Hummingbird Migration Update: February 25, 2003


Today's Report Includes:

• Rufous Hummingbirds Ahead of Schedule: Challenge Question #3
• Rufous Hummingbird Migration Map and Data
• What's Your Question? Ask the Expert Opens February 28!
• More of the Rufie Chronicles! Challenge Question #4 and #5
• Telling Each Other Apart: Discussion of Challenge Question #1
• Seeing More Rufous Hummingbirds? Discussion of Challenge Question #2

Adult Male Rufous Hummingbird

Rufous Hummingbirds Ahead of Schedule!
While Ruby-throated Hummingbirds are still hunkering on their wintering grounds, Rufous hummers continue their spring migration. Mike Patterson sends us news on the Rufous migration from his study site at Oregon's Neawanna Wetland Ecological Observatory. Last week, multiple Rufous Hummingbird reports from the Columbia River Estuary suggested that the migration front had reached the 46th parallel as the birds moved north. Mike expected inland reports from the Willamette Valley and Puget Sound to be picking up soon too. (Rufous hummers move not only northward, but inland during their migration.) Sure enough, this week Mike writes: "Over the week, several reports came in from the Puget Sound in Washington and coastal British Columbia. Inland valley reports are also picking up with first detections from Merlin, Salem, Portland and Vancouver, WA. Many observers have noted that these are earlier detections than previous years by 5-10 days." A couple of weeks ago, Mike noted that several flowers are blooming unusually early this year, allowing the hummingbirds to move with their food supplies.

As a result of his ongoing research, Mike points out two other interesting things for you to ponder:

1. "A comparison of migration patterns for the past 3 seasons and the known breeding ranges based on Breeding Bird Surveys shows an intriguingly close correspondence to the major watersheds of the Cascadia Region. Rufous Hummingbirds appear along major river arteries before smaller ones and the "boundary" for breeding is pretty close to the extreme reaches of the Columbia and Fraser River watersheds. Coincidence? I don't think so." Pull out a map of the region and see what Mike means. What questions does this raise for you?
2. "I went through my data on quantifying the amount of green on the backs of Rufous Hummingbirds and found that very red-backed individuals appear to arrive earlier than very green-backed birds. It is generally believed that green-backed individuals are second-year birds (hatched last summer)." Mike thinks it's a good idea to do further study on back color and arrival timing. (This is a great example of how more study leads to more questions!) Using clues in Mike's quotation, what might be some possible explanations for green-backed birds arriving later?

Mike's research project, "Hummingbirds and Flowers," tracks the movement of hummingbirds and the availability of flowers that provide nectar. Nectar from flowers provides essential food for hummingbirds. And hummingbirds are just as important for flowers. Think about how this can be, and then answer this question:

• Challenge Question #3:
  "How do hummingbirds help flowers?"

(To answer these questions, please follow the instructions below.)

Rufous Hummingbird Migration Data Migration Map Courtesy of Mike Patterson Neawanna Wetland Ecological Observatory

If YOU see a Rufous Hummingbird in the West, make sure you report it to Mike Patterson. And if you see hummers, make sure you let him know if any flowers are blooming, too!

• About Ask the Expert:

Photo of immature male Rufous Hummingbird by Bill Hilton, Jr.	How would you like a hummingbird to sit on your shoulder? Read about Patricia's experience!

More of the Rufie Chronicles!
When a rare Rufous Hummingbird turned up in Gerry Stewart's yard, she kept a daily diary from November 17, 2002, through January 4, 2003, keeping track of Rufie's activities. She also heard from friends, like Patricia, who once had a hummingbird sit on her shoulder! See all Gerry's diary entries while you think about today's Challenge Questions.

• The Rufie Chronicles

  Challenge Question #4:
  "Where do you think Rufie slept at night? List at least three special things about Gerry Stewart's yard that helped Rufie choose to spend the winter there."

  Challenge Question #5:
  "Why do you think Rufie stopped coming on January 4? Do you think Gerry will ever see Rufie again? If a Rufous Hummingbird shows up at her feeder, can she ever be sure it's Rufie?"

(To answer these questions, please follow the instructions below.)

Hummingbirds probably notice subtle things about one another that we can't even see, including shape, color, and size, which help them recognize other species and recognize individuals of their own species. Their vision is both keener than ours and allows them to see some ultraviolet colors that we can't detect. They may also recognize one another by wingbeat sound and vocalizations.

Some possibilities:

• Deforestation or other conditions in Mexico are causing the loss of hummingbird habitat down there
• A few Rufous Hummingbirds had a genetic mutation that caused them to migrate a different way, and they survived the winter in the eastern United States. These hummingbirds reproduced the following spring, and their babies inherited the gene to winter in the east. Now after many generations, a population has developed.
• There have always been a fair number of hummingbirds that winter in the east. Now that more people are aware of it, more people are keeping feeders available. The same number is wintering, but thanks to feeders, more of these hummingbirds are being noticed.
• Now that more people are keeping feeders available, more hummingbirds are surviving.

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 #3 OR #4 OR #5.
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 4, 2003 (Data Only).

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Please send all questions, comments, and suggestions to jn-help@learner.org