Bird Tracking Technology Part 1

Autumn is nearly finished and many birds that migrate have flown south for the winter. Have you ever looked up at a V-shaped formation of flying Canada geese and wondered, “Where exactly do they go for the winter?”

Birds of all shapes and sizes, from songbirds to waterfowl to birds of prey, such as hawks and falcons, migrate, but not all ‘fly south for the winter.’ Some birds migrate locally to where food sources are and stay north or in the United States all winter long. Other birds fly between their breeding grounds of the Canadian boreal forests to their wintering grounds in the jungles of Central and South America. So how do we know where they all go? Thank the constant innovations in technology to give us the answers.

This series will delve into the details of different types of tracking devices, from unpowered tiny polymer bird leg bands to solar battery powered transmitters bird backpacks. These devices shed light on the science of bird behavior and in the end where exactly different birds really do go for the winter.

A Little History - Silver Wire as Identifiers and Banding Birds

Some of you may have heard of the most notable cataloguer of birds here in the United States: John James Audubon. Audubon was born in what is today known as Haiti, which was known as Hispaniola during the 1700’s and under the control of France then led by Napoleon. With war raging in Europe at the time, Audubon’s father wanted to save his son from being drafted into Napoleon’s Army, and so he shipped John off to America where he settled in Mill Grove, Pennsylvania. In the bucolic landscape of his new home Audubon discovered various birds he had not seen in his native Hispaniola. He noticed species of birds nesting on his farm during the spring and seeing the same looking birds nesting again in different trees on his farm the following year. Audubon wondered if they were the same birds that returned each year and concocted an idea of using silver wire tied around a nesting bird’s legs to see if it really was the same bird. To his delight and luck, he noticed the following spring that the same birds returned to his farmstead with the silver wire and tags still attached. This was the first time “banding” of birds was initiated in the young United States. Audubon’s passion for birds was fueled by this experiment, and led him to document this young nation’s birds through his famous paintings, which are still renowned today around the world.

Banding birds was nothing new though. Four hundred years before Audubon and on the other side of the world, in western China, Mongolia, and the Middle East, the use of falcons and Golden Eagles were typically employed for hunting. During the 1200’s, these Asian falconers affixed at silver tablet to the feet of the bird, which had the owner’s name imprinted upon it, to identify the bird as owned by another. But even before that, pigeons were ‘banded’ with tiny pieces of parchment with inscribed messages by the Romans to send messages to far away generals throughout the Roman Empire. Although these different forms of banding did not identify exactly where birds ‘migrated’ to, it did establish a way to identify the bird when it was found.

Check out next week’s post to learn about modern bird banding technology.