Think about how long it would take you to walk from Argentina to Alaska. According to Google maps it would take around 90 days walking 24 h/day. Thrushes are long-distance migrants, that means that every spring and every fall they migrate long distances,for example from Alaska to South America and back. So I wondered, how long would it take a Thrush to fly from South America to Alaska?
To answer that question, I asked the expert Emily Williams who worked for the Denali National Park studying Swainson’s Thrush (Name in Spanish: Zorzal de Swainson). She said that one of their birds went from Argentina to Alaska in only 3 months!!! And that’s only flying at night, songbirds rest through the day during migration. How does she know this? With the Denali National Park and Preserve Critical Connections Program, she put small tags on them, released the birds to let them fly to South America, and re-capture them when they are back in Alaska.
The same Swainson’s thrush that you might see in Michigan during migration or during breeding season in Northern Michigan, will be seen by someone else in South America and the only thing that will be different is their name, now Zorzal de Swainson. My personal favorite from Latin America is the Aztec Thrush (Zorzal azteca or Mirlo pinto). You can see this beautiful bird from Southern Arizona to El Salvador, and it is easily seen in the forests of Mexico.
Thrushes and their beautiful songs
The first time I saw a Swainson’s Thrush at the Intermountain Bird Sanctuary, I was not very impressed, honestly. After working with so many colorful songbirds, seeing this larger bird that is not very striking wasn’t the most exciting animal to work with. What made me love Thrushes and birds related to them, like the American Robin, was their songs. Walking in a forest while these birds are singing is one of the most beautiful experiences. I highly recommend you listen to them: Swainson’s Thrush, Wood Thrush (Zorzal de Bosque), Veery (Zorzalito rojizo), and American Robin (Zorzal robín). I bet you have heard American Robins singing in the spring. They were the birds that made me feel welcome in the United States because their song reminded me of the European blackbird (Mirlo). European Blackbirds used to sing on top of the bus stop while I was waiting to go to school. Emily Williams now studies American Robins at Georgetown University in Washington. In one of her recent studies she discusses that Robins that breed in Alaska migrate all the way to Texas but the birds that breed in the Washington DC area don’t migrate at all. Why do you think some individuals migrate and others decide to stay in the same place year round?
How do they make those beautiful songs?
Please check out these animations that explain how birds sing. Birds like the Wood Thrush make some of the most complex songs a bird can create. To do it, they have to pair timed breath control with independent muscle movements (The Cornell Lab). I suggest you sign up for Birds and Coffee Chats with the Kellogg Bird Sanctuary. On March 9th they will talk about Thrushes and how to identify them, it’s virtual and free!
Other than being long-distance migrants and having some of the most beautiful songs, did you know that birds like the Veery are known to predict hurricane seasons? I know, crazy! A study that collected clutch size data from 2003 to 2014 discovered that when Veery birds have a short breeding season tropical storms will be more severe than when they have a long breeding season. Having a short breeding season lets them start their journey from Northern US and Southern Canada to South America (mostly Brazil) early to give themselves some extra time waiting for any storm to pass before crossing large areas of water.
Elizeth Cinto Mejía is a Ph.D. candidate in Michigan State University’s Department of Entomology who conducts research at W.K. Kellogg Biological Station. She is a 2021-22 Science Education and Outreach Fellow at KBS.