Islands Fighting Back Against Rats

Animal News

Cleaning up the messes we make out of Mother Nature is a delicate business, lest we make things worse with the solution. Ships stop at many islands around the world, inadvertently introducing rats that ate native species, particularly their eggs. South Georgia Island in the South Atlantic is one such habitat. Once the premiere breeding ground of seabirds, South Georgia became overrun by rats, and the number of birds there dropped like a stone, to 1% of the former population. Many schemes have been tried (remember operation cat drop?), but conservationists may be making headway with new techniques.

The projects try their best not to hurt the species they're supposed to protect.

For one, the rat poison, brodifacoum, is not water soluble, so it can't leach into the groundwater or poison waterways.

Some seabird scavengers could eat stricken rats and become ill, though the rat carcasses are hard to find: The poison makes the rats photophobic, or shy of light, so the rodents usually retreat to their burrows before dying.

It's possible that a few duck or other birds may ingest the poisonous pellets, but since rats eat thousands and possibly millions of chicks a year overall, poison is still the better strategy, experts say.

South Georgia Island is not the only island undergoing rat eradication projects.
Read about several of them at NatGeo Newsink.