More Than Just a Tune
Take a walk outside and listen for a moment – odds are you’ll hear a variety of birdsongs functioning as nature’s own soundtrack. While birdsongs are known and enjoyed by many, a lesser known fact is that these songs actually define separate species, or populations of animals that don’t mate with one another. Recently, scientist Benjamin Freeman made a fascinating discovery. With the help of birdsong, he determined that a population of Rusty-breasted Antpittas, previously thought to be one species, should actually be classified as two separate species.
The Rusty-breasted Antpitta. Image source: Tony Castro
How it Happened
Rusty-breasted Antpittas, which are small birds native to Central and South America, are affectionately referred to as “eggs on legs” due to their small size and round shape. The Antpittas which Freeman investigated in his 2018 study live in the Andes, and travel by hopping and running. Because the birds are unable to fly, the mountains and valleys within the Andes form geographical barriers between groups of Antpittas.
The Andes Mountains. Image source: Lucia Barreiros da Silva
Over the past few million years, the northern and southern groups of Antpittas evolved differences in their songs and genetics due to this separation. These differences, in fact, are so great that Freeman believes the two groups to be separate species – that is, they would not mate if they were to encounter one another. For an insider view of how Freeman believes the two populations have become separate species, check out the video below.
https://www.youtube.com/watch?v=RQU3cPAofeE&feature=youtu.be
What is Speciation?
The process of a population separating into multiple species, as seen in the Rusty-breasted Antpitta, is referred to by scientists as speciation. A common cause of speciation is when populations are separated by geography – in the Antpitta’s case, the barriers were formed by the mountains and valleys of the Andes. And as climate change causes temperatures to rise, this effect can become even more extreme: species move to higher elevations in order to reach their preferred temperature ranges, causing populations to separate even further and develop more differences. The podcast below paints a more detailed picture of speciation, and how the presence of different species can make the world we live in a more exciting and colorful place.
A Final Note
The story of the Rusty-breasted Antpitta is just one example of the processes that are occurring around us all the time. From birds, to bugs, to beluga whales, each species on Earth has unique traits that were formed by years of speciation. So the next time you step outside and find yourself listening to birdsong, take a minute to appreciate it – chances are, it’s more meaningful than you might have thought!
By Olivia Campbell, Morgan Kaye, Kevin Keum, & Sarah Speckmaier
