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Hummingbird Migration Update: April 29, 1999
Today's Report Includes:
- Hummers Arrive in Northern States!
- Ruby-throated Hummingbird Migration Data
- Rufous Hummingbird Migration Data
- Challenge Question #12
- Migration Strategies
- Challenge Question #13
- Time to Set out Feeders
- Discussion of Challenge Question #11
- How to Respond to This Week's Challenge Questions
Hummers Arrive in Northern States!
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The first Ruby-throated Hummingbirds are back in Minnesota and Wisconsin. Each one of these tenth-of-an-ounce migrants has flown across the Gulf of Mexico entirely on its own. People used to believe that hummers rode on the backs of geese for at least part of their journey, but now scientists know that they don't.
Challenge Question #12
"How would you design an experiment to prove that hummingbirds really do migrate on their own power?"
(To respond to this Challenge Question, see below.)
Migration Strategies
More Rufous Hummingbirds are arriving in Idaho as they reach an important point in their migration. The very first hummer reported from Idaho arrived on April 5, 1999, in Cour 'D Alene (47.67 N). But hummers arrived in Petersburg, Alaska, (57.04 N) on March 24, two full weeks before that! And there were several more Alaska sightings before another one showed up in Idaho this week.
Challenge Question #13
"Why did Rufous Hummingbirds appear all the way up in Alaska two weeks before they arrived 10 degrees south of there in Idaho?
(To respond to this Challenge Question, see below.)
Time to Set Out Feeders
If you haven't done so already, this
is the time to set out hummingbird feeders. Migration surges now, as they reach the final legs of their journey
north. Once they arrive, they will be able to find some natural food, but sugar water feeders give them lots of
energy to be in top condition as they start their critical nesting period.
Discussion of Challenge Question #11
"How do you suppose a hummingbird can get sap from a tree?"
Hummingbirds can't "tap" the tree themselves, but they DO take advantage of other critters tapping! Yellow-bellied Sapsuckers make a ring of small holes around a tree, coming back frequently to feed on the running sap. Sapsuckers protect their holes, but whenever they leave for a while, other birds come in for a sip. Hummingbirds are VERY aggressive, often divebombing and chasing much larger birds away. In areas without hummingbird feeders, the easiest place to find hummingbirds when they first arrive is at sapsucker holes!
How to Respond to Today's Challenge Questions
Please send only ONE answer 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 #12 OR #13
3. In the body of your message, answer the question.
The Next Hummingbird Migration Update Will be Posted on May 13, 1999.
Copyright 1999 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form
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