The United Kingdom’s Royal Society for the Protection of Birds (RSPB) has recorded the first known instance of invasive mice preying on the adult albatrosses, according to a press release.
Past research has documented Gough Island’s invasive mice preying on albatross chicks. But this is is the first times on record that mice have been seen gnawing on living adults on Gough Island. The RSPB now fears for the fate of the rare birds that breed there.
Gough is a remote South Atlantic island and is one of the most important seabird breeding colonies on Earth, hosting millions of breeding birds from two dozen species, including exceedingly rare seabirds like the giant Tristan albatross.
Only 2,000 pairs of these enormous birds (they have a 3 metre wingspan) remain, nearly all of which breed on Gough. This species relies on a breeding strategy in which parents raise single eggs every other year. This strategy is called K-selection: Species that compete for limited resources, like albatrosses, spend more time raising fewer offspring that will hopefully have a higher chance of making it to adulthood.
But the remote island has felt the impact of humans over the past few hundred years, including visits from explorers and seal-hunting vessels. And like always, human visitors inadvertently bring non-human stowaways. In Gough Island’s case, the troublesome invader is the common house mouse, first introduced over 100 years ago.
Without other sources of food, the mice began to prey on defenceless albatross chicks, who are raised in nests on the ground and don’t have a means to escape the mice’s attacks. This feeding strategy was successful, and mice are now a major threat to the survival of this impressive species.
New video evidence has revealed attacks on adults, as well. The video, taken earlier this year by researchers on the island and released yesterday, shows mice attacking a member of a different South Atlantic albatross species, the yellow-nosed albatross. This has raised further concern for the fate of the seabirds on the island.
“We have known for more than a decade that the mice on Gough Island attack and kill seabird chicks. While this is already of great concern, attacks on adults, which can produce dozens of chicks in their lifetime, could be devastating for the populations’ chances of survival,” Chris Jones, senior Gough field assistant, said in the press statement from the RSPB.
These attacks may only accelerate the Tristan albatross’s impending extinction. The RSPB is now working to eradicate mice from the island, despite strange pushback from some animal rights activists.
Invasive species are one of the main causes of extinction around the world. Humans merely showing up to a pristine habitat can inadvertently release a barrage of opportunistic species like mice, rats, cats, livestock, and plants, which then out-compete the native species that have never had to deal with this sort of competition before. It’s like humans being introduced to a virus they aren’t inoculated against—with no defences, we die en masse.
One can only hope that attempts to cull mice on the island will be successful.