DWhichever way you look at it, the kakapo is an incongruity of nature. First of all, its measurements. Its size – 60 centimetres long as an adult – places it among the largest parrots in the world. Above all, its weight – up to 4 kilograms – crushes the competition. It must be said that it is the only one in this large family that does not fly. On the other hand, with its super-powerful legs, the New Zealand rider is capable of covering several kilometres in a day. Or more precisely in a night, since during the day, the “owl parrot”, the first name given to it by European explorers, sleeps.
Its exceptional nature does not stop there. Its life expectancy is close to 90 years and some individuals have reached 120 years. A record attributed to a particularly slow basic metabolism. Its head has a facial disc, again in the style of an owl, and its light blue beak is surrounded by whiskers, real detectors that help it to orient itself, head down, during its long excursions.
Let’s move on to its name, which, even if it may not be unrelated to its success, has nothing to do with any parental injunction at the time of the child’s first words. It simply means “night parrot” in the Maori language, the indigenous people of New Zealand. On the other hand, it is impossible to avoid the extraordinary ritual – the lek – which surrounds its reproduction. The males build arenas, attract the females by means of deep and percussive cries and confront each other, every night. The winner then performs a final parade which, if all goes well, results for him in one or more matings. The loser will try his luck another night.
All this might have seemed sufficient. But an international team of biologists has decided otherwise. In an article published Tuesday, September 10 in the journal PLOS Biologyshe has just described and explained one last mystery surrounding the bird: its color. The approximately 250 existing animals in fact offer two distinct plumages. Green for half of them, olive for the others. To those who would object that olives are green, the researchers specify that if the two shades do not differ spectacularly to our eyes, they actually present a very distinct spectrum of light reflection.
“A balanced selection”
This nuance does not come from any disparity in the dye present in the feathers. The analysis of 168 individuals made it possible to precisely locate the region of the genome incriminated. And to conclude that the mutations caused a change not chemical but physical in the feathers. A difference in structure quite clear under the electron microscope, but especially clearly visible by certain predators coming from the sky.
You have 49.89% of this article left to read. The rest is reserved for subscribers.
