Spring is finally upon us, and the flowers and trees are beginning to bloom again. Every spring we also see the return of many of our favorite feathery friends, but how is it exactly that birds know when to fly home or even how to get there? Bird species come and go throughout the year and seasonal changes and different areas will have unique bird migrations specific to that particular area. Here are a few fun facts about the journey home for many beautiful birdies.
Each Journey is Unique
Every species of bird will have their own unique travel itinerary, including different departure and arrival dates as well as stops they plan to make along the way. Some species will make this journey alone, while others fly in large groups or flocks. Some of these birds will fly much further than others, and many of these trips can be longer than you’d imagine.The Arctic Tern holds the record for the longest migration with distances averaging up to 44,000 miles per year! Birds mainly migrate in search of food, better weather, or for breeding purposes.
Time to Go!
So, how to birds know when it’s time to go? Do they set a tweety-bird alarm clock that lets them know it’s time to pack up and head out? As food supplies dwindle, birds know it’s time to move on but many will leave even before this happens. Scientists have discovered birds know it’s time as temperatures and the length of daytime changes as it affects their hormones. Springtime is when many bird species feel the natural pull to leave, which some of us can relate to as well! As their hormones change, they can stock up on fuel for the journey and their bodies will allow them to gain weight and stock these extra reserves quickly. Prior to takeoff, many species will have their digestive systems shrink and will not eat again for days.
Which Way Do Birds Go?
Now that they know it’s time to head out, how do they know which way to go? Birds are pretty clever little creatures, and they have their own unique set of tools they use to orient themselves with their surroundings. They use the sun in order to determine direction and time of day, as well as the moon and stars for direction. Scientists have proved this theory by letting birds fly in a planetarium and changing the stars’ position. Birds also use earth’s magnetic field to find magnetic north which helps them navigate. Of course, like us, birds remember specific features of the landscape like mountains and rivers to locate where their favorite places are.
Like we mentioned above, some species will fly straight to their migration and breeding grounds while many other will stop along the way. The species who just can’t wait to get there will often fly through the night and over periods of days without stopping to eat or sleep. The Ruby-Throated Hummingbird will fly 560 miles nonstop clear across the Gulf of Mexico. That’s quite an incredible feat for such a tiny bird! These birds have been know to consume energy at around eight times their resting metabolic rate. Just imagine working out at the gym for days and days without eating or sleeping!
Birds Just Know
There’s still mystery surrounding some of the unique aspects of bird migrations. Each bird seems to have it’s own special biological clock that lets it know when it’s time to move. Studies have shown birds kept in captivity during migrating season will show signs of Zugunruhe, or migratory restlessness. They will try to fly in the direction of their migration destination. Any birds that are exposed to unnatural daylight at odd intervals will not experience this, further proving birds take cues from their environments. There are even some types of shorebird chicks who’s parents will migrate to the southern hemisphere before they are ready to fly. Once the chicks develop their wings they take off on a journey they have never been on, over land they’ve never even seen and seem to just instinctively know which way to go.
Our feathery friends are a delight when they show up in our backyards and along our favorite trails and streams. Springtime is a favorite time of year for all of nature, and of course for us as well. Next time you see a beautiful Hummingbird or a Swallow hanging out on your porch, consider the incredible journey they may have taken just to get there!