One of the amazing things about birding around the world is the sense of connectivity you get. I work at Valle Crucis Community Park as the Park Naturalist when I’m not leading birding tours, and the Park has recorded an impressive 182 species of birds. Of those birds 114 can also be found in Costa Rica!
One of the first birds we spotted on our most recent Costa Rica Tour was a juvenile Broad-winged Hawk sitting on a power line. There is a good chance it was one of the tens of thousands of hawks that migrated down the Appalachians this past September, and we might have seen this same bird soaring past Valle Crucis! The many warblers that breed at the Park also migrate to the tropics each winter. I’ve seen Yellow Warblers, Chestnut-sided Warblers, Black-throated Green Warblers, and many others, even some of the rare NC visitors like Wilson’s Warblers, wintering in Costa Rica. It can be a bit of a strange experience to see a mixed flock of tropical tanagers, woodcreepers, and ant-shrikes moving through the rainforest and then notice several Chestnut-sided Warblers in the flock; or hear a rustle in the fallen leaves, stalk the sound to it’s well-hidden source, and realize it was a Swainson’s Thrush that caught our attention!
The idea of migratory birds having a ‘Northern Home’ vs a ‘Southern Home’ has been debated for many years. With modern DNA and genetic research, we have learned that most migratory birds we see in Valle Crucis originated in the northern hemisphere. Over tens of thousands of years, and several ice ages, they began to migrate south for the winter, and then return to their traditional breeding grounds in the spring. On the other hand, some tropical birds like Baltimore Orioles began to migrate north in the spring to find better breeding grounds. A few of the many Baltimore Orioles we see in Costa Rica might have spent the summer at Valle Crucis Park, and they have returned home to the tropics for the winter.
How these birds migrate is still being studied, and we don’t have a complete grasp of how exactly birds can make these incredible journeys. We do know that birds have an instinctive sense to migrate. Most first year birds don’t follow their parents south in the Fall. Instead, each bird migrates independently of the others, and even the large mixed flocks we see during migration are only temporary gatherings. Each bird then continues their journey that night alone. Which brings me to another amazing fact about migration—most birds make their long distance flights at night. This might be to avoid predators, or they may be following the stars, or they may need to use the daylight to find the food to power the next stage of their journey. It’s probably all of these reasons and more!
To make bird migration even more fascinating, we have learned by attaching GPS trackers to migratory birds that these migrants don’t just go to the tropics and wander about. Each bird goes to the exact same spot each Winter, and returns to the same place they left in the spring. A Broad-winged Hawk will fly for 3,000 miles to reach South America, and then spend the whole winter in a three-mile territory. Researchers placed a tracker on a Prothonotary Warbler in South Carolina years ago. It flew 4,000 miles to a Mangrove Swamp in Columbia for the winter, and was then recaptured 15 feet from where it was first tagged the following spring!
Everything in nature is connected – even places thousands of miles apart. There is a good chance that we have seen the same bird in North Carolina and Costa Rica. This is why it is so important to have protected natural areas like Valle Crucis Park in the High Country, and also all over the world – if the birds that breed here at the Park in the spring and summer migrate south only to find their winter territory has been destroyed, the odds of those birds making back to Valle Crucis next Spring are very low.