If there’s anything that flamingos are known for, it is for the pink color that their feathers are composed of. And since not all of them retain their color of pink, this change in color has long been attributed by scientists due to the sun’s rays as well as also being unintentionally stained by organic materials.

However, according to research conducted by scientists at the Doñana Biological Research Station in Spain that studied these greater flamingos in detail, it was realized that the seasonal appearance of this pink color or makeup was due to the fact that they wanted to impress their mates. The color of pink was discovered to stem from this activity of applying oil that is secreted by a gland near their tails all over their feathers by using their beaks.

After the mating season was over, these adult flamingos that had the pink makeup had apparently lost their color when the chicks were just hatching, and this led to the conclusion that there was something else was the reason for this color loss.

And so, in order to find out what was occurring, scientists studied the seasonal variation of color amongst flamingos in three wetlands in Spain, where aspects of feather maintenance, courtship activities and breeding patterns were also observed closely. When it came to the variation of color amongst these flamingos, the scientists assigned a color value on a scale of one to three, from pale to vibrant pink.

In their findings, it was revealed that the average color value of these birds was at a score of 1.7 at the peak of the mating season (in February) whereas it was at its lowest (almost 1.0) when they were tending to the hatchlings during the months of May to September.

And while it was found that the deeper the pink, the more attractive the flamingo was thought to be, this has led to a reason for these scientists to conduct research as to whether other species of birds also apply cosmetics to do the same.