 17, 1997

• Link to Today's Migration Data

Try This!
Here are some way you can analyze today's hummingbird migration data:

1. On the chart below, list each new state/province from which hummers were reported for the first time. Record the date of first sighting beside the name of the state/province. (For example, we've completed the "Before 3/15/" time period using data from the March 20th update.)

2. Count the number of "new" states within each time interval. Put this number in the 3rd column.

3. Add the total number of states/provinces in which hummingbirds have arrived. Put this number in the 4th column.

4. Now look at the data and see if you can answer these questions:

• Did sightings increase suddenly over a certain time period? Did they stay the same? If so, when?
• Look back at weather maps collected over the past weeks. How might temperatures, high or low pressure systems, or storm systems have affected the migration?
• Compare the hummingbird migration to that of the monarch butterfly. Since both species are sensitive to cold temperatures and live on nectar, how do you expect their movements across the continent will compare? Use the chart below for the monarch data, and look for similarities and differences between the 2 species. ( Click Here for monarch data as of April 15th.)

Dates	Name of State/Province (Date of First Sighting)	# New States/Prov.	Total #
Before 3/15	LA (3/1/97), TX (2/22/97), FL (3/3/97), MS (3/8/97), AL (2/27/97), GA (3/14/97)	6	6
3/16-3/31
4/1-4/15
4/16-4/30
5/1-5/15
5/15-5/31

Ruby-throated Hungry Birds
Perhaps a more descriptive name! Don't let their small size fool you, because hummingbirds are BIG eaters. In fact, no animal on earth has a faster metabolism-- roughly 100 times that of an elephant. Hummingbirds burn food so fast they often eat 1 1/2 - 3 times their weight in food per day. Maybe this explains why people rarely see hummers when they aren't eating. Read Doug Malone's recent report from Smithfield, TN (littlemalone@blomand.net): "Saw Ruby-throated Hummingbird feeding at columbine and fire pink at noon Saturday, April 12, 1997." In order to gather enough nectar, hummingbirds must visit hundreds of flowers every day. And, just one day of cold temperatures or bad luck finding flowers can mean death. Hummingbirds press the limits, and live their lives only a few hours from starvation.

Thus, hummingbirds have devised a fascinating way to conserve energy. They go into a sleep-like state known as "torpor". During torpor, the tiny bird's body temperature can drop by 50 degrees, the heart rate slow from 500 beats per minute to fewer than 50, and breathing may even stop for a period of time. A hummingbird consumes as much as 50 times more energy when awake than when torpid. If you were to find a hummingbird in torpor, it would appear lifeless. If a predator were to find one, it would be lifeless indeed! While torpor has benefits, there are risks too. It can take as long as an hour for the bird to come back into an active state, so a torpid hummer can't respond to emergencies.

It may be hard to imagine the challenges these birds face every day in order to stay alive. Here's a fun activity that will help:

Challenge Question # 3
"If you burned energy at the same rate as a hummingbird, how much of your favorite food would you need to eat per day? Assuming you are awake 16 hours each day, how much food would you need to eat per hour?"

The following steps will help you with this question:

1. Calculate the number of Calories/ounce a hummingbird needs in a day. (A Ruby-throated Hummingbird needs 10 Calories per day and weighs 1/10 of an ounce)

2. Figure your own weight in ounces.

3. If you burned food at the same rate (Calories/ounce) as a hummingbird does, how many Calories would you need per day?

4. How many Calories are in one serving of your favorite food? How much of this food would you need to eat per day?

5. If you're awake 16 hours in a day, how much of your favorite food would you need to eat per hour?

To respond to this Challenge Question please follow the instructions at the end of this report.

Answer to Previous Challenge Questions

"Besides a ruby-throated hummingbird, what other things weigh 1/10th of an ounce?", asked Challenge Question # 1.

"A normal sized marshmallow, 10 1/2 mini M & M's, or a Bic pen," said Gabi Shoemaker of Lock Haven Jr. High School in Lock Haven, PA (nheilman@oak.kcsd.k12.pa.us)

Check out the other clever answers from students:

• Link to Student Answers To Hummingbird Challenge Question # 1

In response to Challenge Question # 2, A typical trip for a hummingbird across the Gulf of Mexico (if a hummingbird beats its wings 4 million times at a rate of 75 wing-beats per second) is approximately 14 hours, " agreed students from

• Iselin Middle School
• Nauset Middle School
• Lock Haven Jr. High School
• Des Lacs Burlington High School
• Ferrisburgh Central School
• Belle Plaine Elementary
• Kanawha Elementary School and
• Bobcaygeon Public School

If you'd like to see how they got their answers, read on:

• Link to Student Answers To Hummingbird Challenge Question # 2

How to Respond to Journey North Hummingbird Challenge Question # 3

1. Address an e-mail message to: jn-challenge-hummingbird@learner.org
2. In the Subject Line of your message write: Challenge Question # 3
3. In the body of the message, give your answer to this question:

Challenge Question # 3
"If you burned energy at the same rate as a hummingbird, how much of your favorite food would you need to eat per day? Assuming you are awake 16 hours each day, how much food would you need to eat per hour?"

Follow the steps listed in this report to help answer this question!

Don't Forget!
Please include the name of your school and your location so we can credit you properly for your answers.

The Next Hummingbird Migration Update Will be Posted on May 1, 1997.