MAUI — For being such a tiny frog the coqui gets big attention around here, with some describing it as an ecological disaster and others dismissing it as a harmless but noisy nuisance.

The truth, it appears, is somewhere in between, according to a scientific study to be published next month in the scientific journal Diversity and Distribution.

"They're much more than a noise nuisance but there are worse things out there," said William C. Pitt, researcher with the National Wildlife Research Center Hilo Field Station. Pitt and Utah State University scientist Karen H. Beard wrote "Potential consequences of the coqui frog invasion in Hawai'i."

The 2-inch frog, a relative newcomer from Puerto Rico with a loud call, has already affected the state's nursery and tourism industries. However, not much is known about the ecological consequences of their presence.

"We wanted to take an unbiased look at all the evidence about its impacts," Pitt said.

In looking at the problem, the authors examined data from both Puerto Rico and Hawai'i.

One of the fears most expressed about the coqui here is that its spread might lead to an acceleration of the loss of Hawai'i's endangered forest birds. The theory is that the growing population would compete with the birds for insect prey.

But Pitt and Beard found that, at least for now, there is little overlap between the low-elevation habitats occupied by the frogs and the higher-elevation range of the birds.

Although coquis may make bird "reinvasion" into lowland ecosystems more difficult, they might also serve as an additional food source for some endemic birds, the study said.

Another big fear has been the possibility the coqui would reduce the abundance of Hawai'i's endemic insects, spiders and other bugs. However, data suggest that coquis are consuming mostly non-native bugs. Their diet apparently does not include mosquitoes and termites, though.

Some have also predicted the coquis would serve as a food source to help bolster populations of rats and mongooses, which are predators of endemic birds. But preliminary data suggest that coquis will not be a food source that will result in a rise in rat or mongoose populations.

It does appear the coqui would be an excellent food source for young brown tree snakes, if the snake that has decimated birds on Guam were to become established in Hawai'i, Pitt said, noting that would cause much more damage to Hawai'i's environment than the coqui.

Commercial shipments of plants for nurseries and other businesses are believed responsible for introducing to the Islands the coqui and an assortment of other pests, ranging from stinging caterpillars to fire ants.

According to the study, it is unlikely that coquis will ever be eradicated from the Big Island and Maui, where there are now hundreds of populations.

Quick and severe responses to new introductions on the other islands may be the only effective means of containing the spread of the frogs, the study said.

Reach Timothy Hurley at thurley@honoluluadvertiser.com.