American Robin Migration Update: April
Latest Migration News: 2 NOP Locations Still Waiting For Robins
Where do you see the dark blue dots of the latest arrivals on this week’s maps? Do you see how the migration is slowing as we get into May?
You’ll know which of our Northern Observation Posts in Alaska and Canada are still waiting for their first robins when you check the chart of our NOPs, below. When will the first robins appear there? As soon as they report, their sightings will show up on the map server and data bank (push the owl button on any Journey North page):
In the meantime, you might enjoy a "cool" snapshot from one of our NOP locations:
Nests in the News
Your observations are full of announcements about the next generation of robins! Here are a few of the exciting reports:
Into the Nest With Julie's Robins
When Journey North's Julie Brophy discovered robins nesting in her Minnesota backyard, she watched and took notes as the parents raised four babies that successfully fledged. You can follow the nesting process and see the robin's growing family, as well as learn lots from questions (and answers) with the photos. We challenge you to look for facts to expand on what each observer quoted in the section above. Don’t miss this exciting adventure with Julie’s backyard Mama robin and her babies:
Fun Math Questions for Your Science Journal
After the photo study above, sharpen your pencil for these answers:
1. What percentage of a mother robin's body weight is her brood of newly-hatched babies? What percentage of a mother hummingbird's body weight is her brood? Do you think this may be related to the reason that robins lay four or five eggs while hummers lay two?
If a robin lays her first egg on May 1 and everything happens
in an exactly average way, what date do you think her babies will fledge
from the nest?
Run, Robin, Run! Video Clip and Activity
If there’s no robin outside your window, watch the robin in this video (in box at right). He is running on the pavement. Notice how he runs a short distance, searches, and runs again. Do you notice him poop? Healthy, well-fed robins eliminate their wastes several times every hour. Robin intestines are much shorter than most mammal intestines, so robins eliminate wastes as quickly as they produce them. Small rodents must do the same thing, as anyone who has ever held a gerbil, hamster, or pet mouse knows! Now you’re ready to view the video clip to see what you can see!
know that robins love worms! Worms have lots of nutritious protein and
valuable calories for robins. But robins round out their diets with food
besides worms. When robins are running on a lawn hunting for worms, they're
also searching for other tasty morsels. They eat beetles, caterpillars,
spiders, and even snails and slugs. All are rich in protein and other
nutrients that robins need for growing strong bodies and new feathers.
Wiggling Off a Robin's Lunch Menu: Investigate Escaping Predation
Worms are up, as you can see on our May 6 map!
Have you ever noticed a robin tugging a worm out of the ground? Worms do NOT want to become bird food, so their bodies have a special adaptation to hang on for dear life to the walls of their burrow. Every segment of a worm’s body (except the first and last) has four pairs of tiny, stiff hair-like projections called setae. Controlled by their own muscle system, the setae act like strong hooks. When a robin or other bird grabs a worm in its burrow, some of the worm’s setae dig in and hold the top end of the worm in place. At the same time, the worm’s other end contracts to move it deeper into the burrow. Thanks to the setae, the birds really have to tug to pull out a worm. And some worms are lucky enough to actually escape the predators by burrowing deeper underground. You might wonder how long it would take for an earthworm to go underground. What variables might affect the time it takes? If you were a worm trying to escape a hungry bird, what would your luck depend upon? Would the soil type make any difference? Use worms to investigate how long it take a worm to get underground in various soil types, and to consider variables that might affect the time it takes. (Remember to place your worms safely back in shaded soil after they’ve helped you with your investigation.) See directions here:
Chow Down: Make a Pie Chart
Baby robins grow quickly--growing from the size of their egg to the size of their parents in only about two weeks! For their first four days of a nestling's life, the parent birds regurgitate partly digested food into the orange, yawning mouths of the babies. By their fifth day, the nestlings are receiving earthworms that have been broken into small mouthfuls. As the days go by, parents give the babies complete worms and large insects. Fred Charles found that Illinois robins put in 15.5 hours a day feeding young in late May, bringing an average of 356 pieces of food daily!
Make a pie chart showing what baby robins eat.
Splish, Splash! Robins Like a Bath
What's the best way to attract robins? Provide water! Few birds bathe as often as American Robins. If you watch them, you'll see how much they enjoy baths. Sometimes several robins line up around a birdbath and wait contentedly for a turn! Whether the water is in a birdbath or pond, robins will drink and bathe whenever water is available.
Who is That Masked Robin? Photo Study/Link to Lesson
If this robin could speak English, it could tell us what caused its strangely fascinating pattern. Since it can’t, we can only make guesses. What are three possibilities that Laura Erickson thought of? Which guess makes the most sense to you? Do your ideas fit with Laura’s? Find out here:
The Robins in Our Backyards: FAQs
Did you know?
Robins show a powerful loyalty to nesting territory year after year, and robins live fairly long lives. One banded individual survived 13 years and 11 months!
People have asked us all kinds of questions about their backyard robins. From Florida to Alaska, California to Newfoundland, robins are familiar backyard birds. People can’t help but notice many of the things they do, and we want to help robins when they’re in trouble. We’ve put together some of the most frequently asked questions about robins with answers from our Robin Expert, Laura Erickson. You’ll find questions and answers full of facts and natural history information to keep you happily learning about robins all summer long! For example…
For these answers and many more, see:
Summer Robin Watching
Now that robins are nesting in many places, see what kinds of observations you can make. During summer vacation, keep a field notebook for recording all your observations. Learn what kinds of things to record here:
Survival Math: Discussion of Challenge Question #9
Last time we said that one scientific study showed that about 75% of all fledgling robins die before November their first year. Of those that survive that long, about half die before the next November. About half of all 2-year-old robins die each year, and about half of all robins of every other age die each year, too. If this is true, and if 200 robins were fledged in a town one year, then:
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.
In the coming year, Journey North will be fundraising to secure increased support from foundations, corporations and individuals. Your supportive comments will be a tremendous help. Thank you!
This is the FINAL American Robin Migration Update for 2004. We’ve had a lot of fun learning about YOUR robins this spring! Thanks to everyone who shared observations as we celebrate another journey north--and three cheers for everyone who will watch their robins with a caring and attentive eye this summer. See you next spring!
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