|Koa-Ohia forest at Hakalau Forest National Wildlife Refuge, one of the best places for seeing native forest birds on the island of Hawaii.|
I have recently posted on the many introduced species on the island of Hawaii, including both the game birds and the songbirds. While it is tempting to add a series of additional posts on native shorebirds, endemic subspecies, fish, mammals, reptiles, etc., this is a busy time of year for me and I'm realizing I might not get to those. So, I want to jump straight to my favorite organisms on the Big Island, and the group that is probably of the most interest to the readers of this blog: the native forest birds.
Because Hawaii is separated from the nearest continents by thousands of miles, many species have evolved only on the Hawaiian Islands, and some of those are found only on individual islands. Most of these species have evolved in the unique forests of the Hawaiian Islands. One of the more iconic endemic forest birds is the Hawaiian Hawk, also known as the I'o. The I'o is a species in the genus Buteo
, and its closest relatives are the Galapagos Hawk, the Short-tailed Hawk, and Swainson's Hawk. It comes in two color morphs, dark and light.
|A light morph Hawaiian Hawk soars over the highway south of Kona. (Digital composite)|
|Dark morph Hawaiian Hawk perched in the rain in Hawaii Volcanoes National Park.|
Hawaii also has an endemic lineage of flycatchers in the old-world family Muscicapidae. Species in this group that might be familiar to North American birders include the Northern Wheatear and the Bluethroat. Hawaii's flycatchers radiated into several species, each limited to one or a few islands. On the Big Island, there is only one species, and it is only found there: the Hawaii Elepaio. The Hawaii Elepaio is unique because it has further differentiated into three distinct subspecies on the island. I was able to see two of the three subspecies, but only one is shown here.
|Hawaii Elepaio, Hilo subspecies, along the Pu'u O'o Trail.|
|Hawaii Elepaio, Hilo subspecies, at Hakalau Forest National Wildlife Refuge.|
Several species of thrush evolved on the Hawaiian Islands, but only one of them is still common today, and several are extinct. The Omao is the most common of these endemic thrushes, but its range is limited to the island of Hawaii.
|Omao, a species of thrush that is endemic to the island of Hawaii, along the Pu'u O'o Trail.|
As cool as those three species are, the species that get people really excited about birding Hawaii are the native honeycreepers. Hawaiian honeycreepers have been considered their own family, Drepanidae, but most ornithologists now consider them to be a subfamily, Drepanidinae, within the finches, Fringilidae. Whatever you call it, this group of species is one of the best known examples of an adaptive radiation. About 4 million years ago, a species of rosefinch somehow managed to colonize the islands from Asia. Finding many open niches on the islands, it rapidly evolved into more than fifty unique species. Sadly, these species started disappearing with the arrival of the Polynesians around 400 A.D., and their extinctions accelerated after Captain Cook's arrival in the late 1800s. Now, only about 17 of these species remain, and 15 of those are considered endangered or vulnerable.
If you want to see native Hawaiian honeycreepers, and you can only visit one island, Hawaii is a good choice. It has a higher diversity of native birds than any of the other islands, and is still home to seven honeycreepers, four of which are found only on that island and nowhere else in the world. I was fortunate to be able to find six of of the seven species, missing only the Akepa
. Here are the six I did see, in order of approximate increasing rarity.
The most common Hawaiian honeycreeper on the Big Island is probably the Hawaii Amakihi, also known as the Common Amakihi. This species is found on only the Big Island and nearby Maui, although the two are considered separate subspecies. There is some evidence that this species has been able to evolve resistance to the avian malaria that has killed so many native birds, giving hope for the future of this species and others.
|Female or immature Hawaii Amakihi on Ohia lehua flower |
|Male Hawaii Amakihi on mamane flower|
The second most common honeycreeper was, in my experience, the most camera shy. The Apapane is a red bird that, together with the Hawaii Amakihi, is one of only two species of Hawaiian honeycreepers that are considered of "Least Concern." This is also the only species that is still found on all the main Hawaiian islands.
|Apapane on Ohia lehua.|
The Iiwi is probably the most emblematic of the Hawaiian honeycreepers. To me, and probably to many others, this species screams "Hawaiian honeycreeper!" They are also still fairly common on the island of Hawaii, although not doing so well elsewhere. Recent reports have detailed dramatic declines on Kauai, and the species is nearly gone from Oahu. This species also has a remarkable voice
, sounding something like a robot to me, to accompany its remarkable appearance.
|Iiwi in the rain near Hakalau Forest NWR.|
Alright, now we're getting to the real goodies. . . . All three of the remaining species are found only on the island of Hawaii, and have been known from only there in historical times. The next bird, the Akiapolaau, is probably the most remarkable remaining honeycreeper in terms of its unique bill adaptation. It fills the niche of a woodpecker, using its straight lower bill to peck holes in wood, and its long, curved top bill to then extract insects from those holes. There are only a few thousand of this species remaining.
|Akiapolaau, adult male, along the Pu'u O'o Trail.|
Although it is not the rarest species, the Hawaii Creeper was the hardest for me to find. For one, they look very much like the common Hawaii Amakihi. (They can be told by their straighter bill, paler throat, more extensive dark mask, and distinctive call note.) Second, the best place to find them is in the Hakalau Forest NWR, which requires reservations and a four-wheel-drive vehicle to reach. Third, they're just not very common. There are still a few thousand of them left, but they are one of the least commonly observed species on the island because they are hard to get to and hard to identify. Only after searching for several hours in the rain was I able to finally get some decent shots of this species, and only after getting the shots was I really convinced I had seen what I was looking for!
|Hawaii Creeper, probably an adult male, at Hakalau Forest NWR.|
|A young Hawaii Creeper in the rain, somewhat more distinctive with its pale throat and fairly obvious pale supercilium.|
Last is the Palila, the only finch-like honeycreeper still living in the main Hawaiian islands. This species, unlike the others, is adapted specifically to the dry forests. It uses its thick bill to crack open seeds of a dry forest tree, the mamane, which is shown here. These seeds are toxic to other species, but the Palila loves them! This was recently thought to be one of the most secure endemic species, but despite a court order in the 1980s for their habitat to be protected from the feral sheep that eat the young mamane plants, their habitat has yet to be protected. This species has declined in numbers by about 80%, following eight straight years of population declines, and is now down to about 1,300 individuals.
|Adult male Palila preparing to zip open a mamane seed pod.|
|Adult male Palila in mamane tree.|
Seeing these rare species was an experience I'll never forget. It was exciting to see them, but I was also left feeling very sad that these species are not getting the protection they need. Because of the isolated nature of Hawaii and the relatively few people living there, these birds do not have the political power they need to garner the protection they require. Hawaii has 45% of the endangered species in the U.S., but receives less than 5% funding allocated to protect endangered species. If you'd like to help save these amazing species, consider making a donation here
Labels: Hawaii, trip reports