American Robin Migration Update: March 14, 2000 Today's Report Includes: Today's Migration Maps and Data Robins Carrying The Tune Northward Reminder: Early Bird Contest: Challenge Question #3 A Day in the Life of a Migrating Robin Fly By Night: Challenge Questions #8 and #9 Where is Buddy? Pig Out! Response to Challenge Question #6 The Eyes Have It: Discussion of Challenge Question #7 Today's Migration Maps and Data Reports of migrating robins are flocking into Journey North Headquarters! Look at today's two migration maps. Of the 3 methods for tracking robin migration, which do you think shows the clearest pattern? First robin SEEN, first robin HEARD, or WAVES of migrating robins? FIRST Robins and WAVES of Robins Dates Robins First HEARD Singing Links to Data FIRST Robins and WAVES of Robins First Robins HEARD Singing Please report to Journey North when you see and hear robins in your hometown! Robins Carrying the Tune Northward Robins are now singing as far north as Edmonton, Alberta and Prince George, British Columbia. When do you think they'll be heard in Anchorage, Alaska? The students at Sand Lake Elementary are watching and waiting for the first robin--and they're waiting for your entry in the... Early Bird Contest Challenge Question #3 "When do you think the first robin will be spotted in Anchorage, Alaska (61.22 N, -149.90 W)?" (To respond to this question, please follow the instructions below.) A Day in the Life of a Migrating Robin Do you live in an area still waiting for robins? What are the robins doing as you wait for them to arrive? Of course you know they're flying. A robin's whole body is urging it to establish a territory, mate, and raise babies--but robins can't start until they reach their breeding grounds. So what's a day like for robins still flying northward? Come along for the ride! Migrating robins stay in flocks, which is one good way to tell if a robin you're seeing is a migrant headed farther north or a robin that is going to stay. When cold weather holds them back, robins spend their days searching for food and eating as much as they can. Robins eat a lot of food, especially during migration. Their bodies must get as fat as possible to allow them to fly long distances without stopping. Luckily, bird bodies are made to store fat in a healthy, efficient way. If the weather is warm and migrating conditions are right, the flock will head in a northerly direction. But if robins suddenly spot a promising-looking field, they'll land for a snack break. If the weather is too cold for migrating, they'll search for likely fields where they can find food in more of a circular area where they land. Sometimes, if the weather turns very cold, they'll actually head south again in their search for food. All day long the flock eats and moves about restlessly. When night comes, the robins sleep. Then one night, when the weather has been just warm enough, their stomachs are full of food, and their bodies have lots of fat, the flock REALLY takes off. At night, when robins have trouble seeing shadows, they rise higher to avoid bonking into things. They may fly as high as a mile, although they usually fly lower than that. Fly By Night Challenge Questions #8 and #9 Robins are unusual migrants because they can migrate by day or by night. Many huge autumn migration flights take place in daylight. But in spring, robins often fly by night. After reading about a day in the life of a migrating robin, how would you answer: Challenge Question #8: "Why do you think there is a seasonal difference in the timing of robins' migration flights?" Challenge Question #9: "Robins migrate at a speed of about 50 kilometers per hour. On the first day of spring, when night is exactly as long as day everywhere on the planet, how far might a robin go on its night flight? Look on a map and see if you can guess what town or city or your first robin of spring might have departed the night before." (To respond to these questions, please follow the instructions below.) Where is Buddy? Do you think all robins look pretty much alike? Journey North writer Julie Brophy knows how careful observers can tell robins apart. Julie recognizes her robin Buddy, and hopes to see him for the third year in a row. Will Buddy return in 2000? How will Julie know it's Buddy? What does Buddy show Julie about robin behaviors? Read her story: Link to: Waiting for Buddy Pig Out! Responses to Challenge Question #6 Last time we said how much food baby robins eat. We asked, "How many pounds of food would YOU have to eat in a 12-hour period to comprise 150 percent of your weight?" Your answer will depend on your own weight, but these two students are probably glad they aren't baby robins! First to answer was Bryan Young, who said: "I weigh 160 lbs., so I would have to eat 240 lbs. of food in a 12 hour period." Joey Cristalli figured how much food he'd eat per hour: "I would have to eat 25 pounds of food an hour for 12 hours because I am 200 pounds." The Eyes Have It Discussion of Challenge Question #7 Last time we asked: "If you had the materials Frank Heppner used, how would you design experiments to prove which sense(s) robins use to find worms? Why do you think he used each of these materials?" Pieces of dead earthworm Living earthworms Rotten eggs Decaying meat Rancid butter Mercaptoacetic acid (which smells like a cross between sewer gas, rotten cabbage, a skunk, and a stinkbug) A small drill A tape recorder that was extremely sensitive at low frequencies Dr. Heppner considered ALL the senses that a robin might use to find worms. TASTE: NOPE! Robins would have to taste a LOT of dirt to pick out worms this way! SMELL: Dr. Heppner recorded that "robins nonchalantly ate foods smelling like rotten eggs, decaying meats, rancid butter, and the absolutely worst smell of all bad smells, mercaptoacetic acid." He concluded that robins don't seem to notice nice wormy smell at all! TOUCH: If robins feel vibrations of live, wiggly worms, they wouldn't bother eating still, dead worms. But when Dr. Heppner drilled worm-like holes in the ground and placed dead worms in them, the robins found and ate them readily! HEARING: Using VERY sensitive recording equipment, Dr. Heppner taped the low-frequency sounds made by burrowing earthworms, and found that the robins ignored the sounds. SIGHT: Robins look for earthworm holes that have a worm within visual range. When Dr. Heppner drilled holes that looked exactly like wormholes, robins ignored them UNLESS a worm was in them. Whether that worm was alive and normal, alive but coated with a bad-smelling odor, or dead, the robins found and ate it. 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-robin@learner.org 2. In the Subject Line of your message write: Challenge Question #8 (or #9). 3. In the body of each message, answer ONE of the questions above. The Next Robin Migration Update Will be Posted on March 21, 2000. Copyright 2000 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form