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Hummingbird Migration Update: March 10, 2005

Today's Report Includes:


Migration Maps and Data


Distribution Map

Rufous
Hummingbird

(map) (data)

Most data courtesy of Mike Patterson,
Neawanna Wetland Ecological Observatory

Ruby-throated
Hummingbird

(map) (data)

Most data courtesy of Lanny Chambers,
Hummingbirds.net

Rufous Hummingbirds Push North
Mike Patterson sends us news on the Rufous migration from his study site at Oregon's Neawanna Wetland Ecological Observatory. This week brought lots of action, with a solid push into British Columbia and most sites throughout the Willamette Valley of Oregon. Compare the map’s data points with the range map (see Web report). Where do you predict the Rufous hummers will appear next? If you live on the West Coast, report your hummingbirds (and blooming flowers) to Mike:


Another Early Year for Rufous Migration? Challenge Question #3
“ Many (including me) have remarked on the apparent earliness of the migration this year,” says Mike. An early look at the data shows this year to be like 2003, another early year. “To be fair we'll have to wait until after the 90th day for a full accounting. Why? The main movement west of the Cascade Crest usually takes until day 90. But since the peak in normal years is around day 70, we're really not able to make comparisons that represent the entire picture. We need both sides of the bell curve histogram to be fair.” You can see that bell curve on Mike’s histogram/graph.

Challenge Question #3:
“ If the first *migrant Rufous hummingbird was reported Jan. 2, when is day 70 (the peak in normal years)? When is day 90 (when the main movement west of the Cascade Crest has happened)? Do you predict this year’s Rufous migration will continue as one of the early ones? Think about possible setbacks, and explain your prediction.”


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


* We are looking at Oregon/Washington/BC. Mike explains that “all records outside the west coast are either not migrants or they're statistical outliers.”


Following the Nectar Trail: Link to Lesson
When you leave on a long car trip, you like to be sure there will be food along the way. Will restaurants be open when you're hungry? You might say that migratory species must count on the same thing. The blooming of flowering plants is an important part of Mike Patterson’s migration study. Scientists have long thought that some of the migratory species we study in Journey North (such as monarch butterflies and hummingbirds) time their migration to match the flowering and fruiting of various food plants. They follow "flower highways" that are nectar trails to fuel their flights. In the process of moving from one plant to another, these flying critters are not only feeding; they are also pollinating.


Later in the migration, we’ll compare and contrast flower-powered hummingbirds and monarch butterflies. But for now, answer these two questions:

  1. Why are pollinators important to you?
  2. How can you help? See:

Photo Gates
Ruby-throats Arriving!
“ I just returned from Belize, Mexico, where February 24 I observed a Ruby-throated female actively feeding 20 feet from the shore line in 80-degree heat. She seemed no more eager to return to the north than I did,” reports a traveler who lives in Massachusetts.
That hummer may still be in Belize, but other Ruby-throats are on the way! The first arrivals were reported Feb. 19, 24 and 26. Here’s how some of you are welcoming your Rubythroats:
* Tallahassee, FL (March 3): “First Adult Male Ruby Throated showed up this morning at my feeder at 7:30 a.m. This is 3 days earlier than the last 3 years when a male has shown up on March 6th.”
* Wesley Chapel, FL (March 4): “They're here! I put my feeders out March 1. Last year I saw the first one on March 3, but yesterday was cold and rainy. I saw 2 different ones this morning on the feeder outside my bedroom window.”
Look at data points on the map and give a statement that describes where Rubythroats were first seen. Where do you think they’ll be reported next? Is it time to put out your feeder? Check the map for migration progress, and see our tips for getting ready:

Photo Jackie Allison
Feather Phases: Discussion of Challenge Question #2
Last time we introduced you to a molting Rufous hummingbird who was hanging out at Jackie Allison’s flower-filled yard in California. We asked: “Why do you suppose this male hummingbird is molting during winter? (Try to give two reasons why it would benefit the bird.)”

Attracting females is one benefit of new feathers, answered Jharna, Joe, Jasmit, and Oliver (Iselin Middle School, Grade 7). Ruchika, Shannon, Nikita, Hillary, Devin, Serenity, Nicole, and Megan believe the hummingbird molts because “his feathers are worn out and no longer durable and dull-colored wings are not as appealing to females.” Good thinking, all of you! Here’s more from Journey North’s ornithologist, Laura Erickson:
“ Male hummingbirds benefit from having their most striking plumage when it's most important for claiming and defending a territory and attracting a mate. And molting takes a lot of energy! So if they molt through winter, they're going to be at their most brilliant and strongest in early spring. That’s right when they need their strength and beauty most!”


humm_rufousJAllison_14
Photo Jackie Allison
More About Molting: Field Report and Photo Journal by Jackie Allison
“ I had never seen nor witnessed the behavior of a migrating hummingbird in molt,” says Jackie Allison of Nipoma, California. But that changed on January 24 when a molting male Rufous settled on her property. She worried that he would leave for his breeding grounds in the Pacific Northwest before she could see the unveiling of his new "colors." What signs told Jackie the little Rufous was molting when he arrived? How did he respond to Jackie and her camera? How long did he stay? What was his behavior like? Did Jackie get to see his new colors? See:

Molting takes a lot of energy. Jackie explains why, and how hummer behavior changes during molting. She tells how the hummer “war games” change before and after the Rufous’s new “colors” grew in. See:


Got Questions? “Ask the Expert” Opens Next Friday March 18
Once again this year, hummingbird expert Lanny Chambers has volunteered to respond to students' questions. Are you thinking?


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 #3.

3. In the body of EACH message, give your answer to ONE Challenge Question. Please include your school name and town, too.

The Next Hummingbird Migration Update Will Be Posted on March 17, 2005.

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