Migration paths for migratory birds are necessary for survival. For quite a long time — centuries, science has marveled at the pathways and how they’re so closely adhered to. The community questions how migratory birds locate their migration routes so easily, and studies have been undertaken to figure that out.
More than 70 years ago, biologist A.C. Perdeck took 14 thousand starlings off their usual path by plane, releasing them in Switzerland and Spain from their origin in the Netherlands. The birds were outfitted with leg rings for ID purposes, each with a unique code. It was discovered was that older starlings adjusted their pathway to reach the normal areas they were accustomed to. Younger starlings, however, moved in a south-westerly direction but reached incorrect locations.
The younger starlings were thought to have befriended new flocks, as they are highly social and get along with others. Some hypothesize that the younger starlings merely assumed routes with their new friends. But new, more recent findings suggest that starlings do not learn their migratory pathways, they inherit them.
Guided By Instinct
By reviewing older datasets, the new study now shows conclusively that the starlings did not follow the pathways of any newfound friends but rather traveled independently and based on what they instinctively knew was correct. It is known that starlings migrate at night. With this new information merged with that of the 70-year-old Perdeck study, changes have been made to previous beliefs. Starlings (and other birds) have an inherited, directionally-based inclination for migration. So, why did the younger starlings, although headed in the right direction, miss the mark when the older ones nailed it so efficiently?
It is assumed by way of the more recent study that the starlings did not so much miss the mark by means of aligning with other migratory birds, but that it was because it was their first migration. This study explores genetic and ecological differences that lead to a need to migrate and the direction of travel. The mass of data, all recorded on paper, has supplied a large amount of necessary and documented information to assist in this and other future studies.
The importance of this study has a bleed-over effect for other things. For example, if it was determined that the young starlings were influenced by other species in migration pattern, then it indicates that birds could be influenced to adapt to different environments and habitats. This could have had a far-reaching impact on helping birds adapt. Now, we come to a better understanding that birds have built-in motivation based on season and direction that are not learned. They are naturally inherited.
The current debate continues, but science is getting smarter about birds all the time. You can explore this particular study here, which was published July 3, 2024.