The most common species in Spain is called Larus (argentatus, Michaelis, cachinans).
These birds are typical on the coast and have been slowly colonizing the interior of the peninsula, following the course of rivers.
Their traditional diet is fish, but they gradually changed their diet down to feed on garbage in landfills, and other birds like pigeons, which are abundant in our cities, becoming predators.
Their natural habitats are the crags and cliffs but landfills are good locations. A more recent phenomenon is nesting in certain buildings.
They can be easily found now in our coastal cities and inland cities, they are birds in full expansion now.
Gulls share many of the pigeons animal health problems, but being less abundant now represent no problem.
But they are for their aggressiveness. Even against humans, if they are young, threatened or hungry.
Their growing presence in the urban environment has become a threat in some cases.
Some curiosities of seagulls
It is known that gulls can drink sea water through a gland that secretes salt through tears from their metabolism.