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Hummingbird
Migration Update: February 24, 2005
First Rufous Hummingbirds Reach Puget Sound (WA) Mike Patterson sends news on the Rufous migration from his study site at Oregon's Neawanna Wetland Ecological Observatory. In 17 new sightings, this week brought the first Rufous Hummingbird reports from Puget Sound, WA. A couple of Arizona sightings and also a few females were reported too. In which states do you see Rufous sightings? Which state has reported the most sightings? What do you notice about location of most of the Rufous sightings? Where do you think they'll go next? “Unlike the hummingbirds,” says Mike, “the flowers are on right on time.” Mike's research project tracks the movement of hummingbirds and the availability of flowers that provide nectar. In flower news, Mike spotted the first Salmonberry (Rubus spectabilis) blossoms Feb. 21. (As for the timing of the hummingbirds, you'll read more in the answer to Challenge Question #1, below.)
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! Telling a Rufous from other kinds of hummingbirds can be tricky, so here’s how to know what you are looking for:
In 2003, Mike Patterson went through his data on quantifying the amount of green on the backs of Rufous Hummingbirds. He 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)," said Mike. He 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? How does this photo show support of Mike’s data? Read on for more about this little Rufous hummer. An Unusual Early Bird: Jackie’s Rufous Hummer Rufous hummingbird migrants normally start passing through Jackie’s area in California at the end of February. They normally don’t stay long at their stopover spots during the northward migration. This January 24 arrival is still at Jackie’s as of February 23! Why? The answer might be visible to you in this pair of photos. Look closely to see how the two are alike and different. What do you notice?
Feather Phases: Challenge Question #2 Did you notice the difference in the throat feathers? The shiny feathers on a male hummingbird's throat are called the gorget. The gorget on a Rufous hummingbird is a beautiful reddish-bronze color. Why does the Rufous on the right have so much white in the gorget? The bird is molting, which means losing old, ragged feathers and growing new ones to replace them. Feathers eventually wear out, so at least once a year birds replace all their feathers with new ones. But don’t expect to see a bunch of balding birds. Most species lose only one or two feathers at a time so they can still fly. Next time we'll share more photos of Jackie's molting Rufous, and more fascinating details she has observed. But for now, send us your thoughts:
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In both 2003 and 2004, the first Ruby-throated hummingbird reported to our data source and expert Lanny Chambers was sighted on February 25. So far, no arriving migrants have been reported, but they must be getting close! This species usually starts arriving around the third week of February in states along the Gulf Coast. Folks in LA, MS, TX, GA AND FL--are you getting your feeders ready? Expect more Ruby-throated hummingbird news in our next report. But ponder this while you wait: Journaling Question: Why do you think Rufous hummingbirds are able to begin their journey north so much earlier than Ruby-throats? Staying Alive on Cold Nights: Link to Lesson 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 weigh more than you!) How can the season's early hummers -- the tiniest of all warm blooded animals -- possibly survive when they go to sleep at night? Luckily, hummingbirds have a special adaptation that helps them survive cold nights; they turn down their body temperatures in a process called torpor. Discover more, and learn with help from modeling clay, a balance, thermometer, and refrigerator:
Ruby-throated hummingbirds often migrate over the Gulf of Mexico, flying over 600 miles non-stop because there is nowhere to land. How are their wings adapted to help them? You learned about the adaptation of torpor above; now learn about many more! A Tricky Prediction: Discussion of C.Q. #1 On January 31 our Rufous hummingbird authority, Mike Patterson, predicted that first arrivals will be late this year, because of nasty weather to the south. Mike based his prediction on the weather at the time. On Feb. 8, he was astonished when his own first Rufous arrived! We asked you: “Why might some Rufous hummingbirds be arriving this year much earlier than expected? Explain why you think so.” Joe and Katelyn think that the Rufous hummingbirds would be coming back early because of the warmer weather this time of year. Jeremiah M. thinks it’s the weather, too. He said, “If the hummingbirds migrate down to the deep southwestern United States and Mexico where all of the rain and thunderstorms are, then they must be smart enough to realize that the weather is nice up here. ” But is there more to it than the temperature? Consider these other suggestions by Journey North’s bird expert Laura Erickson:
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