Zugunruhe. Do you feel it too? It means “migratory restlessness,” and it’s normally used to describe the behavior of birds and other migratory species as they prepare for their long journeys in spring and fall. (It’s pronounced “zoo gen ROO ha” — or at least that’s as close as I’ll ever get to pronouncing a German word correctly.)
Humans are obviously not migratory species, but as a birder, I experience something similar to Zugunruhe each spring as I anticipate the arrival of the birds from their southern wintering grounds. I get antsy if I have to spend too much time indoors, unable to be out searching the skies and the trees for the first signs of birds returning from the south. Along with thousands of other birders, I begin reading the weekly “Birdcasts” from Cornell Lab of Ornithology (here), and watching radar images of birds taking to the skies each night across the continent. This image is from last night:
The blue circles are flocks of birds lifting off to head north. Isn’t that the coolest thing you’ve ever seen? If you’d like to read more about using radar to see birds, David La Puma has a great explanation on his Woodcreeper blog, here. And if you want to check the radar yourself, go here around dusk and keep refreshing your screen to watch in real time as the birds lift off. Just remember to watch for the “blue donuts.”
Some of the migrants have already started to arrive here in Michigan — the Red-winged Blackbirds, Killdeer, Turkey Vultures, and even the Tree Swallows. In a few short weeks we’ll begin finding the first warblers, signaling that it’s time for me to migrate to the southern shore of Lake Erie to witness the amazing congregation of my beautiful avian friends at Magee Marsh. (By the way, if you’re planning to attend the Biggest Week in American Birding this year, you should know that we’ve sold out virtually every space in all of the field trips already, but there are still spaces available in the educational workshops and presentations each day. And you can walk the Magee Marsh boardwalk for free, so if you’re ready for your world to change forever, come and see what all the fuss is about. You’ve got to do this at least once in your life!)
I want to share a bit of migration trivia with you today, to remind us all of the enormity of what these birds do twice each year. It’s mind-blowing when you think about it.
Migration Mania Trivia
- The longest known bird migration is by the Arctic Tern, which can travel up to 25,000 miles per year in its two migrations. It flies from the Artic to the Antarctic and back, crossing the entire planet each year!
- Some individuals of the tiny Blackpoll Warbler species, who weigh only half an ounce, fly a 1600-mile nonstop journey across the Atlantic Ocean from eastern Canada to South America. See, I told you this would blow your mind! You can read the fascinating details of the newly-published study here. (Hint: They put light-sensing backpacks on the birds to determine their flight paths.)
- Before embarking on their journeys, birds experience hyperphagia, a period of nonstop eating designed to put on body weight. Some birds actually double their weight before the trip and burn off all the excess fat before finally arriving on their breeding grounds, exhausted and starving.
- Raptors, swallows, and waterfowl migrate during the day. Songbirds generally migrate at night. This may be because they need the daytime to feed and replenish their energy; conveniently, it may also help them avoid many predators–like raptors–who migrate during the day.
Birds aren’t the only animals that still migrate–whales also migrate twice each year. And many insects migrate as well; the best-known insect migration is that of the monarch butterfly. But the monarchs that winter in the mountains of Mexico will not make the journey more than once. On their way north in the spring, the females stop to lay eggs on milkweed plants as they travel. Some of the adults will make it all the way north, but most will die along the way. The next generation emerges from their eggs and continues northward. When you see a monarch with tattered wings early in the season, that’s probably one that wintered in Mexico. The newest generation will have fresh, untorn wings. According to MonarchWatch.org, summer generations only live two to five weeks; the last generation of the summer is the one that migrates to Mexico, and that generation can live for eight or nine months.
Some large land mammals still migrate in Africa, but the only remaining one I know of in North America is the elk. Many thousands of them migrate each year in and around Yellowstone National Park. Most other land mammal migrations on this continent have been disrupted by the ever-expanding human population and our need for homes and roads.
I hope you learned something from this, as I did while writing it for you. Now get outside and tune in to the wonders of bird migration! See you on the trails….