Warming climate is quieting Kauai's colorful forest birds

In Hawaii's Kauai island, the native forest birds are in peril. Once considered a paradise for the colorful songbirds, the island has lost more than half of those native species.

What's happening on Kauai could be an early warning for the other Hawaiian islands.

Native Hawaiian songs tell stories of the islands, including one that was inspired by the last mating call of a now extinct bird, the Kauai O'o.

"We still sing it with hope in our hearts," says Sabra Kauka, a Native Hawaiian who is a revered teacher of the island's culture.

"Our seabirds, our mountain birds they are just indicators of the health of the earth," she says.

On the west side of Kauai, the Alaka'i Forest has provided a home to the islands native forest birds for millennia. It's a different picture here than the beaches and palm trees that grace most Hawaiian postcards. Trails cut through a misty bog of moss covered trees and dark green ferns. It is cool, and disturbingly quiet.

On a recent walk through the forest, Lisa Crampton strained to hear the sound of a honeycreeper way off in the distance.

She's coordinator of the Kauai Forest Bird Recovery Project and says not that long ago, maybe a few decades, there were so many birds here.

"We wouldn't be able to have a conversation ... It was a much, much noisier forest," she says. But in the last 10-15 years, "many of our species are in 70 to 90 percent declines -- that's how fast the populations are collapsing."

Loss of native habitat and the introduction of invasive species like rats, wild pigs and feral cats have contributed to the birds' decline. But, Crampton says, mosquito-borne avian diseases from the island's warming temperatures pose the biggest threat.

"These mountains that we are in have provided a cold high elevation refuge for the birds," Crampton says, "but as the planet warms that refuge is getting shrunk down."

Shrinking now and could be completely gone within a decade, Crampton says. Conservation efforts including rat control, captive breeding and habitat restoration are underway.

Of the eight forest bird species on the island, three are listed as endangered. Among them is the puaiohi. The small gray and brown bird with pink feet now numbers less than 500. It feeds on the fruits of native plants and plays a vital role in seed dispersal.

"If the puaiohi go, then what is going to disperse the fruits and seeds to help this forest re-generate these beautiful fruiting plants that are so much a part of the Hawaiian forest?" she asks.

There is one bird that's doing slightly better. Back in the forest, Crampton uses her best elepaio bird call to see if she can find one.

"They are often very curious," she says.

After an hour or so searching for the elusive cinnamon and gray bird, we find the elepaio.

"I told you it would come in to look at us," Crampton says.

It was a mother bird and her young softly tweeting.

A quiet song helping to tell the story of this troubled forest.