The team ran simulations based around three broad future scenarios: "good" years likely to come, where conditions such as weather and food supply were conducive to successful breeding; "bad" years ahead; and neutral years, where both bad and good conditions were equally likely.
Two of the three model runs -- "bad" and neutral -- predicted the medium ground finch's extinction. Only the "good" model showed the species able to survive.
The "bad" model predicted extinction in anywhere from 43 to 57 years, while the "neutral" model had the bird disappearing in 65 to 95 years.
Video Shows Birds Having An Argument
Worse still, the problem may not just apply to the medium ground finch. Study lead author Dale Clayton, a University of Utah biology professor, pointed out that the bird's other Galapagos cousins could be at risk as well.
If a species of Darwin's finch as common as the medium ground finch can face extinction because of the nest fly, "then the less common species, which have the same fly problem, are likely at risk as well," Clayton said in a release.