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Hummingbird Migration Update: March 29, 2001
Today's Report Includes:
- Ruby-throated Hummingbirds Screech to a Halt!
- Rufous Hummingbirds Heading Uphill: Challenge Question #8
- Egg-to-Fledgling Countdown: Challenge Questions #9 Through #14
- Try This! Ruby-Throat or Rufous?
- Debra's Hummer Howdy Tradition Continues
- Teacher Tip: Timing the Migration
- Rufous Hummer Homework: Challenge Question #15
- Natural Sap-Tappers Help Hungry Hummers
- Teacher Tip: Hummingbird Metabolism
- Keep Kitty Indoors
- Poster Contest: National Keep Your Cat Indoors Day
- Discussion of Challenge Questions #3 Through #7
Ruby-throated Hummingbirds Screech to a Halt!
What an interesting week to look at the migration! As today's migration map shows, the hummingbirds made very little progress during the past week. Notice that there are few sightings farther north of where the "leading edge" of the migration was last week.
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Ruby-throated Hummingbird Courtesy of Lanny Chambers, Hummingbirds.net |
If you live in the eastern U.S., did you notice colder weather last week? These temperature maps show that, where the hummingbirds were, temperatures were well below normal last week. Notice also that the average temperatures were almost identical in that region for the past two weeks. The hummingbirds must have decided to stay put! Let's watch how the migration changes next week, if the temperatures warm up.
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Temperature departure from normal |
Average Temperatures |
Average Temperatures |
Interested students should look at these daily temperature maps, and see how cold it became. On what date did the temperatures drop in Tennessee, for example?
- Link to: Weather Map Archives
Rufous Hummingbirds Heading Uphill
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Rufous Hummingbird Courtesy of Mike Patterson |
Meanwhile, researcher Mike Patterson of Oregon's Neawanna Wetland Ecological Observatory sends this news from the West Coast: "There were more reports of Rufous hummingbirds from British Columbia last week. Birds also continue to move up slope from the Willamette Valley, with more reports from the Coast Range and foothills of the Cascades." This makes us wonder:
Challenge Question #8
"Why do you think Rufous hummingbirds arrive so much later in the Coast Range and foothills of the Cascades than they do in the Willamette Valley?"
(To respond to this question, please follow
the instructions below.)
Egg-to-Fledgling Countdown
Last time we ended our photo safari with Happy Birthday and two brand new hummer hatchlings. This week we'll follow the babies to day five of their lives in Dorothy's maple tree. Continue the adventure, and please REMEMBER to click on each photo for facts and details to help you answer the Countdown Challenge Questions. (NOTE: When you click on each photo, you'll also see some comments and the question.) Here are this week's photos and questions:
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Challenge Question #9
"What are at least two things that baby hummingbirds CAN do as soon as they hatch out?"
Challenge Question #10
"What is a reason why most birds don't grow feathers over their whole bodies but only in tracts?"
Challenge Question #11
"Why do human eyelids show more of the eye than a bird's eyelids show?"
Challenge Question #12
"While still blind, how do baby hummers know when their mother has returned with food?"
Challenge Question #13
"What things can you find in your classroom or home that are about the size of this hummingbird nest?"
Challenge Question #14
"What DO hummer babies have that helps them stay warm when Mom is away?"
(To respond to these questions, please follow the
instructions below.)
Try This! Ruby-Throat or Rufous?
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Debra's Hummer Howdy Tradition Continues
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"Finally!...I was getting worried...my first of the season was a little female drinking her heart out!" On March 15, Debra King of Meridian, MS (32.2636N,-88.4935W) spotted her first hummingbird of 2001. (Last year's date was March 13.) Each year Debra fills more than 8 feeders a day for hungry hummingbirds! Debra welcomes the birds with more than food. Here's a picture of the sign she made for a fine hummer howdy!
Teacher Tip: Timing the Migration
Why do Debra's hummers--and maybe YOURS--return around the same date each year? 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:
Rufous Hummer Homework
"I used to have ruby-throated hummers in southern New Jersey. I have now relocated and am living in northwest Las Vegas. I do believe that we get the rufous hummingbird. Are they here all year long? When do they come? Our temperature is in the 70's now and am looking and looking for hummers." -Denise
Good question, Denise! The Ruby-throated Hummingbird is the only hummer normally found in the eastern US and Canada, but a dozen different hummingbird species are found in various regions west of the Mississippi River. The hot, dry desert location of Las Vegas might seem to be a bad place for birds that require sweet liquid nectar. Still, five hummingbird species spend at least part of the year there, and one species can sometimes be found there year-round. Readers, can you help Denise?
Challenge Question #15
"When do you think Denise should look for Rufous Hummingbirds in Las Vegas? Which other hummingbirds might she find there in spring?"
HINT: Using the range maps in a Field Guide, research which hummingbirds are likely to appear in Las Vegas.
Then use an encyclopedia or other resource to find information about the climate of Nevada. Based on the range
map and the climate, what are your answers to the questions above?
(To respond to this question, please follow the
instructions below.)
Natural Sap-Tappers Help Hungry Hummers
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Many other birds love sap, but without those woodpecker beaks they can't get it themselves. So sapsucker holes are important for many species, including warblers, kinglets, and phoebes. The first Ruby-throated Hummingbirds to return north in the spring often depend on sapsucker holes for their food before many flowers are blooming.
Sapsuckers probably love maple sap as much as we do, but we usually see them on aspen trees rather than maples. Sap runs best in healthy trees with healthy, strong bark and wood. Maple trees are hardwoods, and it's hard work for even a powerful woodpecker to dig through their tough bark and wood. Even very healthy aspens have much softer wood, so sapsuckers have an easier time tapping them.
Teacher Tip: Hummingbird Metabolism
Ruby-throated hummingbirds may be the tiniest birds on the planet, but they are the biggest eaters. No animal has a faster metabolism--roughly 100 times that of an elephant. Perhaps Ruby-throated "hungrybirds" is a more descriptive name!
But what happens to these "hungrybirds" during cold snaps, rainy weather, cold nights, or days of bad luck finding food sources? These tiny birds have devised a fascinating way to conserve energy when they can't be eating. Find out all about it--and why feeders with perches are dangerous for hummers on cold mornings. Then follow our steps to calculate this answer: "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?" It's all here:
Keep Kitty Indoors
"We are excited at waiting and watching for the hummingbirds to appear. One year a cat caught and killed one and so I made sure that the feeders are away from any possible entrapment and that they are safe," wrote Dorothy Eveland from Cross City, Florida. Dorothy's letter reminds us of a message that's important to the well being of our backyard birds.
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. Cats are dangerous predators for birds at other times of the year, too. For example, most young birds leave the nest before they can fly well. Whenever you see newly fledged baby birds on the ground or taking short practice flights, remember that they are easy prey for a cat. There's an easy solution: Keep kitty indoors.
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 why keeping kitty indoors isn't just for the birds, go to:
Poster Contest: National Keep Your Cat Indoors Day
The American Bird Conservancy's first national poster competition was held last year and attracted entries from 28 states. Did you enter? This yearís contest will yield winners in three age categories: Ages 6-7, 8-9, and 10-12. The deadline for competition entries is May 1, 2001, so you have plenty of time to create your entries. Your poster should depict a happy, safe, indoor cat. Winners will be announced by May 12 on American Bird Conservancy's Web site. Find out about prizes, poster sizes, and where to mail your entries at this site:
Discussion of Challenge Questions #3 Through #7
Thanks to all of you who sent great answers: Brady, Myriah, Ben, Evan, Dylan, Bhavin, David, and Adam. Keep sending your answers; we read them all! Because we're asking so many challenge questions in connection with the Countdown photos, we are placing the responses to those questions on their very own Web page. Then you can refer to them whenever you are ready to discuss the answers. Here's where you'll find the discussion of Countdown Challenge Questions #3 through #7 from our March 15 report:
How to Respond to Today's Challenge Questions:
Please 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 or #11 or #12 or #13 or #14, or #15).
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 April 12, 2001.
Copyright 2001 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form
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