Aloha State News

(KAʻŪ FOREST RESERVE, HAWAI‘I ISLAND) –  ‘Io, the Hawaiian hawk, is the subject of simultaneous research projects underway on Hawai‘i Island. It’s one of two raptors native to Hawai‘i. The other is Pueo, the Hawaiian short-eared owl. ‘Io research is being conducted by the DLNR Division of Forestry and Wildlife (DOFAW) and San Diego Zoo Wildlife Alliance (SDZWA) and is giving conservationists new insights into the majestic birds’ range and behaviors.

For the DOFAW ‘io research team, “forestry” is not exactly in their job descriptions.  Yet, earlier this month, trying to reach locations in the Ka‘u Forest Reserve to attract, trap, and band ‘io, Kate Maley and Bri Bishop encounter a half-dozen trees blocking their way. To get to the “wildlife” focus of their jobs they use a hand saw and machetes to clear the road. It is an inauspicious start to the day.

“Once we get to a location we think is good ‘io habitat, we begin playing back ‘io calls to attract birds,” Maley explained. The screech of an ‘io sounds through the canopy for eight minutes while the pair scans the sky. When they don’t spot a bird in that time frame, they move onto another location and try again. Third time is a charm.

Shortly after playing calls, an ‘io flew into the area to investigate. While Bishop prepared a cylinder-shaped wire trap, with a lure inside, the ‘io perched high on a branch, peering down through the limbs. The trap is placed on the ground and within minutes the bird swoops down thinking it’s going to get an easy meal. Instead, it’s talons are caught by the trap and Maley rushes over to free it and begin several hours of processing.

The adult female is the seventh bird captured since the DOFAW study began last fall. The SDZWA research in the Pu‘u Maka‘ala Natural Area Reserve has resulted in six birds caught, banded, and now being tracked.

A species recovery project, aimed at reintroducing ʻalalā (Hawaiian crow) back into the wild, failed, with ‘io shouldering some of the blame. It’s believed the hawks attacked numerous crows and the remaining ‘alala were subsequently recaptured. Plans are underway now to try again on Maui, where there are no ‘io. The current research is expected to provide invaluable data for another ʻalalā introduction project on Hawai‘i Island in the future.

“So far, we’ve gotten some cool data that show ‘io using the habitat on the edge of the Kaʻū Forest Reserve and in the pastures. They seem to be using this edge habitat, moving into the forest sometimes, sometimes hanging out in the pastures and sometimes flying all the way to coffee plantations around Pāhala,” Maley said.

How do researchers know this? Each bird is weighed, measured, gets an overall health check and a leg band. Much of the team’s time with bird-in-hand is spent attaching a tiny GPS tag to its back. A leather hood helps keep the bird calm during the procedure. The tags use cellular tracking technology, and the researchers can pinpoint each ‘io’s location at any given point in time, by simply looking at colored bird-specific data points on their phones or computers.

“That’s one thing that’s cool about the work we’re doing here. Eventually it’s hoped ʻalalā will be released again and knowing where the ‘io are spending their time and how they’re utilizing the landscape will help identify places where there’s not much ‘io presence,” Maley added. “Between what we’re doing, what the zoo wildlife alliance is doing, and past efforts by the U.S. Geological Survey, we’re going to develop a really impressive data set.”

Original source can be found here.