 |
 |
||||
|
Hummingbird Migration Update: February 28, 2002
Today's Report Includes:
- Migration News: A Few Rufous Record Setters On the Move
- Looking for Nectar in All the Wrong Places?
- Needle in a Haystack: Challenge Question #2
- Staying Alive on Cold Nights: Link to Lesson
- Turning to Torpor: Challenge Question #3
- A Couple of Early Birds That Don't Want Worms!
- Discussion of Challenge Question #1
- Get Set! Help Track the Migration
- Ask the Expert Opens March 1
|
|
Migration News: A Few Rufous Record Setters On the Move
Most Ruby-throated Hummingbirds are still on their tropical wintering grounds right this minute, enjoying sunny skies, toasty temps, and plenty of food. But the western Rufous Hummingbirds are setting some records. Mike Patterson, who collects data on western sightings of Rufous Hummingbirds for his Cascadia Hummingbird Study, had some exciting news this time! On February 18, 2002, Mike wrote:
- "Male Rufous Hummingbirds were reported as far north as Lewis & Clark, just west of Astoria, Oregon by February 14. This is the earliest migrant detection ever recorded for Clatsop County (previous earliest record February 21, and the average first date seen is March 2). The week was remarkably warm for February with daytime temperatures in the mid-50's. This almost certainly contributed to the rapid northward progress. Rufous Hummingbird densities are still very low north of Waldport."
Then, on February 25, Mike sent us VERY exciting news!
- "The most amazing news comes from Nanaimo, British Columbia, where 2 male Rufous Hummingbirds appeared on February 20, 2002, two weeks ahead of the previous first detection record. Overall Rufous densities are still very low with no reports yet between Astoria and Nanaimo and no confirmed sightings between Newport and Astoria. The arrival of the first male to the Willamette Valley in South Eugene, OR, was right about on time, but the appearance of a male at Mt. Tabor in Portland (at the north end of the valley) was a bit early with no reports in between."
 |
Rufous Hummingbird Courtesy of Mike Patterson |
|
|
Ruby-throated Hummingbird Courtesy of Lanny Chambers, Hummingbirds.net |
Journey North participants have also reported rufous hummers in Friendswood and Port Lavaca, Texas! Science Writer Laura Erickson once saw a Rufous Hummingbird in Brownsville Texas during a December cold snap when the temperature dipped to 20 degrees--and it was visiting a place with no feeders! Fortunately, even the hard frost hadn't killed many of the flowers in the garden where it was eating. Rufous Hummingbirds are not common in Texas in winter, but a few of them turn up every year.
Looking for Nectar in All the Wrong Places?
|
|
- December 23, 2001 Adult female in Irmo, SC
- December 24, 2001 Adult female in Rock Hill, SC
- December 31, 2001 Adult female in Gastonia, NC
- January 5, 2002 Adult female in Rock Hill, SC
- January 9, 2002 Adult female in Pinnacle Mountain, SC
- January 12, 2002, Adult female in Pomaria, SC
Since all these birds were adult females, how did Bill know they were different individuals? Because he put a tiny band from the US Fish and Wildlife Service on each one when he caught it. To learn how Bill bands hummingbirds and what he learns from his research at Hilton Pond Center, check out our lesson:
Needle in a Haystack: Challenge Question #2
Bill Hilton Jr. has banded over 2500 Ruby-throated Hummingbirds. Other banders have banded thousands more; yet, not one of these banded ruby-throats has ever been found on its wintering grounds, even though we know where they winter. After seeing what Bill shares in the lesson above, you'll be ready to answer this:
Challenge Question #2:
"Why do hummingbird banders who band thousands of birds re-find so very few?"
(To respond to this question, please follow the instructions below.)
|
|
Look at the Rufous Hummingbird data map and think about how cold it sometimes gets in Oregon and British Columbia. How can those early hummers -- the tiniest of all warm blooded animals -- possibly survive when they go to sleep at night?
Fortunately, they have a special adaptation that allows them to survive cold nights: they turn down their body temperatures in a process called torpor. Imagine yourself trying to keep warm on a cold night when your entire body weighs less than two dimes. (Even some insects and worms would even weigh more than you!) Find out all about the terrific adaptation of torpor here, and do a neat experiment with modeling clay, a balance, a thermometer, and a refrigerator:
Turning to Torpor: Challenge Question #3
Hummingbirds are some of the strongest flyers in the world, and both Rufous and Ruby-throated Hummingbirds are good at migrating. But both species go into torpor at night, even in the middle of summer! Even hummingbirds living in the Central and South American tropics go into torpor. Think about this and what you learned in the Torpor Lesson as you answer:
Challenge Question #3:
"List as many advantages and disadvantages to torpor as you can think of. What are some reasons why hummingbirds would go into torpor rather than just flying where it's warmer at night?"
(To respond to this question, please follow the instructions below.)
A Couple of Early Birds That Don't Want Worms!
Two Journey North participants have already reported Ruby-throated Hummingbirds in 2002! One was Van Howard, who saw a ruby-throat in Vancleave, MS, on January 30. For some reason, a few straggler hummingbirds remain in the extreme south during winter. Some are ruby-throats, but oddly, just as likely are some tropical or western species that are called vagrants because individuals appear regularly out of their normal range. Van's bird may well have been a late ruby-throat; he said the bird hasn't been seen since January 30, and since then there have been a few serious cold snaps.Here's another observer who had a good question:
- "I have been feeding and watching hummingbirds for 25 years. This was the first time I have ever seen a hummingbird in Gainesville in December, January and now February. However, prior to my Feb 20 sighting I had been away from home for about a month, and of course was not here to observe the hummingbirds that I saw in December and January. So how do you tell the migrants from the hummingbirds that have wintered in Florida? It was easy for me last year to report my first hummingbird migrant as I hadn't seen any hummingbirds during the winter months." Hilda Bellot, Gainesville, FL
That's tricky! But only a handful of hummers winter in Florida, and when they visit a feeder regularly, their behavior becomes rather predictable. When ruby-throats start migrating to your area from the tropics, you should notice more activity and even chases between birds.
Discussion of Challenge Question #1: Timing is Everything
|
|
Students from Ms. Thurber's fifth grade class at Ferrisburgh (Vermont) Central
School did some good reasoning. They said: "The climate is warmer and more mild
on the Western coast of the United States. This means that if the Rufous hummingbirds
arrive in their territory, they would have insects that are around and the plants
are in bloom. This means that Rufous hummingbirds would have good food and shelter.
They use spider webs to build their nests. In the east, we do not have flowers or
insects yet. If the Ruby-throated hummingbird came to their breeding territory, they
would not have nest building materials or food! So they are waiting for spring to
come."
Look at the range map and you'll see why Journey North's bird expert Laura Erickson
added these other important facts: "The Rufous Hummingbird is a western species,
and starts its migration from Mexico up the west coast. Because it doesn't have to
cross a large body of water, a rufous can fly small distances at a time. This allows
it to leave as early as weather conditions permit, unlike Ruby-throated Hummingbirds,
many of which cross the Gulf of Mexico to get to the eastern states. Also, because
early rufous migration follows the Pacific coast, where the ocean keeps temperatures
more moderate than they'd be in inland areas, early rufous hummers aren't as likely
to face dangerous low temperatures as Ruby-throated Hummingbirds would in the east."
Get Set! Help Track the Migration
 Report your Hummingbird sightings
to Journey North. |
1. Report when your Hummingbird feeder is up. As soon as you place your hummingbird feeder outside, report to Journey North. Now you're ready to watch for your first hummers!
2. Report the FIRST Hummingbird you see this spring. Let us know when your Hummingbird safely arrives after its long migration.
If you have any questions, contact us: our feedback form
Ask the Expert Opens March 1
Got a Question for the Expert? Your questions are now being accepted for Hummingbird Expert Lanny Chambers. Send them any time in the next 2 weeks BEFORE the deadline of March 15, 2002 at 5 p.m. (Eastern Time).
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
#2 (OR #3)
3. In the body of your message, answer the question.
The Next Hummingbird Migration Update Will Be Posted on March 7, 2002 (migration data only).
Copyright 2002 Journey North. All Rights Reserved.
Please send all questions, comments, and suggestions to our feedback form
|
|
|
|
|
|
|
|
