16:54 23 May 2016
A pair of scientific studies, which both examined the DNA of birds that either gained or loss their redness, have identified an enzyme that lets birds convert yellow pigments from the food they eat into red ones, which are then deposited in their feathers of beaks.
Both studies were published in the journal Current Biology.
Dr Miguel Carneiro from the Universidade do Porto, Portugal, said: "Birds cannot synthesise these red pigments endogenously. They have to obtain them from their diet,"
"It was known for a long time that an enzymatic conversion is needed to produce the red pigments. So many groups of geneticists and physiologists, for many decades, have tried to identify the enzyme that does this conversion."
Dr Carneiro and his team began their search with the “red factor” canary.
He said: "Some people consider it to be the first genetically engineered species,"
"By a number of crosses, throughout many generations, they fixed the ability to convert yellow pigments into red pigments, in some breeds of canary.
"What we did… is try to look at sections of the genome in red factor breeds that actually belong to the red siskin - and that's how we got to the gene."