Darwin’s Finches Are Nearing Extinction
Photo by Charles J. Sharp Last December, a study by a research team at the University of Utah concluded that one of the most common species of Darwin’s finch, the medium ground finch (Geospitza fortis), will be driven to extinction in as little as several decades by parasitic flies (Philornis downsi) first brought on the Galapagos Islands by humans in the 1960s.
The team, led by senior researcher and biologist Dale Clayton, used five years of field data to design a mathematical model to predict when the medium ground finch will go extinct within fifty years “given bad reproductive years in which extreme weather cuts off their food supply,” within eighty years given neutral years, and about 100 years given luck in reproductive years.
The eggs of the flies hatch into maggots that feed on the finches, killing baby birds. As Clayton told Smithsonian Magazine, “This is like a really bad horror flick. The babies can’t withstand even one night with these parasites.”
Researchers believe that extinction could be slowed or stopped if nest infestations were reduced by 40 percent, something that could be accomplished if we helped by introducing sterile male flies into the population or by putting out pesticide-treated cotton balls for the finches to collect for use when building their nests.
Darwin’s observations of the types of beaks of varying finch species on the island, the product of rapid evolution in response to their food type, informed his work on evolution by natural selection.
This is not the only culturally symbolic organism that is endangered: Panama’s golden frog (a “symbol of hope”) has been extinct from its natural habitat since 2007; more than 90 percent of Madagascar’s lemurs are endangered; and a survey by the World Wildlife Fund estimates that wildlife population has decreased by 52 percent between 1970 and 2010 (a recent Science study shows that biodiversity loss caused by humans could be the sixth mass extinction).
Not only is the preservation of biodiversity and nature on Earth humanistic, but the sustainability of our ecosystems is deeply important to our own self-preservation (and economic output). As we celebrate Darwin’s deeply useful learnings, let’s not forget to use this knowledge to keep our Earth in balance.