When it comes to the decrease in biodiversity and living species at risk of extinction, there is a category that always tends to underestimate or even consider so harmful that even if it disappeared it would not be a big problem.
We are talking about the parasites, present in most of all the living species and therefore risk disappearing with them. This is the case of the coco, the heaviest parrot in the world: at risk of extinction for more than a century now, the decline of its population is also leading to the disappearance of its parasites, and we still do not know the consequences of this loss. A study published on Current Biology.
A dive into the feces. The fact that the cacapo has been recognized as an extinction as early as 1890, and that in those years the first protection and conservation operations began, has allowed to have a huge amount of data on the cacapo available, and in particular on its feces, which have been collected and studied for more than a century.
Not only that: this giant parrot, endemic of New Zealand, has also left a considerable inheritance in the form of coprolitis (ie fossilized poop), with “specimens” that date back to 1,500 years ago.
On the hunt for parasites. Being able to analyze the feces of the cacapo in the last 1,500 years, the team that has conducted the study has also identified the parasites that coexist with this bird. And he discovered that more than half of the taxa Parasites present before the nineties (of the last century) disappeared from the feces of the cacapos.
Not only that: out of 16 taxa Several that populated its intestines, nine were extinct even before the nineties, and four others disappeared. The choice of the nineties as a turning point is not accidental: it is the moment when the few specimens of cacapo remained were put under total control to prevent their extinction. Here: it served them, less to the parasites that populated them.
The advantages of longtime coexistence. Could you at this point ask yourself: isn’t it better this way? After all, parasites are harmful by definition for their guest. Why should it be sorry if they extinguish?
First of all because, if they are extinguishing, the reason is in the decline of the cocoa population: the less guests there are, the more difficult it is to thrive. It is even possible that all the cacapo parasites end up extinguishing before their guest: it would be an important loss for biodiversity.
Finally, there is the fact that parasites are not only harmful: the question is still studied and debated, but there are those who claim that they help the development of the immune system, and that they also act as a shield against other new parasites that could be more harmful to the guest.
In short: if there are parasites with which cocoing coexist for millennia, it is better that they remain that they are now adapted to coexistence, because the “new arrivals” could prove even more dangerous.
