For the first time, researchers have obtained evidence of a split in the migratory patterns of a bird species – a behavior that has been hypothesized to potentially lead to the formation of new species.
The European blackcap, which typically breeds in Austria and Germany, is beginning to migrate to different locations for the winter: one group heads south to Portugal, Spain, and southern Africa, while the other group flies north to the United Kingdom and Ireland.
Scientists studying these two groups discovered that the birds that continue to “head north” during winter tend to pair up when returning to Austria and Germany. They also have more offspring compared to the group that migrates south – a factor that may enhance their evolutionary prospects amid this divergence.
The group of blackcaps flying to the United Kingdom tends to return to their breeding grounds earlier than the group heading south, allowing them to secure the best territories, according to ornithologist Stuart Bearhop from Queen’s University (Northern Ireland).
Whether the simultaneous occurrence of selective mating and the production of more eggs will create an evolutionary split between the southward and northward migrating groups remains an open question. However, the identification of this phenomenon by scientists marks an important step in understanding this potential.
T. An (according to Scientific American)
