According to the principle behind Chesterton's Fence, it isn't safe to allow any species to go extinct before we can understand its role in the ecosystem.
Knowing that, we could selectively breed and engineer new species to fill the critical niches of species as they go extinct, so that the long-term viability of our own species and our allied species are never threatened.
The trick is understanding the point of certain threatened species as they are on the brink of extinction. It's hard to know if that species ever had an essential function if it isn't doing it any more.
Since it's been gone so long, Chesterton's Fence must also be applied to the question of understanding what the passenger pigeon's new role would be in today's ecosystem.
Knowing that, we could selectively breed and engineer new species to fill the critical niches of species as they go extinct, so that the long-term viability of our own species and our allied species are never threatened.
The trick is understanding the point of certain threatened species as they are on the brink of extinction. It's hard to know if that species ever had an essential function if it isn't doing it any more.