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American Robin Migration Update: February
17, 2004
Winter Robin Roundup
Results: Here's Where They've Been At this writing, you've told us that robins in February are found from Florida to Canada, with fewer robins in the middle of the continent--where conditions are drier, winter weather more severe, and fewer fruit trees provide food. You've seen waves of robins (groups of 3 to hundreds) from coast to coast, but no waves as far north as individual robin sightings. And a very few robins in 6 states south of the Great Lakes (but none near the coasts) have even been heard singing.
Today's Migration Maps and Data Even with all these sightings, what tells you that very few robins have returned to their summer breeding territories? You'll find the answer in the maps and paragraphs below. We admit that tracking the robin migration is tricky, but that's what makes it so fun!
"We had over 7000 on our annual local Christmas bird count," wrote Ms. Loud from Tenacre School in Wellesley, Massachusetts. "With so many resident robins in winter, can robins REALLY be considered a sign of spring?" Good question! The 3 robin maps help to answer it. How? Today's nearly empty song map shows that robins are not yet defending their breeding territory. Robins returning to breed and nest are indeed signs of spring. And "Song" will be the clearest pattern we expect to see as we track this spring's robin migration. While this map shows WHERE robins were found in early February, it does not show HOW MANY were found at each place. Scientists would say the map shows robin DISTRIBUTION but does not show robin ABUNDANCE. The fact is that, even though robins are already spread across a large portion of their range, we're about to see huge masses of them move across the continent. The abundance of robins is about to shift dramatically from south to north. When they are back on their territories, they'll start to sing! So. . .look to the "First Robins Heard Singing" map for the clearest picture about when and where robins are switching from winter feeding and flocking behaviors to spring migratory restlessness and territoriality. Please see these instructions so you can help to track robin movements this spring.
How can you track the migration if robins are already around? How can you tell the over-wintering robins from the first robins of spring? SONG is the key! Winter robins do plenty of calling and chattering. But when they switch to their true song, the difference will be clear. Remember: "Song" will be the clearest pattern we expect to see as we track this spring's robin migration. Listen to robin vocalizations to help you sort calls from songs:
The robins ringing this bird bath appear to be having fun! In autumn and winter, robins become sociable. They join flocks and feed, drink, and roost close together. Go around the bird bath and look carefully at the body postures of each bird as another robin flies in. What does each robin's body posture tell you? Would Becky Stanton be able to take a photo like this in June or July? There's a lot to learn from this photo with our robin expert as your guide: Then send us your answer to. . .
(To respond to this question, please follow the instructions below.)
Robins in Winter: What You Told Us, and CQ #2
Florida: (Feb 14) "Observed a very noisy wave during misty cold front around 12pm-1pm. Easily hundreds of birds. Very exciting on Valentine's day." Arkansas (Feb 12) "Woke up this morning with approximately 50 Robins in my back yard. They were chirping and frantically eating. They were rather large and looked very healthy." Missouri: (Feb. 10) "We have had, for us, a very cold and snowy past three weeks but this morning we awoke to the chattering and singing of 500 or more fluffed out and cheerful Robins." Kentucky: (February 9) "We have robins overwintering here in Cub Run. Huge flocks of hundreds of thousands have been seen. Also, smaller flocks and individuals have been spotted by our students. We haven't heard any robins singing yet." Alabama: (Feb. 9) "After several days of rain I looked out in my back yard and saw the robins digging leaves looking for food. I felt excited that spring was coming seeing the robins!" Courtney, grade 3 California: (Feb. 1) "Robins first arrived at the beginning of December, as usual, and we have seen flocks of them flying around our neighborhood for the last several weeks, pillaging bushes with berries, hopping on lawns (haven't seen any get a worm yet). Lots of alert chirps but no songs yet." Ohio: (Jan. 16) "There were hundreds of fat males gorging on berries at the North Olmsted library. It was so exciting I shall never forget it. And at the top of a nearby tree was a hungry hawk, head going left to right, too overwhelmed to strike or (haha) too full."
(To respond to this question, please follow the instructions below.)
How to Respond to Today's Challenge Questions:
1. Address an e-mail message to: jn-challenge-robin@learner.org Copyright 1997-2004 Journey North. All Rights Reserved. |
