When it comes to birds, you’re probably familiar with many of the different kinds you might see on a day-to-day basis. There are a ton of different bird species, many of which look different from one another, but some may even look similar to one another.
Despite all the different kinds of birds that we think we know today, a new study carried out by the American Meuseum of Natural History suggests that perhaps there at least twice as many species of birds in existence today than we actually know about.
The details behind this bold hypothesis appear in the journal PLOS ONE, suggesting that there is a lot more biodiversity between bird species than previously thought because some birds that are interbred or just look alike may have went unchecked.
"We are proposing a major change to how we count diversity," said Joel Cracraft, an author of the study and a curator in the American Museum of Natural History's Department of Ornithology. "This new number says that we haven't been counting and conserving species in the ways we want."
Currently, anywhere from 9,000-10,000 different species of birds are known to exist, but these are determined by the biological species concept, an outdated means of determining different species that could really do with a 21st century re-haul.
"It's really an outdated point of view, and it's a concept that is hardly used in taxonomy outside of birds," said lead author George Barrowclough, an associate curator in the Museum's Department of Ornithology.
As a part of this study, the researchers sampled approximately 200 birds via morphology, a way of characterizing birds by their physical appearance. While using this method, as many as two different species were discovered for each of the 200 that were sampled, yielding close to double the bird species in just a small sample.
As you can imagine, this discovery has lead scientists to think that similar statistics will probably show up in greater samples, such as the 9,000-10,000 known species figure mentioned earlier. They estimate that there may be as many as 20,000 species of birds on the planet today.
Modern DNA analyses could provide more insight, as using this technique has helped to uncover new species in the past, despite how similarly some birds looked to one another. The trick is figuring out which birds to test and getting large enough samples.