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Hummingbird
Migration Update: April 21, 2005
Today's Report Includes:
- Latest Migration Maps and Data
- Slow Inland Progress for Rufous Hummingbirds
- Ladies Second: Challenge Question #8
- Rubythroats Make Big Push North
- Activities: Ready for Raising Hummer Babies?
- Totally Terrific Tongues
- Early Rufous Migration: Discussion of Challenge Question #6
- Digging Into Data: Discussion of Challenge Question #7
- Teacher Tip: Scientists "Sample" Data. You Can Too!
Latest Migration Maps and Data
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 Distribution Map |
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| Rufous
Most
data courtesy of Mike Patterson, |
Ruby-throated
Most
data courtesy of Lanny Chambers, |
Slow Inland Progress for Rufous Hummingbirds
You can see from the map that a few Rufous hummingbirds are still heading
north. But reports from the inland or east side of the Cascade Mountain
Range are still running slow, says Mike Patterson from his study site
at Oregon’s Neawanna
Wetland Ecological Observatory, where he
carries out his "Hummingbirds and Flowers" study. Slow inland
progress is not that surprising, given the cooler-than-average and
very unsettled weather. (See the weather maps, below.)
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Study
and compare temperature patterns for 2004 and 2005
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|
 |
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Week
of April 9, 2005
Average temperatures |
Week
of April 10, 2004
Average temperatures |
Ladies Second: Challenge Question #8
Mike did receive two reports east of 120°--one from Oliver, BC and another report of a female Rufous in Lewiston, ID. Mike said, “Reports of females arriving ahead of males are unusual, but seem to occur more frequently in years when the migration is delayed.” That makes us wonder how you might answer our next challenge question:
Challenge Question #8:
(1) Why does it make sense for females to arrive after males?
(2) Why might females arrive ahead of males in years when the migration is delayed?
(To respond to this question, please follow the instructions below.)
Journal and Predict
Compare this week’s Rufous data with the Rufous range map. How
much farther north will the Rufous hummers migrate? Where do you think
they will they move from today’s data points?
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Photo Gates |
Over 100 new sightings! Last week’s sunny weather and southern winds pushed these tiny migrants farther north, with a first sighting in Ontario, Canada! That April 19 sighting report included some details that will confirm what you learned earlier about hummers finding food before the flowers bloom: “There was one lonely Ruby-throated hummingbird at our dock yesterday. He buzzed my husband. We live on a lake. The weather has been unusually warm and summer like...temp today +28C/78F. It has been like this for 5 days. Usually hummers are not here until first week of May. There are no flowers but I did put up my feeder... The maple sap is still running and the yellow-bellied sapsuckers are very busy...maybe this will give the hummer some source of food.”
The latest sightings also include one we always look for: the first Ruby-throated hummingbird for Lanny Chambers, our hummingbird expert. Each spring Lanny collects reports from all over America, and generously shares his data with us for these maps. Lanny’s first Rubythroat arrived this year on April 17!
Into how many additional states have Rubythroats moved this week? If your hummers aren’t home yet, take a close look at the map and decide if it’s time to put your feeders up! Find feeder food recipes and tips here: Unpave the Way for Wildlife Project
Activities: Ready for Raising Hummer Babies?
Last time you learned about hummer nesting phenology and all the steps involved in getting ready to start another generation of hummingbirds. Who gathers nesting materials? Who chooses the nest site? Who builds or repairs the nest? What five purposes does a hummingbird nest have to be capable of?
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In the activity below, we invite you to take the hummer challenge to find and then use materials to make a nest that can serve all five nest purposes. Find the purposes, materials and steps to test your ability as a hummingbird nest builder with our hands-on instructions, here:
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Photo Dorothy
Edgington. |
Then, think about the duties when it comes to raising the young. How doesthe workload compare for hummer males and females? In this next activity, we give you a list of duties in raising the young, and a chart for you to record duties of the males, the females, and duties shared by both. After doing this activity, decide whether you’d like to be a male or a female hummer!
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Totally Terrific Tongues
“First sighting 8:00 AM. Cherry tree in full bloom plus feeder set out
last night. Many flying around cherry tree and flowering
quince bush.”
Do reports like this (from Richmond, Virginia, April 17) give you
visions of hummers sipping nectar? Well, here’s
a surprise! Hummingbirds do not feed by sucking up
nectar with their
bills; instead, they lap
it up with their tongues.
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Sticking their tongues out all day is a way of life
for hummingbirds. Their bills and tongues have evolved
into
fabulous feeding tools
to help them eat many times their own body weight in
nectar every day.
Hummers
feed by dipping their forked, open-grooved tongues
into nectar at up to 12 times a second. The grooves
create
a capillary action
that draws
the nectar up the tongue and into the mouth with every
lap. To reach the nectar at the base of a long flower
tubes, hummingbirds
extend
their tongues past their bill to a distance about equal
to the length of the
bill!
Bird expert Laura Erickson tells us that hummingbird
tongues look like fine thread, but a microscope shows
how very
complex they
are. The
tip is fringed, perhaps for lapping up nectar or
entangling tiny insects. The length of the tongue
is rolled into
two tubes. Nectar
is either
sucked
through the tongue like a drinking straw or pulled
up by capillary
Try This! To see your visiting hummer’s amazing tongue in action, try using a window feeder or one with a clear plastic base.
Early Rufous Migration: Discussion of Challenge Question #6
In confirming the early migration for Rufous hummingbirds, last time we asked: "What variables on the wintering grounds might influence an early Rufous Hummingbird's departure? List as many as you can think of."
Jeremiah mentioned the weather. “It got warmer early this year for a short span. The hummingbirds might have thought that it was warming up for good.” Seventh graders from Iselin (NJ) Middle School also listed the weather---both good weather that makes flowers bloom, and severe weather on the wintering grounds that sends them north in hopes of better weather. Good job!
You’ll see that your thinking is much like Journey North’s expert Laura Erickson, who lists her guesses about conditions on the wintering grounds that might cause an early migration:
- Winter conditions might be better than usual, allowing the birds to get into prime migrating and breeding condition earlier than normal.
- Winter conditions might be worse than usual, sending the birds away in search of better food earlier than usual.
- A sudden warm spell or south winds might send the birds north earlier than usual.
- Habitat
destruction might send birds north earlier than usual.
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Lanny Chambers |
Last time we asked you to look at the data kept by Lanny Chambers, our Ruby-throated hummingbird expert, to answer: "When do you think Lanny's first hummingbird will arrive in 2005? What is the range and what is the median of Lanny Chambers's first arrival dates for Ruby-throated hummingbirds in St. Louis, Missouri?"
Hot off the press! Lanny Chambers confirmed: “We saw our first one on April 17.”
- With a prediction of April 19, Brielle, Jesica and Kasef, 7th graders from Iselin Middle School, were closest. Way to go!
- The range of first sightings is 7 days. (The earliest date was April 16 and the latest date was April 23, so the range between earliest and latest is 7 days.) Good job calculating this answer Ammie, Maninder and Yasmin and Chris!
- The median
of April 19 was correctly calculated
by Ammie, Maninder,
Yasmin, Brielle, Jesica, Kasef, and
also by Joseph. Congratulations!
Teacher Tip: Scientists "Sample" Data. You Can Too!
As hummingbird data flies in from observers each spring, teachers often feel awash in data. You may want to reduce the number of data points students plot on their migration maps. This activity introduces the mathematical idea of choosing random samples--and simplifies mapping! Use our idea of a candy bar to sweeten interest, and take advantage of lesson adaptations for both older and younger students.
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.
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 28*
(data only).
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