Human-caused climate change appears to have driven the Great Barrier Reef’s only endemic mammal species into the history books, with the Bramble Cay melomys, a small rodent that lives on a tiny island in the eastern Torres Strait, being completely wiped-out from its only known location.
Marsupials are of course mammals. Rodents are not marsupials. And Australia is rather famous for not having rodents but for having marsupials.
So, first order thought would be that this was an introduced species in the first place.
Second order thought is that this might not be quite true up around the Torres Strait and Cape York. Because that’s where those two biospheres, the one with rodents in and the one with marsupials in, sorta meet. Umm, maybe: as you can tell I’m not claiming expertise here.
Third thought is that any species which lives only on one 5 hectare (or whatever) island isn’t going to have a long run as a species. You only need a bit of erosion and it’s gone. Or a decent tsunami or summat.
Not quite the importance to it that some are claiming then I would have thought.
It is also the first recorded extinction of a mammal anywhere in the world thought to be primarily due to human-caused climate change.
Unconvinced to put it mildly.
Aha! Via twatter, I am enlightened:
The small population size means genetic drift, disease and introduced species all pose a threat to the species.
Habitat loss via erosion of the cay is the single most important threat, particularly given that sea levels are predicted to rise thanks to climate change. Bramble Cay is by no means stable. Between 1958 and 1987, the cay decreased in size; but in 2011 it had returned to a size comparable to 1958.
While the size of the cay varies, the vegetation on it is shrinking, and this might be the main cause of the melomys’ decline.
Climate change and rising sea levels not so much then perhaps?