Hummingbird Migration Update: February 25, 2003
Today's Report Includes:
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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:
- "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?
- "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:
(To answer these questions, please follow the instructions
below.)
Rufous Hummingbird Migration
Map and Data
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!
What's Your Question? Ask
the Expert Opens February 28!
Is there something about Rufus or Ruby-throated hummingbirds you'd love
to know? This is your chance to ask a pro. Lanny Chambers is our expert,
and starting February 28, he's ready and willing to answer your questions.
Don't miss your chance to Ask the Expert your toughest questions. Meet Lanny
and see how to prepare your questions here:
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.)
Telling Each Other
Apart: Discussion of Challenge Question #1
Last time we asked, "If different hummingbird species are so difficult
for humans to tell apart, what clues do you suppose hummingbirds use to
recognize one another?" 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.
Seeing More Rufous Hummingbirds?
Discussion of Challenge Question #2
Last time we asked, "Every year
more and more Rufous Hummingbird appear in the eastern United States in
winter. Give at least three reasons why winter reports of Rufous Hummingbirds
might be increasing." 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.
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 #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).
Copyright 2003 Journey
North. All Rights Reserved.
Please send all questions, comments, and suggestions to jn-help@learner.org
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