Hope for the birds

KOKEE — An anianiau with goldenrod plumage flitted across the Alakai bogland — and straight into a delicate net spread across a dozen feet of misty canopy. The net cradled the bird in place like a baby.

Maria Costantini lifted the forest bird, a vulnerable native species found only at high elevations on Kauai, out of the mesh and into her hand. Weighing no more than four pennies, the bird resembled a marshmallow Peeps candy.

Costantini tucked him into a small cloth bag and, using a clothespin, fastened it to the collar of her shirt. A hundred yards down the Pihea trail, in a small clearing protected from rain by a tarp, she removed the bird from the bag and started taking his measurements.

Costantini is a field assistant for Kauai Forest Bird Recovery Project, a state Division of Forestry and Wildlife program that promotes the conservation of Kauai’s native forest birds, all of which are unique to Hawaii, several of which are endemic to Kauai and a few of which are endangered.

The project’s greatest challenge is to fend off the birds’ threats, such as habitat degradation, the spread of invasive plant species and feral predators, like pigs and rats, at a time when new threats are mounting.

With the rise of climate change, mosquitoes are invading terrain at increasingly high elevations. As a result, scientists say mosquito-borne diseases, such as avian malaria, could begin to threaten birds in new landscapes. If the number of disease-free refuges dwindles, forest birds susceptible to malaria, such as the anianiau, could one day find themselves staring in the face of extinction.

Add to that the changing rainfall patterns that climate change is predicted to bring — heavy rains have the important job of flushing out pools of standing water where mosquitoes breed — and the disease forecast for Kauai’s forest birds becomes increasingly complicated.

On a patch of soggy earth overrun with invasive kahili ginger, Costantini held the anianiau upside down. Using pliers, she attached a silver band branded with a unique numeric code around the bird’s wiry leg.

The code on the band is linked to a native bird database maintained by the U.S. Fish and Wildlife Service. Researchers use the data to track migration, population growth and movements of individual birds and entire species.

Costantini clamped three more bands around the anianiau’s legs. These red, white and blue tags are linked to a local database that helps birders and researchers identify the individual birds they see by the color combination of bands on their legs.

“A patriotic bird,” Costantini announced, rotating the animal right-side up.

Next, Costantini blew a steady stream of breath at the bird’s chest, parting the feathers to reveal yellowish deposits of stored fat. She jotted down a visual estimation of the bird’s overall body fat percentage — a healthy amount, showing no signs of starvation.

She checked the bird for signs of molting. There were none. She checked for flight feather wear and found nearly no damage. No fraying, no nicks.

“These are actually really nice, really pretty,” Costantini said, fingering through the feathers that make up the wing. “When they first put out a new feather there’s a beautiful glow to it that tells you it’s brand new. These aren’t brand new, but they are in really good condition.”

Finally, Costantini extracted a tiny amount of blood from a vein in the wing. The blood will be tested for avian malaria. Among Kauai’s forest birds, honeycreepers like the anianiau are among the most susceptible to malaria.

Through it all, the bird stayed largely still. He didn’t make a peep.

Like many of Kauai’s forest bird species, the anianiau once thrived island-wide. But over time, as humans cleared and degraded forest bird habitats to make way for mankind, the species began to struggle. At least five native forest bird species have gone extinct and the remaining species have retreated to forests at Kauai’s highest elevations.

Although its range and population has declined in the past 100 years, the anianiau is thought to be stable in its remaining habitat within the forests of the Kokee, Waimea and Alakai regions — at least right now it is.

Kauai is not a very high island compared to Maui or Hawaii, according to Lisa “Cali” Crampton, Kauai Forest Birds project manager. So the increasing appearance of mosquitoes at higher elevations is happening faster here. As a result, more native birds have been exposed to malaria.

From 2009 to 2013, a higher percentage of forest birds tested positive for the disease than during the late 1990s, Crampton said.

“We have seen dramatic declines in the abundance of all six native honeycreeper species on Kauai,” she said. “But we cannot say for sure that this is due to the increased prevalence of malaria, although we hypothesize that disease is a leading cause of these declines.”

But it’s not all doom and gloom, Crampton said.

“I see hope,” she said. “I definitely see hope for several of the species because they are not as affected by disease as much. They’re affected by some of the other things that are easier for us to deal with because we have the tools. Even on the mosquito front, I think that down the road we will have the tools. It sounds like we could be three to five years away from some breakthrough stuff.

“These birds face a lot of threats and it is complicated, but I do see hope for many of them.”