By Dessi Sieburth | Western Tanager July/August 2017, Vol 83 No. 6

The beautiful bright red ‘I’iwi can be seen at the Hakalau Forest Wildlife Refuge (photo Jack Jeffrey).

The beautiful bright red ‘I’iwi can be seen at the Hakalau Forest Wildlife Refuge (photo Jack Jeffrey).

The Hakalau Forest is a national wildlife refuge located on the Big Island of Hawai’i. The refuge supports a rich bird habitat for native Hawaiian birds, many of which are endemic to the Big Island. The Hakalau Forest is about 38,000 acres and is located on the Eastern slope of the Mauna Kea volcano. One unique feature of the Hakalau Forest is that it is made up of just two kinds of canopy trees: the ‘ohi’a tree and the koa tree. These trees can grow up to 80 feet tall, and they form a canopy that shades the smaller trees, shrubs, mints, flowers, and ferns that grow below. Native Hawaiian birds rely on the ‘ohi’a and koa trees to forage and nest. There are eleven native Hawaiian bird species living in and around the Hakalau Forest. Of these, six are Hawaiian Honeycreepers that have evolved from a single finch-like ancestor, which arrived on the island over five million years ago. Over time, the finch gave rise to over 50 honeycreeper species, throughout the islands many of which adapted to pollinate and feed on different of species of flowers.

I went to the Big Island from June 3rd to June 9th, and I spent a day at the Hakalau Forest with biologist and birding guide, Jack Jeffrey. Jack Jeffrey has been a biologist at the forest for the past 30 years, and during that time, he played an important role in preserving the forest and its birds. He taught me about the native plants, birds, and the history of the Hakalau Forest. By the end of the day, we had found eleven native Hawaiian bird species, six of which are endemic to the Big Island.

The Hawai’i Amakihi was very common in Hakalau Fores(Photo by Dessi Sieburth)

The Hawai’i Amakihi was very common in Hakalau Fores(Photo by Dessi Sieburth)

It took about two-hours to drive to the forest from Hilo. The forest was fenced in and to enter the refuge, we had to drive though several gates. Usually, the weather in the forest is cool with afternoon rains. The day we went, it was sunny all day. Once we arrived in the forest, we could hear the songs of birds everywhere. The loudest bird was the ‘Oma’o, a grayish brown native thrush.

Notes and sketch of the rare ‘Akiapola’au. It is endangered and has a unique bill. Field notes and sketch by Dessi Sieburth

Notes and sketch of the rare ‘Akiapola’au. It is endangered and has a unique bill. Field notes and sketch by Dessi Sieburth

The most common native birds at the refuge are the ‘Apapane, which are bright red honeycreepers. These birds can be found on all the Hawaiian Islands, with a total population of about 1.25 million birds. We would often see them flying over the trees in small flocks. Another common bird at the refuge was the Hawai’i ‘Amahiki, a yellow honeycreeper. We saw the ‘Amahiki feeding in small groups and singing in the ‘ohi’a trees. To hear an ‘Amakihi, listen to my recording http://ebird.org/ebird/view/checklist/S37469596. Its population totals about a million birds on the Big Island. Another relatively common bird is the wren-like Hawai’i ‘Elepaio. We saw several family groups of the ‘Elepaio, and many of the young were being fed by the adults. Its numbers have remained stable with a population of 235,000 birds. One of the most stunning birds is the ‘I’iwi. It has a bright red body, beak, and legs and black wings. We saw several groups of the ‘I’iwi foraging actively among the leaves high in the canopy. The ‘I’iwi occurs on all the main Hawaiian Islands and has a total population of about 300,000 birds. To listen to my recoding of the ‘I’iwi go to http://ebird.org/ebird/view/checklist/S37423164.

We found three endangered honeycreepers at the Hakalau Forest. The incredible ‘Akiapola’au (‘Aki) has taken the position of woodpeckers in Hawai’i. It has a bill with a long decurved upper mandible and a short straight lower mandible. It uses the lower mandible to hammer into the bark of koa trees to expose insects and get sap. It then uses the upper mandible to get the insects out of the tree. The Aki is one of the few birds that can move the lower and upper mandible independently (like humans, most birds can only move the lower jaw). Only 800 ‘Akis remain, and we were lucky to see and hear two of them working the koa trees. We also saw the beautiful orange ‘Akepa feeding in koa trees and the nuthatch-like Hawai’i Creeper foraging along the trunk of the koa trees. Interestingly, the ‘Aki, ‘Akepa, and Creeper forage together loosely, and often, we saw all three in the same area in the koa trees.

4 Kalij Pheasant Dessi Sieburth

Hawai’i is home to dozens of introduced species from around the world, including this Kalij Pheasant (Photo by Dessi Sieburth)

In addition to native birds, Hawai’i is also home to many introduced species. When Europeans arrived in Hawai’i, they found few birds at low elevations, so they formed a club with the goal to increase the number of species of birds in Hawai’i. They gathered birds throughout the world and brought them to Hawai’i. Many introduced birds, like the Common Myna and Japanese White-Eye, have thrived. Game Birds, like the Kalij Pheasant and Erckel’s Francolin, were introduced to hunt and now roam freely around the island. We do not know yet about the effects of the introduced birds on the native birds’ populations.

5 Japanese White Eye by Beatrix Schwarz

The Japanese White-Eye is an abundant introduced bird (Photo by Beatrix Schwarz)

While the introduced bird species are thriving on the big island, many of the endemic bird populations are declining due to habitat loss, predation, and disease. Much of the islands native habitat has been lost due to grazing. Up until the first humans arrived in the 1000’s, Hawai’i had no native land mammals except bats, but the Polynesians brought pigs and rats, and then European settlers brought cows, sheep, goats, deer and pigs to the island. Large semi-wild populations of these grazers were soon established, and they roamed freely across the island, eating the native plants, including many of the small flowering plants that provide nectar for some of the specialized honeycreepers. The I’iwi’s bill has evolved over millions of years to be shaped exactly like the mint flower whose nectar is one of the I’iwi’s major source of food. Other introduced mammals that are major threats to native birds are rats, cats, and mongooses. They raid bird nests, eating eggs and nestlings. Rats and cats are especially problematic, as they can climb into trees where nests are located. I was surprised to learn that one of the biggest threats to native birds are mosquitos (also non-native), which carry diseases such as avian malaria. With no immunity to these diseases, large numbers of native birds have died after being bitten by mosquitos. Luckily, mosquitos can only live in warmer, lower elevations (below 4500 feet), and they are not present in the upper areas of Hakalau Forest. However, because of rising temperatures, mosquitos are found at higher and higher elevations each year. Some birds found in lower elevation, like the ‘Amakihi and ‘Apapane seem to be developing resistance to avian malaria. The combination of habitat loss by grazers, predation and disease introduced by mosquitos has led to the extinction of eight of Hawai’i’s endemic bird species in the past forty years.

The native goose in Hawai’i, the Nene, has been one of the rare success stories among native birds, photo by Dessi Sieburth

The native goose in Hawai’i, the Nene, has been one of the rare success stories among native birds (Photo by Dessi Sieburth)

One continuing challenge to conservation efforts at Hakalau Forest is a lack of sufficient funding. Hawai’i has 32 endangered bird species, constituting a third of the endangered bird species in the U.S. However, those birds only receive 4% of federal and state funding. The Red-cockaded Woodpecker of the southeast United States receives as much funding as all the Hawaiian native birds combined. However, there is hope, and some of the native birds are increasing in numbers. One of those species is the Nene, an endemic goose. In the 1940s, the Nene was on the verge of extinction with just 40 individuals. Due to an extensive cat and rat eradication and a large captive breeding program, there are now 3,000 Nene in the wild. Many people are now becoming more aware of these threats and trying to help these birds. Recently, the American Birding Association (ABA) added Hawai’i to its regional area, which helps to spread awareness and make people more eager to visit and protect Hawai’i’s birds. Donations to the Hakalau Forest Refuge Management Endowment, which helps protect habitat by building fences, replanting native plants, and removing pigs and predators can be made at: http://www.friendsofhakalauforest.org/donate.

Thanks to Jack Jeffrey for giving the interview and to my mentors Susan and Frank Gilliland for suggesting to go to the Big Island.

To see my entire interview with biologist Jack Jeffrey at the Hakalau Forest National Wildlife Refuge go to: https://youtu.be/VPn0h_yHkNw

To see my entire interview with biologist Jack Jeffrey at the Hakalau Forest National Wildlife Refuge go to: https://youtu.be/VPn0h_yHkNw

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