The Mystery of Migration
Ashley Reed- Emmet County Naturalist
There are many things to look forward to as we transition into our next season. The leaves start to change from crisp green to vibrant oranges, crimson and golds. Mother Nature takes her paintbrush and fills the landscape with warmth. The leaves inevitably fall to the ground and they crunch under your shoes as you walk through the woods. Inhale. The cool air along with the freshly fallen leaves fills you with an aroma that is indescribable but brings comfort at the same time. Fall brings us football, bonfires, apple orchards and pumpkin patches- but for animals, fall has a much different meaning.
Now that I’ve got you thinking of the changing of seasons, I thought I would talk about one of nature's most fascinating phenomena. Let’s talk about migration. Every year many animals make strenuous journeys across the country, some across continents! For the article's sake, I will only be focusing on migration as it pertains to Iowa, but I highly suggest watching documentaries on the subject that can be found on many streaming services.
So why do animals migrate? Typically in Iowa, many animals travel north to the midwest to breed during the spring and summer months. When fall rolls around they head south once again to beat the cold weather and follow the food. Many think that the animals leave when the temperatures start to drop but in reality, their bodies tell them when it’s time to go. Animals have a very strong biological clock that runs off daylight. They know when the days are getting shorter that it is time to make their next journey. Trees and plants have this clock as well! Every species clock runs a little differently, so we have early migrators such as Blue Winged Teal whereas other waterfowl migrate much later in the season. So not only do they know when to leave and return every year, they know exactly where to go. Many of these animals return to the exact same place year after year. Monarchs, for example, return to the same forests in Mexico every single winter. With monarchs, it takes a couple of generations to finish the full migration, meaning that the butterflies arriving in Mexico know precisely where to go without ever making the journey before! Meanwhile, I’m lucky to make it to the grocery store without getting lost.
When we think of animals that leave us during the fall and winter months, birds typically come to mind. Many of our songbirds such as the robins, goldfinches and orioles say goodbye and leave for warmer weather. My personal favorite migrating bird we have are hummingbirds. The Ruby-Throated Hummingbird weighs in at 0.1 to 0.2 ounces and flys with a wingspan of 3 inches. They come to Iowa during the summer months to breed and their summer range extends up into Canada. When it comes time to fly south, these tiny birds fly down to Central America! They have to fly across the Gulf of Mexico to complete their journey. How incredible is that?
You still have some time to observe our migrating friends before they leave for their winter vacation, so enjoy them while you can. One of the reasons I love nature is that from a glance, it all seems so simple. Find a butterfly and appreciate the beauty that went into creating them, but then you realize how complex and evolved even the smallest of creatures can be.