Signs of Spring Update: May 3, 2002 Today's Report Includes: Red-winged Blackbirds Setting Up Housekeeping: Challenge Question #27 Redwing Migration Map Neighborhood Watch: Link to Lesson and Challenge Question #28 Fun with Redwings! Oriole Migration Push: Discussion of Challenge Question #24 Day vs. Night: Discussion of Challenge Question #25 Oranges: Discussion of Challenge Question #26 Year-End Evaluation: Please Share Your Thoughts! Red-winged Blackbirds Setting Up Housekeeping Red-winged Blackbirds are nesting in most places in their breeding range now. But some are still migrating, thanks to the late snow and cold weather in many places. In Duluth, Minnesota, some redwings are already building nests and even laying eggs. In the exact same city, others are visiting feeders and biding their time before continuing their migration farther north. Why do you think the redwings that are still migrating aren't hanging around in marshes? Challenge Question #27: "Why would migrating Red-winged Blackbirds be found in different habitats from nesting ones?" (To respond to this question, please follow the instructions below.) Redwing Migration maps from March 8, 2002 and May 2, 2002. Click here for Red-wing Migration Data from May 2, 2002 We've put this week's migration map on the right to compare with the migration map from March 8. Of course the birds are much farther north now! But notice something else. There have been many "first sightings" in recent weeks in the same general areas that there were several weeks ago! Even though the earliest blackbirds reach some places quickly, it often takes weeks longer for them to get to nearby spots. Some places are in low-lying or shaded areas that stay frozen a bit longer or don't produce food as early in the season. So the map shows not only progress north, but also an important filling in of gaps. Neighborhood Watch! Once redwings set up housekeeping, they have to ensure that their babies will be safe. One of the ways they do this is with a kind of "neighborhood watch" program. When male redwings are perched on their cattails, they keep watch not only on other redwings crossing the boundary to their own territory, but also on any crows or hawks that happen to be flying over. If a redwing spies a crow or hawk, it takes off to attack! Learn more about this interesting behavior at Neighborhood Watch Then answer this question: Challenge Question #28: "Why do you think crows don't fight back when a redwing attacks in the air?" (To respond to this question, please follow the instructions below.) Fun with Redwings! Red-winged Blackbirds like wetlands with cattails. Many highways in the United States and Canada are drained by running along ditches. When these ditches fill with water, they become good habitat for redwings. That's why we so often see Red-winged Blackbirds while we're riding in cars. The birds can feed on seeds blown to the side of the road, and they often perch on power and telephone lines to get a better view of their entire territory. Next time you go on a long car ride, ask the driver to keep track of the miles for you, and count redwings for a while. When you get tired of counting, calculate how many redwings per mile there were. If someone is riding with you, one can keep track of redwings on the left side of the car while the other keeps track of them on the right side. Make it a contest to see who can spot more! You can find more fun activities with redwings, including our special Red-wing Action Figure Activity, at: Red-winged Blackbird Field Studies You Can Try Oriole Migration Push: Discussion of Challenge Question #24 Last time we asked, "Why do Bullocks Orioles always have a big migration push weeks before Baltimore Orioles do?" Look at their range maps. Notice that Bullock's Orioles winter in Mexico. When they migrate, the shortest route is straight over land to their breeding range. Once days are growing a bit longer and they're starting to become migratory, they can simply head out when the weather seems good. The weather stays fairly mild all along the West Coast, so even if they come up in February or early March, they aren't going to be hurt. Now look at the range for Baltimore Orioles. Most of them winter in Central America and even South America. The shortest distance for them is to cut over the Gulf of Mexico. When they strike out over that huge body of water, they have no way of knowing what the weather will be like on the other side. So they wait until late enough in the season to be reasonably sure that there will be food and reasonably good weather before they even leave. Day vs. Night: Discussion of Challenge Question #25 Last time we asked, "Why do most orioles migrate by night?" Let's think about the advantages and disadvantages and you'll see why: Night Advantages Night Disadvantages Day Advantages Day Disadvantages 1. Cooler temperatures better for lots of flapping 2. No hawks 3. Less wind usually 4. Can only eat in the daytime, so can use the whole night for flying 1. Must stay high because orioles can't see well in the dark and don't want to bump into anything 1. Can see better 1. Sun and warmer temperatures can make them get too hot when flapping 2. Hawks 3. More wind Oranges: Discussion of Challenge Question #26 Last time we asked, "During migration orioles often visit feeders for oranges. But by the end of May, orioles seem to lose their taste for oranges. Think of at least two reasons why orioles seldom eat oranges in summer." Oranges are rich in sugars and vitamins, but don't have much protein. They give a lot of energy for migrating. But by the end of May, orioles are mostly done migrating and are starting to nest. For females to form eggs in their bodies they need a lot of protein. And growing baby orioles need a lot of protein. So the parents start focusing more on bugs than fruit. Also, orange trees don't grow in most of the oriole breeding range. By late May, there is plenty of natural food around, and orioles aren't as interested in feeders at all! Year-End Evaluation: Please Share Your Thoughts! Please take a few minutes to share your suggestions and comments in our Year-End Evaluation Form below. The information you provide at the end of each year is the single most important tool used to guide our planning. Year-End Evaluation 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-spring@learner.org 2. IMPORTANT: In the Subject Line of your message write: Challenge Question #27 (OR #28). 3. In the body of the message, give your answer to the question above. The Next Signs of Spring Update Will be Posted on May 10, 2002 Copyright 2002 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form