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Hummingbird Migration Update: April 11, 2002
Today's Report Includes:
- Rubythroats Marching Up the Map
- Rufous Hummingbirds Starting to Nest!
- Timing is Everything: Link to Lesson
- The One And Only: Challenge Question #8
- Hightailing It! Challenge Question #9
- A Partnership That Works: Try This!
- Frequent Flyers Can't Beat This! Challenge Question #10
- Try This! A Good Name
- Keep Kitty Indoors
- Announcing Poster Contest for National Keep Your Cat Indoors Day
- Up and In: Discussion of Challenge Question #5
- IQ Test: Discussion of Challenge Question #6
- Head Adaptations: Discussion of Challenge Question #7
Rubythroats Marching Up the Map
Ruby-throated Hummingbirds seem to be marching steadily up the map. A look at the leading edge of the migration this week shows first sightings reaching Missouri, Kentucky, West Virginia, Virginia, Pennsylvania, Maryland and Delaware.
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Ruby-throated Hummingbird Courtesy of Lanny Chambers, Hummingbirds.net |
According to the map, which time period has shown the biggest push in the birds' movement? After you look at the map, check out the numbers from recent weeks:
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Number of Sightings |
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Before March 15 |
68 |
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Mar 15 - Mar 29 |
234 |
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Mar 30-Apr 5 |
138 |
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Apr 6-Apr 12 |
44 |
The rubythroats aren't nearly as far north as they were last year at this time. Take a look and compare the two maps below for yourself. What do you think might account for the difference between this year's and last year's migration progress by this date? Weather maps can help you shed some light on this difference:
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April 12, 2001 |
April 11, 2002 |
Rufous Hummingbirds Starting to Nest!
Mike Patterson has some good news to share! On April 1 he reported: "A female Rufous was seen working on a nest in Corvallis, Oregon." Mike also noted the first reports coming in east of the Cascade Range: "Two were along the Columbia River at White Salmon, Washington, and Bingen, Washington, which are late by about 2 weeks, as was a report from Zigzag, Oregon, in the Cascades below Mt Hood. A heard-only bird at Sisters, Oregon, is about 3 weeks early."
Mike's April 8 report included sightings from Bend, Oregon and Sunshine Coast, BC, representing the farthest rufous sightings east and north so far. Do you see these on the map? There were also many additional reports of nest building. Meanwhile, a check of our records shows that by this time last year, rufous hummingbirds had already arrived as far north as Juneau, Alaska, which Mike Patterson said was "pretty much on time."
Rufous hummingbird migration is tricky to understand, and Mike Patterson's project at the Neawanna Wetland Ecological Observatory is designed to discover whether these tiny but hardy rufous hummers really do migrate in response to the availability of certain flowers, or whether there are other factors involved. In flower news, Mike said, "Reports of Salmonberry and Black Twinberry blooming continue throughout the region. Rufous Hummingbirds were actively feeding on Hooker's Willow catkins at the Neawanna Wetland." Learn more about Mike's study here:
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Rufous Hummingbird Courtesy of Mike Patterson |
Timing is Everything: Link to Lesson
Bob Phillips in Manassas, Virginia, saw his first male ruby-throat the morning of April 4, hovering over shallow pools made for small birds. He said, "This is the earliest sighting in the 13 years I have worked with them. Generally they show from 4/14 to 4/20."
In Granbury, Texas, an observer reported on March 31: "They're back--about a week later than last year."
Why do these hummers--and maybe YOURS--return around the same date each year? When the hummers return later or earlier, what might be the reason? Do ruby-throated hummingbirds migrate northward with a particular temperature? For step-by-step directions on how to research this fascinating question and comparing isotherm maps to the progress of the migration, see:
The One And Only
Identifying a hummingbird in the eastern half of the North America is easy. If you see a hummer, it is a ruby-throat. This is the only species that lives throughout the eastern half of the US and most of southern Canada. This makes us wonder:
Challenge Question #8:
"Why don't any other species of hummingbirds live in the East?"
(To respond to this question, please follow
the instructions below.)
Hummer Adaptations: Hightailing It!
Of all the birds on our planet, hummingbirds have the most control of their flight. They can zip up to a flower at top speed and then stop abruptly to hover while sipping nectar, then back up and zip off to another flower. Their wings and pectoral muscles help them do this, but their aerodynamic feats would be simply impossible except for another unique and special feature, their tail. To learn how a hummer tail is specially adapted for the hummer's life, see:
Then answer this question:
Challenge Question #9:
"Hummer tail muscles allow the tail to move up, down, straight, or to either side. Explain how each maneuver changes a hummer's flight."
(To respond to this question, please follow the instructions below.)
A Partnership That Works
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The tiny holes drilled by this Yellow-bellied Sapsucker are an important source
of sweet fluid for Ruby-throated Hummingbirds in early spring. |
Try This!
Using binoculars, look very carefully at the top branch tips of different kinds of trees. Do you see any with tiny
insects swarming at the newly running sap? Can you find any birds up there?
Frequent Flyers Can't Beat This!
Lizz in Antioch, AR spied her first male Ruby April 2 at 4:18 pm central time. She said, "I think he was very tired when he arrived as he was bobbling his head a lot but has since stopped that and just looks around and perches in my dogwood as hummers normally do."
No wonder Lizz's bird looked tired! The wings of these tiny dynamos beat so fast that they look like a blur. (The humming noise made by such rapidly beating wings earned them their common name.) Hummingbirds burn up a lot of energy migrating, but why take our word for it? To figure out just how much work they must do during migration, try figuring it yourself by answering:
Challenge Question #10:
"A Ruby-throated Hummingbird fattens up in the Mexico's Yucatan Peninsula. Then it lights out over the Gulf of Mexico from Campeche. It flies in a straight line to Galveston, Texas. It can't rest or feed while over the Gulf, and it can't soar or glide, so the hummer must beat its wings the whole distance. How many times must the hummingbird flap its wings while crossing the Gulf of Mexico?"
(To respond to this question, please follow the instructions
below.)
To solve this, you will need the following facts:
- The distance between Campeche, Yucatan, Mexico and Galveston, Texas, USA. (Use a map to figure this out.)
- How many miles per hour the hummingbird flies. (The average speed is 29 mph, but let's make the math easier and assume this one is flying at 30 mph.)
- How many hours the hummingbird is flying. (Use the first two facts to figure this out.)
- How many wingbeats per hour. (A scientist used high-speed motion pictures to measure the speed of a Ruby-throated hummingbird's wings in forward flight at 75 beats per second.)
There! Now calculate and remember to send us your answer!
Try This! A Good Name
If we didn't have hummingbirds, would anyone in their wildest imagination dream one up? There are more than 340 species of hummers in the world, but only about one-fourth are called by that name. Elsewhere in the world, these brilliant little creatures have been given names such as coquette, hermit, mango, wood nymph, sun angel, comet, fairy, mountain gem and woodstar. If you had discovered a hummingbird for the first time ever, what would you call it?
Keep Kitty Indoors
During migration, birds are particularly vulnerable to predators. They are unfamiliar with their surroundings, and tired and hungry after the long journey. This makes them perfect prey for a cunning cat roaming outdoors.
True or False? Worldwide, cats may have been involved in the extinction of more bird species than any other cause, except habitat destruction. To see the answer, and to find out why keeping kitty indoors isn't just for the birds, go to:
Announcing Poster Contest for National Keep Your Cat Indoors Day
It's time for the American Bird Conservancy's third national poster competition, and we hope you'll enter! National Keep Your Cat Indoors Day is May 11, 2002, timed to team with International Migratory Bird Day. The aim is to educate cat owners that both cats and wildlife benefit when cats are kept indoors. Enter the contest by creating a poster that depicts a happy indoor cat. Your entry should be in a campaign poster or advertisement style. That's it! The deadline is May 1, 2002. The contest has winners in three age categories: Ages 6-7, 8-9, and 10-12. Winners will be announced by May 11 on American Bird Conservancy's Web site Find out about prizes, poster sizes, and where to mail your entries here:
Up and In: Discussion of Challenge Question #5
Last time we asked, "Why do you think rufous hummers move far north before they move inland?"
Notice the geography of the Western states. When it's warming up along the coast (which is kept warmer by the
ocean than inland locations) the mountains can still be fiercely cold. So it makes sense that hummers will stay
where it's at least a little milder.
IQ Test: Discussion of Challenge Question #6
Scientists know a lot about bird intelligence, but haven't studied hummingbirds very much in the laboratory. We asked, "Why haven't scientists studied hummingbird intelligence as carefully as they've studied the intelligence of crows or pigeons?"
Andrew, Joseph and Stephen, fifth graders from Ferrisburgh Central School in Vermont, said, "The hummingbirds are too tiny to handle easily, so they are more difficult for the scientists to study than the crows or pigeons. The test that the scientists use is called the Krushinsky problem. In it they have two trays, one with food, one without. Then they put them both behind trap doors. The animal then has to find the correct tray. It would be hard to do this with a hummingbird because they are so tiny and can move fast. This is also because they do not walk at all, which makes it very hard to create a test."
Well done, fifth graders! Indeed, bird IQ tests often involve pressing buttons or other maneuvers that hummingbirds are simply too tiny to do. That is the main reason, but there are actually many other reasons. Another is that hummers are protected by law in the U.S. and Canada, and it's hard for researchers to get permits to study them in a laboratory.
Head Adaptations: Discussion of Challenge Question #7
We asked, "How do each of these features serve a hummingbird's unique lifestyle?" Third graders Daniela, Isabelle, Ashley, Laura, Oakes, Sam, and Lillian at Ferrisburgh Central School went through the parts one by one. See their answers together with ours:
EYES: "We read that a hummingbird's eyes were relatively larger than other animals and they can see more colors than humans. Seeing different colors might help them find their food. As they are flying fast, it is good that they have such good vision so they can spot food." They can also see above and behind a little, so they can watch out for hawks and other predators!
EARS: "Their ears are very sensitive. That will help them be quicker to hear predators coming." Unlike hawks and owls, hummingbirds never have to listen for their food!
TONGUE: "Their tongue is thin and long. That helps them drink the nectar from the flowers." It also has a fringed tip, which helps the liquid to "wick" upward.
BEAK: "Their beak is long and thin. This helps them get the nectar from the flowers. Their beak can fit deep into the flower."
feathers surrounding beak: "The feathers surround the beak and that might help them keep the moisture in the beak as they are drinking." Those feathers also stick to grains of pollen, helping the hummingbird to carry the pollen to other flowers. This won't help the hummer while it's eating, but WILL ensure that there are more nectar-making flowers next year!
FEATHERS COVERING EARS: "The feathers surrounding their ears protects their ears from the cold. The feathers would keep things from getting into the ears." They also protect the hummer from whooshy sounds as it zips through the air.
COLORFUL THROAT PATCH: "The colorful throat patch makes them stand out. It might help them disguise them as flowers." It also makes a vivid head-on display when two male hummers are competing for a territory, or when a male is trying to attract a female.
How to Respond to Today's Challenge Questions:
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 #8 (OR #9 OR #10).
3. In the body of your message, answer the question.
The Next Hummingbird Migration Update Will Be Posted on April 18, 2002 (data only).
Copyright 2002 Journey North. All Rights Reserved.
Please send all questions, comments, and suggestions to our feedback form
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