European Starlings were intentionally released by the American Acclimatization Society in 1890 because they wanted America to have all the birds that Shakespeare ever mentioned among other European birds. Every European Starling is a descent of the original 100 birds set loose in New York’s Central Park. Genetically, those from Virginia are practically indistinguishable from starlings in California. Today, more than 200 million European Starlings range from Alaska to Mexico, and many people consider them pests.
Starlings are related to the mynah bird and thus are great vocal mimics. Many can learn the calls of up to twenty different species. Birds whose songs starlings often copy include the American Robin, meadowlarks, Eastern Wood-Pewee, Killdeer, Northern Bobwhite, Wood Thrush, Red-tailed Hawk, Northern Flicker, and many others.
Starlings often participate in what is called a murmuration, where a huge flock shape-shifts in the sky as if it were one swirling mass. This is often caused by the presence of a predator and the flock’s movement is based on evasive maneuvers. There is safety in numbers, so starlings do not scatter, they move as an intelligent cloud, maneuvering from the hungry raptor, thousands of birds changing direction almost simultaneously. Scientists have been stumped as to how a bird, tens or hundreds of birds away from those nearest danger, sense the shift and move in unison?
Giorgio Parisi, a theoretical physicist with the University of Rome, published a paper about starling murmurations in the Proceedings of the National Academy of Sciences in 2010.
“The change in the behavioral state of one animal affects and is affected by that of all other animals in the group, no matter how large the group is. Scale-free correlations provide each animal with an effective perception range much larger than the direct interindividual interaction range, thus enhancing global response to perturbations.”
In 2012, Dr. Parisi published additional research showing that each bird is actually reacting to the birds nearest to it, that the movement is the result of a series of short-range reactions. With the 2010 study, the team looked at velocity; this time they studied orientation. Measuring how a change in direction by one bird affects those around it, the team discovered that one bird’s movement only affects its seven closest neighbors. So one bird influences its seven closest neighbors and each of those neighbors’ movements affect their closest seven neighbors and so on and so on. This is how the flock is able to look like a twisting, changing cloud with some parts moving in one direction at one speed and other parts moving completely opposite.