Hummingbird Migration Update: March 11, 2004

Today's Report Includes:

• First Rufous Reaches British Columbia!
• Ruby-throats Arriving! Challenge Question #4
• Hearty Little Birds
• Vagrants and Outliers: What are They?
• Try This! Verifying Data
• Food for Energy: Discussion of Challenge Question #3
• Natural Sap-Tappers: Help for Hungry Hummers

First Rufous Reaches British Columbia!

Mike Patterson shares this week's news as the Rufous hummingbird migration moves through the coast range: “The first report came in from British Columbia at Galiano Island, along with multiple reports from western Washington. The first reported females come from Eugene and Warrenton in Oregon and Port Orchard in Washington, where one was photographed on March 6.” Mike welcomed his own first Rufous, too: “The first Rufous arrived at my feeder on March 5 and I saw at least two at Warrenton on March 7, working the emerging Salmonberry blossoms.”

If you live in the West and see hummers, make sure you report them to Mike. Let Mike know if any flowers are blooming, too!

• Hummingbirds and Flowers

Look at the map above. In what two ways (directions) are the dots for March arrivals different from those for February arrivals? (What you can’t see from the map is that the Feb. 23 report near Coquille was actually in the Oregon Coast range at about 1100 ft.) When do you think the first Rufous hummingbird will reach Ketchikan, Alaska? (It was March 21 in 2003.) Stay tuned!

Ruby-throats Arriving! Challenge Question #4

After the first report on Feb. 25, last week’s data-only report saw the arrival of more Ruby-throats in more Southern/Gulf states. Here’s what recent observers tell us:

Wesley Chapel, FL, March 6: “We have at least two. A large Male and a smaller female. They both look very healthy. They arrived the same time as they did last year. I have 4 feeders up and am very happy to have them back.”
Cypress, TX, March 3: “It is really neat this year. Our two Rufous hummers are still here, but we have our first ruby-throated hummer at our feeders. They usually don't coincide this way.”

Compare the colored dots clustered on this week’s migration map. State a sentence that describes where the Ruby-throat arrivals are first spotted in the U.S. as they arrive from their tropical wintering grounds. (See the range map showing their wintering grounds.) As you think about where ruby-throats are coming from, here’s our question for you:

Challenge Question #4:
“The speed of a hummingbird in normal flight is about 25 mph. About how long will it take a hummingbird to fly non-stop across the Gulf of Mexico, a distance of 845 km (525 mi)?

(To respond to this question, please follow the instructions below.)

Distribution of Breeding and Wintering Rufous and Ruby-throated Hummingbirds. Notice that this map doesn't show the migration between!

Hearty Little Birds
Ruby-throated hummingbirds may fly up to 1,600 km (1,000 mi) from Central America before crossing the Gulf (although some Ruby-throats fly overland in Mexico), and Ruby-throats that nest in Canada must fly another 1,600 km (1,000 mi) or so. This is quite a feat for ANY bird, let alone one that weighs less than two pennies! Here’s more to think about:

A hummingbird’s heart beats about 1,220 beats per minute while in flight, and about 250 times per minute while at rest. How does this compare with YOUR heartbeat at rest and YOUR heartbeat while exercising?

Vagrants and Outliers: What are They?
You saw from one observer’s comment above that Rufous and Ruby-throats were seen in Texas; yet, a look at the range map probably makes that seem unlikely. BUT range maps usually only show the vast majority of a population, not the handful of individual data points from vagrants (“strays”) that some of you see and report. That complicates things, so it’s best to pay attention to a hummingbird’s field marks to know for sure what species it belongs to.

Now, here’s another observer’s report to test your thinking:

Cincinnati, OH, Feb. 28: “I’m 67 years old and have been an outdoor person since I retired in 1984. A lot of this time has been spent making a hummingbird and monarch butterfly habitat. I have been talking to the hummingbirds for years. The call of the hummingbird is what I noticed first and couldn’t believe it. I looked up just in time to see it heading arrow-straight to the SW or SSW. When I first spotted him/her, the hummingbird was about 15 feet away. I am very practiced spotting them and spot them from a hundred feet or so on a regular basis. Of course from that distance, it’s more like the size and flight habit and not field marks. We have been having unseasonably warm weather here and possibly the hummer portends an early spring.”

These two definitions helped as we prepared this week’s hummingbird migration maps, and they'll help you with the journaling Question that follows:

Vagrant or winter hummingbird: Any hummingbird seen between 15 October and 15 March in the eastern and central U.S. or southern Canada.
Outlier: A data point (or points) that lie far outside most of the rest of the points in the data set; An extreme point that stands out from the rest of the distribution.

Is this "outlier" (red dot) a valid Ruby-throat sighting, or not?

Try This! Verifying Data
Journaling Question:
Is the “outlier” described above the first ruby-throat migrant of the season in Ohio? Look at this map showing the outlier and decide if you think it’s a valid ruby-throat sighting. List in your journal all the evidence you feel supports your conclusion. If not a Ruby-throat, what could it be?

After answering the journaling question, compare your thoughts with what three experts told Journey North.

Teacher Tip:
Inquiry strategies might be helpful here. See two lessons to share with students:

• Questions That Help Students Consider Evidence
• You're the Scientist: Verifying Data Collected by Peers

Food for Energy: Discussion of Challenge Question #3
Last time, temps were chilly where hummingbirds were arriving. You learned that it takes a huge amount of energy for these tiny birds to fuel their flight and keep their bodies warm. We asked: "If you burned energy at the same rate as a hummingbird, how much of your favorite food (by weight) 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?" Kaitlin from Mrs. Erdmann's 5th grade TAG class correctly said that “burning as much energy as a hummingbird would require a lot of energy producing food." Your anwers show that you really had fun with this question! From tic tacs to Bugles, we are delighted to share your creative answers:

Could YOU eat 52 bagels an hour???

Ms. Thurber’s class, Grade Five: Izzy, Iz, Lily, Rebecca and Jenn: “This group of girls is about an average of 70 pounds per girl. So, that would mean an average fifth grade girl would have to eat between 105 pounds to 210 pounds of food per day. You would have to eat 6.5 pounds to 13 pounds of food an hour. So - if we wanted to exclusively eat cupcakes, we would have to eat 78 to 156 cupcakes in ONE hour. And then keep that pace up for another 15 hours. According to one resource, about 8 bagels are in a pound. So we would have to eat 52 bagels to 104 bagels an hour. If we just wanted to have sweet breath and only eat Tic Tacs, we would have 166 to 332 boxes an hour. There are 37 Tic Tacs in each box, so that means 6,142 to 12,284 tic tacs. We would not be worried about bad breath!”

Isabella said: “I weigh 44 pounds. I would have to eat about 147 pounds of (30 calories/ounce) ice cream a day, about 9 pounds an hour for 16 hours.”

Kari and Jessie from Mrs. Erdmann's 5th grade TAG class at South O'Brien Middle School answered: "If we burned energy at the same rate as hummingbirds, we would need 18,720 ounces of our favorite food (Bugles) per day, and we would need 1,170 ounces per hour of our favorite food. In pounds per hour we would need 18,72 pounds of Bugles, and we'd need 299,520 pounds of Bugles per day. We figured the average 11-year old is 90 pounds, which is 1,440 ounces. Then, since a hummingbird needs 10 calories per day, we would need 14,400 calories per day. In Bugles there are 160 calories in 1 1/3 cup, so we would need 117 servings of Bugles. That's 18,720 calories!"

Melissa and Staci wrote: “Since hummmingbirds eat 1 1/2 to 3 times their own weight, we (as humans) would have to eat that much. That means that we would have to eat up to that much, to be able to burn that much as a hummingbird does.”

Iselin Middle School seventh graders Sriram, Ariel, Stephanie, and Chris reasoned: “If a hummingbird consumes 10 calories for its 1/10 of an ounce, then 1 calorie is 0.01 of an ounce. One group member weighs 98 pounds or 1568 ounces (98 X 16 ounces in a pound). If 1 calorie is .01 ounces, then 1568 ounces = 156800 calories/day for this student. His favorite food is chips. They have 160 calories per serving. 156800 divided by 160 = 980 servings of his chips per day. Divide 980 servings by 16 hours and he needs to eat 61.25 servings of chip per hour.”

Natural Sap-Tappers: Help for Hungry Hummers
Did all this talk of food make you hungry? Let’s think more about what hummers eat. Like the rest of us, hummers "get by with a little help from their friends." The first Ruby-throated Hummingbirds to return north in the spring usually arrive when weather is still cool or cold. Until a lot of flowers are blooming, they are often very dependent on sapsucker holes for their food. One migrating sapsucker drilled 286 tiny holes in a pine tree in 9-1/2 hours one April day, providing a bounty of food for itself--and for other birds, including hummingbirds. What food? And what makes the sapsuckers essential helpers for other birds to get the food? Find out about this fascinating parnership:

• A Partnership That Works

IMPORTANT: Answer only ONE question in each e-mail message.

1. Address an e-mail message to: jn-challenge-humm@learner.org
2. In the Subject Line of your message write: Challenge Question #4.
3. In the body of EACH message, give your answer to ONE of the questions above.

The Next Hummingbird Migration Update Will Be Posted on March 18* (*data only).

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