A Work of Hope - Feral: Rewilding the Land, the Sea, and Human Life - page 142

Some people appear to be giving serious consideration to the idea of
restoring another missing member of the Siberian ecosystem. Whatever
the drawbacks may be, the notion (which might or might not be fanci-
ful 61 ) of resurrecting the woolly mammoth by extracting genetic material
from frozen corpses and injecting it into the eggs of Asian elephants pos-
sesses the virtue of firing the imagination on all cylinders. But it seems
odd that, while there has been so much attention and money given to this
project, the idea of simply reintroducing the Asian elephant to parts of
Europe and Asia, from which it or its sibling species (the straight-tusked
elephant) has been extirpated, has not yet taken root; or even, as far as
I can discover, been discussed. The elephant in the forest - the huge and
obvious fact that almost everyone has overlooked - is the most prodi-
gious instance of Shifting Baseline Syndrome I have chanced upon so far.
Who knows what else we might all have missed?
The North American debate raises another important question, which
is relevant everywhere: is a healthy and desirable ecosystem necessarily
composed of native species? Certain exotic animals and plants destroy
ecological diversity of all kinds in the places they infest. Without natural
predators or parasites or diseases, attacking native species which have
evolved no defences against them, they can quickly overwhelm an eco-
system, sometimes to the point at which (as I have seen in small streams
in England infested by American signal crayfish) the last robust ecol-
ogical process still taking place consists of big ones eating little ones.
In some places the progress of these invasive species looks like the plot
of a Gothic novel. The walking catfish, for example, native to south-east
Asia, has escaped from fish farms and ornamental ponds in China and
the United States, and now crawls overland at night, colonizing water
that no other fish can reach. 62 It eats almost anything that moves. It slips
into fish farms and quietly works through the stock. It burrows into the
mud when times are hard and lies without food for months, before
exploding back into the ecosystem when conditions improve.
The cane toad, once confined to Central and South America, has
been widely introduced in the tropics to control crop pests. Unfortu-
nately it also controls many species which are not considered pests. It
than grass, preventing the permafrost from thawing and releasing the methane and
carbon dioxide it contains. It is not clear at this stage which effect will dominate.