Hummingbird Migration Update: April 12, 2001
Ruby-Throated Hummingbirds Surge Northward!
But the REAL difference is where the hummers ARE. See it on the map!
Rufous Hummers Reach Alaska!
When will the first Rufous Hummingbirds arrive in Alaska? They already have! The first date a Rufous Hummingbird was reported in Ketchikan, Alaska, was April 1, 2001. And Mike Patterson told Journey North on April 12 that he had just received word that Rufous Hummingbirds were seen in Juneau as of April 8, 2001, commenting that this is pretty much on time.
Rufous Hummingbird migration is tricky to understand, and Mike Patterson's project at the Neawanna Wetland Ecological Observatory is designed to discover whether these tiny but hardy creatures really do migrate in response to the availability of certain flowers, or whether there are other factors involved. Learn more about his study at the Hummingbirds and Flowers page.
The map data points for this week show the Ketchikan, AK, hummer report, but don't show any reports at all between southern British Columbia and Ketchikan. Do you think this is because no Rufous Hummingbirds appeared anywhere between Squamish, BC and Ketchikan, AK last week? Or is it more likely that no one living in that long stretch has reported their sightings to the Hummingbird Project? Peak migratory movements normally take place between the last week of March and the first week of April, though the Alaska report is the only new report for the week of April 1-8. If YOU see a Rufous Hummingbird, make sure to report it!
A Partnership That Works
Then come back and answer:
Last time we ended our photo safari with the babies at five days old in Dorothy's maple tree. Today we continue the adventure up to 11 days of age when they're stuffing the nest to the max. Please remember to click on each photo for facts and details to help you answer the Countdown Challenge Questions. (NOTE: When you click on each photo, you'll also see some comments and the question.) Here are this week's photos and questions:
Home Tweet Home!
Wow! Just looking at these hummer nest photos makes you wonder how these tiny birds build nests to fit their needs. For a hummingbird to keep her babies alive until they fledge, her nest must provide insulation to hold the mother's heat tightly against the eggs, and to keep rain and cold air from leaking in. It must be a strong bed for the mother to spend all her time while she's incubating the eggs. It must be a stretchable crib big enough to hold two nestlings that are quickly growing as big as their mother. It must be a soft baby blanket to rest on without any sharp points that could puncture or crack an egg. And it must provide a camouflaged hideout that predators can't easily find. Here's an activity that challenges you to find and use materials to build a hummingbird nest that can serve all these purposes. (You'll be glad to know that the nest YOU build can be big enough to hold two chicken eggs!) For nest-building directions, tips on how a hummer chooses a good nest site, and more, see:
Rufous Hummingbirds Heading Uphill: Discussion of Challenge Question #8
Last time we asked,"Why do you think Rufous hummingbirds arrive so much later in the Coast Range and foothills of the Cascades than they do in the Willamette Valley?"
The Coast Range and Cascades are mountainous areas, and at higher elevations the temperatures are colder. (In fact, for every 100 m in elevation, the temperature drops 1 degree C. For every 250 feet, it drops 1 degree F.) Not only do hummingbirds prefer warmer temperatures, but plant development is slower at cold temperatures, too. This means the hummingbird habitat is ready earlier in the Willamette Valley than it is at higher elevations.
Discussion of Challenge Question #9 Through #14
Because we're asking so many challenge questions in connection with the Countdown photos, we are placing the responses to those questions on their very own Web page. Then you can refer to them whenever you are ready to discuss the answers. Here's where you'll find the discussion of Countdown Challenge Questions #9 through #14 from our March 29 report:
Rufous Hummer Homework: Discussion of Challenge Question #15
Journey North got a very complete answer from Carolyn Titus, who compiled the official bird list for the Red Rock Audubon Society. Carolyn says there are eight different hummers that have been recorded in southern Nevada:
J. R. Alcorn's "The Birds of Nevada" is a good source of information on
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: firstname.lastname@example.org
2. In the Subject Line of your message write: Challenge Question #16 (or #17 or #18 or #19 or #20).
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 26, 2001.
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