The proliferation of coqui frogs in Hawaii has had a significant, and surprising, impact on non-­native birds — not that indigenous birds have bothered to notice.

A new study by researchers at Utah State University, conducted at 15 sites on Hawaii island in 2014, found that the increased presence of the racket-producing little frogs actually boosted the number of non-native birds in the affected areas while registering no adverse affect on native birds.

Puerto Rican coqui frogs first arrived in Hawaii in the 1980s and now number as many as 91,000 per hectare in some locations.

It was long assumed that the introduction of the frogs would negatively affect local bird populations by increasing competition for available food.

The Utah State researchers found quite the opposite.

The study found that native birds showed no response to the presence of coqui frogs, likely because the frogs forage in leaf litter while native insect-eating birds forage mostly in the canopy and understory of forests.

Even more unexpected, non-native bird numbers actually increased where coqui density was the highest.

The scientists think non-native birds may be feeding on adult or juvenile frogs and that the frogs’ excrement and carcasses might increase fly populations, which increases the food supply for insect-eating birds.

“I was very surprised with the results for birds,” researcher Karen Beard said in a news release. “It had been hypothesized before our study that coquis would compete with birds, particularly natives, because we know that coquis reduce insects where they invade. In retrospect, I guess it’s not too surprising that predation is a more important interaction than competition … but it was definitely not what we went in to test.

“The response we see for common mynas and red-billed leiothrix is pretty convincing,” she said. “We’re pretty sure that some of this increase is due to these species eating live or dead coquis, and we’re suggesting that some non-native birds are likely consuming coquis and this novel resource appears to be increasing their populations.”

The findings are published in the latest edition of the journal The Condor: Ornithological Applications.