They are birds that use this strategy to guarantee their survival
With the arrival of the cold the characteristics also appear flocks of starlings that brighten the Spanish skies. These great accumulations of birds, which form undulating, dynamic clouds, in harmonious movement, seem to behave as if they were a single organism. No one who has seen them can help but be fascinated. But why do they act like this? It is not something capricious, but a survival strategy.
Starlings are birds that inhabit forests, agricultural land, tree crops, parks, gardens and urban centers; that is, practically everywhere. In fact, they are present in almost the entire Iberian Peninsula.
In Spain there are two different species: the black starling (Sturnus unicolor) and the European starling (sturnus vulgaris). While the first lives on the Peninsula throughout the year, the second is wintering.
As José María de la Peña, from the Spanish Ornithological Society (SEO/BirdLife) explains, being very gregarious, both species form huge flocks during the winter when food is scarce.
In those great clouds of starlings there may be up to tens of thousands of birds flying simultaneously and perfectly synchronizedas if it were a gigantic aerial ballet.
Also, in many cases, those aggregations contain both spotted and black starlings (while the former is light-flecked, the latter is totally dark).
“In addition to making foraging less tedious, the bands serve the starlings to avoid or mislead possible predators that roam the area. And it is that it is much easier to detect any threat, since there are thousands of eyes pending any intruder,” says De la Peña.
Predators have a very difficult time getting hold of a starling in these conditions, because the formations in which they fly do not follow a constant direction, but make careful turns, change orientation, hollow out on one side or the other and regroup unexpectedly… This is how they manage to disorient the huntedr, even if it is the fast hawks, because they cannot concentrate on a specific bird.
It is a strategy very similar to the one followed by schools of fish in the sea, adds De la Peña.
These large flocks form only in winter, when the starlings do not have to care for their young and can spend more time on their own survival.
But how do they manage to hold those formations together, even moving so fast? The same ornithologist offers us the answer: One of the factors used by these birds is communication in mid-flight. And it is that the starlings fly making a lot of noise, so that they inform the rest of the members of the flock about their position. It is the way they have to avoid colliding with each other or hindering each other.
The other mechanism they use for their coordination is light and dark. “During group flight, they always tend to follow the dark silhouettes of their companions and avoid clear areas where they see light. This is what creates those quick movements and allows sudden changes in direction & rdquor ;, he adds.
However, they do not always fly in this way, because for a group of these characteristics to form, there must first be a sufficient number of starlings. It will be easier to see these flocks in the right habitats and near their nests.
In this video you can see how these flocks fly.
Regarding its state of conservation in Spain, Neither one species nor the other presents any threat situation, according to SEO, and even their populations are expanding in our country. Their ability to adapt to almost any habitat makes them especially versatile and immune to the impacts that do threaten many other species.
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