It turns out all those eco-tourists who flock to the Galapagos Islands are doing real damage. Reuters:

LONDON (Reuters) — The unique wildlife of the Galapagos Islands is under threat from disease-carrying mosquitoes arriving on board growing numbers of aircraft and tourist boats, researchers said on Wednesday.
Experts fear the spread of the southern house mosquito, or Culex quinquefasciatus, could have the same devastating effect in the Galapagos as in Hawaii during the late 19th century, when disease wiped out many indigenous birds.
The mosquito was first spotted in the Galapagos in the mid-1980s, but its presence then was considered a one-off.
Now research by British and Ecuadorean scientists has found the insects are, in fact, transported regularly by plane and are island-hopping on boats, spreading throughout the archipelago.
Genetic tests also confirm they are able to survive and breed once they arrive at their new home.
“More ships and more aircraft are coming to the Galapagos every year and the risk of something being introduced is growing all the time,” said Leeds University researcher Simon Goodman.
“That we haven’t already seen serious disease impacts in Galapagos is probably just a matter of luck.” The southern house mosquito is a carrier of diseases including avian malaria, avian pox and West Nile fever.
It was brought to Hawaii in water barrels on whaling ships, leading to diseases that are blamed for wiping out many bird species. Only 19 out of 42 species and subspecies of honeycreeper now remain in Hawaii.
Goodman and colleagues, who published their findings in the Proceedings of the Royal Society, fear everything is in place for a similar wipe-out in the Galapagos, given the rapid growth in transport links with the mainland.