October 15, 2008
By Susan Benson,
CNHM Director of Education
What do birds do on a rainy, overcast day in October? I found out this weekend on a bike ride. Almost every day this fall I have gotten outdoors on my bike for a ride along the Namakagon River. Last Sunday, the maples were at peak. This week the aspens were at peak. Today, the maple I’ve watched change colors daily, was barren of every single leaf. Each day I stop along the route some place to make new observations. During this week’s bike ride, I watched and heard two bald eagles, an adult and juvenile calling; heard their wing beats above my head; and watched the adult fly swiftly and impressively as it followed along the Riverway. Slate-colored juncos were madly darting after each other through the brush. Black-capped chickadees and white-breasted nuthatches were flitting about. White-throated sparrows and many warblers were also foraging along the river.
Earlier in the week I was astounded by the numbers of migrating robins. They were everywhere, flying through the river valley, but in many other places around the region as well. I stopped long enough to find their favorite places, and discovered a chokecherry tree that had been almost completely stripped of all berries – in its upper branches the fruit stalks were empty. It was evidence that as our ground chills in the fall, robins do adapt their diet away from earthworms and more towards berries.
Robins form loose flocks for both feeding and flying during migration. By traveling in greater numbers, they are more able to notice predators and warn the others. Another advantage of their large flocks is that some individuals who have more experience and familiarity with an area can show others feeding or roosting areas. Their migration is patchy, with individuals spread throughout a bigger range to ensure that they will not deplete available food sources. Robins migrate mostly during the day, although move occasionally at night. They can fly up to 36 miles per hour, so can accomplish up to 200 miles per day. Robins often move ahead of warm fronts, arriving just before or along with rainy weather. Mixing these high pressure systems with northwesterly winds are good conditions for migration.
Migrate yourself outdoors this coming week, and enjoy all that fall still has to offer!
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its new facility in Cable at 13470 County Highway M or on the web at http://www.cablemuseum.org/ to learn more about exhibits and programs.