* The author is part of the community of readers of La Vanguardia
In the Photos of the Readers of La Vanguardia we can appreciate the perfect formation in flight of the crane, of great geometric beauty drawn in the sky. In this case, the photograph has been captured in Altet, in the Urgell region.
I couldn't take more photos due to the presence of a car, which caught my attention at that moment. The sun was practically on their back but I would say they were going north, northwest at most.
The cranes are huge and unmistakable. They arrive in the Iberian Peninsula around the month of October, where they remain until March. It is a wintering species, especially in the pastures of Extremadura, both Castiles and Andalusia.
Part of the European crane population does not leave the migratory passage areas during the winter months, such as the Gallocanta Lagoon, and remains there during the winter, feeding in the cereal fields and using the lagoon as a roost.
A flock is a group of birds, generally of the same species but not necessarily, that act in a homogeneous manner while flying or feeding. This term is similar to the concept of a herd among mammals.
The formation of flocks has a clear defensive function. They can also meet to start migration, as this seems to be the case in this image captured in the sky of Urgell.
In order to be able to aggregate and take a joint course without colliding with each other, there are several theories. The conclusion is that the movement of birds in flocks follows a physical model similar to magnetism but modified. Each bird has its own movement and changes in speed of a single bird affect everyone in the group.
