During the last days, the streets of Barcelona have been filled with yellow bird droppings and with a more liquid texture than usual. The bowel movements have gone from white to yellow in the same way that we have changed the seasons.
The droppings are causing discomfort to the people of Barcelona who find these droppings on their balconies, cars and sidewalks. On Twitter there are many users who denounce the excess of defecations in their neighborhoods. The most repeated question in the conversations in this network is if the birds have some kind of intestinal problems.
According to ornithologist Xavier Riera, from the Institut Català d'Ornitologia (ICO), the change in color and texture of the droppings is due to the feeding of the birds that are ingesting the fruits produced by the banana trees. The pigment in the bud of the tree is very strong and this causes the usual color and texture of the birds that feed on it to change.
This problem is seasonal, it occurs every spring, when the banana tree begins to flower and the birds begin to feed on the fruit and pollen they generate. As the ornithologist explains, a very similar event occurs in autumn when certain species of birds feed on blackberries and their feces turn a very dark violet color and are also very staining.
Experts say they don't know what type of bird is to blame, as it could be more than one species. According to Riera's hypothesis, they are turtle doves (Streptopelia decaocto) and wood pigeons (Columba palumbus) that historically lived in the countryside but increasingly move within towns and cities. The ornithologist's theory is based on the size of the feces. Likewise, he rules out that it is domestic pigeons because they usually feed on the remains that are on the floor of the city.
As Riera affirms, escaping from the feces will not be possible. If what is intended is that the excrement does not stain the vehicles, what should be done is to park them as far as possible from the banana trees, although this species is the most abundant in the city of Barcelona.
"The only thing that the people of Barcelona can do, if their vehicles are very full of feces, is to go to a car wash because the feces may have a certain acid component that could still damage the paint. Although this is unlikely to happen," says the ICO specialist.