A fascinating citizen science project has successfully mapped the distribution of dialects in yellowhammers (Emberiza citrinella) in both New Zealand and the UK.
Yellowhammers, like us, have regional dialects, with differences in their song depending on the region that they live. A familiar farmland bird in the UK, the species was introduced to New Zealand over 100 years ago, and this has provided researchers with a unique opportunity to investigate two completely isolated populations.
The Yellowhammer Dialects project used citizen science volunteers to record yellowhammer song in the field. This allowed the project to access lots of data from across a very large area, which was then compared with historic recordings from archives. All this information was then used to accurately map the composition and distribution of different dialects in the two countries.
Researchers found an interesting difference in dialect between the populations of yellowhammers, with New Zealand yellowhammers sing nearly twice as many different dialects than yellowhammers in the UK.
They explain this result by suggesting that New Zealand yellowhammers have retained song structures which were originally from the UK, but have subsequently been lost in the mother country, perhaps due to the widespread decline in yellowhammers in the UK.
The yellowhammer dialect system may be the avian equivalent of a phenomenon already noted in human languages, in which ancient words or structures are retained in expatriate communities.
A fascinating finding, and one which will hopefully be complemented by further results in the near future; after the success of this project, the researchers have decided to host sister projects in both Switzerland and Poland.
The full research paper can be found here.