Fall's Journey South

Fall's Journey South Update: October 30, 1998

Today's Report Includes:

Robins Moseying South

Robins easily survive in winter if they have food

Robins have been migrating since August, yet a few are still in the far north. Every spring robins rush to their breeding grounds, but in the fall there's no reason to hurry. They mosey on south eating crabapples and berries, and gather in flocks both for feeding and roosting. Doug Fahrendorff's fifth graders at Hillcrest Elementary School in Ellsworth, Wisconsin (44.7N, 92.5W) wrote Journey South that "On Friday [October 16, 1988] students in my class saw three robins huddling together near the bike racks to protect themselves from the cold." Some groups of robins are small, but some may be huge. Not all that far from Doug's school, also in Wisconsin, on October 15, 1998, people noted roosts of 5300 near Tomah (44N, 90.5W) and 3000 near La Crosse (43.8N, 91.3W). How could anyone count so many? What do you think the margin of error in this kind of count is? Do robins roost near your city or town? Try to count them!

First Place Is Easier than Last

Robins may come to feeders in fall.

It's easy to recognize the date when the first robin arrives in spring. The date the last robin leaves in fall is a lot trickier because you can't be sure one really was the last one until you've gone weeks without seeing another, and by then it's easy to forget when exactly that last one was seen.

One excellent way to keep track of the phenology of birds and other animals requires nothing more than graph paper. On the first day of each month, start a new sheet. Along the long axis, list the numbers from 1-30 or 31 (the number of days in that month). Along the short axis, list each species you notice. Put an X in the corresponding box for each date you see it. At the end of each month, some common species may have a LOT of X's! Over time, you will have an accurate record of the phenology of your area, and will be able to clearly see the first and last dates that each species is around for that season.

Do You Know This Robin?
When robins start moving, how do you know which ones are your "own" local robins and which are migrants? It's usually impossible to tell unless they have been banded or color-marked, except for one lucky thing. Male robins from Newfoundland and Labrador are darker than other robins, with almost black backs, brighter red underparts, more noticeable striping on the white throat, and a bolder eye-ring. People farther south in Canada and the U.S. may notice the difference when they spot one of these, and then they'll know for sure that these are the northern race rather than their own breeding robins. Many magazine photos of winter robins show these brightly colored ones, which make a lovely contrast against snow-covered branches and orange berries.

Leapfrog!

The Range of the Robin

Some species of birds migrate in a "leapfrog" pattern. This means races from the farthest north breeding grounds migrate to the farthest south wintering ranges, and races from the southernmost breeding grounds migrate the shortest distances. This may be true of some groups of robins, but is definitely not true of the Newfoundland/Labrador race-some individuals of this race stay in the far northern states and southern provinces all winter, so they're definitely not leapfrogging over robins that go all the way down to Guatemala. Robins are so common that ornithologists sometimes take them for granted, and less is known about them than about many rarer species. Maybe you will be the one to figure out some of the mysteries about this common but mysterious bird! You can get a start by considering this week's

Challenge Question #9
If you were an ornithologist trying to figure out whether robins have a leapfrog migration or not, how would you set up your study? How would you keep track of individuals?

Dessert First!
Throughout the year, robins eat whatever food they can find, but there is a seasonal change what they find most easily. In spring and summer they concentrate on insects and earthworms, but as berries and fruits ripen in late summer, their diet changes. Robins, waxwings, and other fruit-eating birds often eat the sweetest berries first, leaving the more sour or bitter ones till the best ones disappear. American elderberry and Nanking cherry are so sweet when they ripen that many people call them "ice cream plants," while others don't taste good until they have frozen and thawed several times, like bittersweet-one of the "spinach plants."

Take a walk around your school or backyard hunting for berries that are still hanging on trees. Can you identify them? Your library will have field guides to trees and shrubs that might help. Are any birds feeding on them?

Unpave the Way for Robins
Migrating and wintering robins need a lot of calories to survive. One way you can make a big difference is to plant the trees and shrubs that they need most. Fall is a good time to plant-garden stores often have good prices, and many of these plants do best with a fall planting. Here are some plants that provide nourishing berries or fruits for robins. Your local greenhouse or plant store will know which grow best in your region, and may have more suggestions for fruiting plants.

	Flowering crab Chokecherry American elderberry Wild plum Raspberry Serviceberry	Cherry American plum Pin cherry Mountain ash American highbush cranberry Virginia creeper
Providing plants to feed robins in fall and winter will help keep them singing when spring returns

Migration route of Peregrine Falcon #5735

Discussion of Challenge Question #8

Adding up all the distances between areas that Peregrine #5735 travelled, we at Journey North came up with about 5770 km, or about 3460 miles. However, it was tricky making these measurements, because it required the use of several maps, all drawn at different scales. The Peregrine must have actually flown much farther than this, because each measurement was "as the crow flies" from one spot to another. Peregrines usually follow rivers and shorelines, and occasionally circle, backtrack, and zigzag while hunting.

How to Respond to Today's Challenge Question:

1.Address an e-mail message to: jn-challenge-fall@learner.org
2.In the Subject Line of your message write: Challenge Question # 9
3.In the body of the message, answer the Challenge Question.

The Next Journey South Update Will Be Posted on November 6, 1998

How You Can Help Track Fall's Journey South
How You Can Help Track Spring's Journey North