Hawaiian Petrel Burrow With Chick Found on Kohala Mountain

Hawaiian Petrel chick found in burrow in the Kohala District. (PC: DLNR/DOFAW)

An endangered Hawaiian Petrel (‘ua‘u) burrow and a baby chick were found inside the Pu‘u O Umi Natural Reserve Area on Kohala Mountain. This discovery provides the first documentation of a new ‘ua‘u colony endemic to the Kohala district.

The Department of Land and Natural Resources Division of Forestry and Wildlife discovered the burrow in late October.

“This was a long work in progress. A few years ago, we began hearing ‘ua‘u calling at night while constructing watershed fencing in remote parts of Windward Kohala,” said Alex Wang,Endangered Forest Bird Field Supervisor for DLNR/DOFAW. “While this indicated ‘ua’u were breeding in the area, we didn’t get confirmation until a month ago when we found the burrow and the chick. When I joined the program in 2016, I began trying to find exactly where they breed.”

Wang says the quest was made difficult because the area is extremely remote, and he and others only had access a few times each year.

During their visits, the team began using night and infrared vision devices to try and see ‘ua’u. They deployed remote acoustic devices, called song meters, that are left in the field for months at a time in an attempt to narrow down their search area. That led them to begin focusing on the back rim of Waimanu Valley. With additional night surveys they began searching areas believed to possibly have high burrow activity.

“As with many of our endangered bird projects, we began collaborating with experts in the field, from organizations like Pacific Rim Conservation and the Kaua‘i Endangered Seabird Recovery Project to try and help us further pinpoint possible ‘u‘au burrows,” said Nick Agorastos, the NAR manager on Hawai‘i Island. “They told us the habitat looked excellent, but it was a vast area and was akin to searching for the proverbial needle in a haystack.”

Experts began utilizing lights to attract adult Hawaiian petrels on a moonless night, they trapped two birds in mist nets and surgically implanted specialized GPS tracking tags onto their backs. The GPS trackers give researchers a fix on the birds every four minutes.

“We were only able to get data from one of the birds and unfortunately it was a non-breeding ‘u‘au,” Wang said. “So, in August of this year we tried again and successfully tagged four birds.”

So far, the team has only gotten data from one of the birds, but its “tracks” led them straight to the burrow, in which they found the chick on Oct. 28. Plans are underway now to develop a plan to manage the unique population of the endangered species at Kohala, including reducing any threats they’re facing.

“With the recent challenges associated with the reintroductions of other endangered birds like the ʻAlalā and the kiwikiu, this is the kind of positive news we need to bolster the continued efforts of endangered bird programs across Hawai‘i and to lift the spirits and hopes of all the passionate and dedicated people working to restore their rightful place in our forests,” Agorastos said.