A weekend photography trip from my home on Oahu to the Big Island of Hawaii inspired this diary.
Steam cloud generated by lava flowing into the ocean
The islands of Hawaii are the tops of giant volcanoes that emerged in the middle of the Pacific Ocean over a tectonic hot spot. The Pacific Plate moves slowly to the northwest creating a long chain of island and atolls stretching over a thousand miles across the Pacific. The hot spot is currently situated under the island of Hawaii, the youngest, largest and most volcanically active of the main islands.
Around four or five million years ago a single species of finch found its way to these most isolated of all major island groups. It found a wide variety of open ecological niches and very little competition. Over time this one little species of finch exploded into dozens of species in the world's most spectacular case of avian adaptive radiation. The variations in Darwin's famous finches in the Galapagos Isles pale in comparison to the diversity of form and function displayed by the Hawaiian honeycreepers. (The term honeycreeper derives from the fact that many species feed on nectar ("honey") and their habit of "creeping" over trunks and branches in search of food.)
Snow on cinder cones near the summit of Mauna Kea
Unfortunately, as much as they are a superior example of evolution they are also a textbook case of extinction due to anthropomorphic disruption to an island ecosystem. Before the arrival of those amazing seafarers the Polynesians around 1,500 years ago Hawaii was a bird paradise. There were no mammals other than a couple of species of bats and probably no reptiles (possibly a couple of species of small lizard). Among the wide variety of birds were huge flightless geese, a flightless duck, a flightless ibis, and dozens of species of honeycreepers.
Koa/'Ohi'a Forest
Many species disappeared after the arrival of the Polynesians who ate the flightless birds, altered the landscape to grow crops and farm fish, and who introduced chickens, small pigs, dogs and rats. More devastation followed the arrival of Europeans and their cattle, goats, sheep, large pigs, cats, mongooses, alien birds and, probably worst of all, mosquitoes that carry diseases, such as avian malaria, from which the birds had no immunity. (The Polynesians of course suffered a similar devastation from diseases carried by the Europeans themselves) The mosquito has largely eliminated honeycreepers from all areas below 4,000 ft elevation (the insect cannot breed in the cooler temperatures above that level) Add habitat loss to the alien species and diseases and you have the makings for the disaster that is consuming the honeycreepers.
This area was probably thick forest before the arrival of Europeans.
At least 15 species have gone extinct in historical times and at least four more may have recently disappeared, none having been seen for years. According to one source this is the current conservation status: Critically Endangered: 6 species; Endangered: 5 species; Vulnerable: 7 species; Near Threatened: 5 species. From my count that would include all 23 extant species.
Mauna Kea from Saddle Road
Our guide, Jack Jeffrey, picks us up before dawn in Hilo and we drive up Saddle Road to our first location: a trail through lava flows and koa/'ohi'a forest at around 5,000 feet on the slopes of Mauna Loa. Jack is a wildlife biologist, photographer, tireless hiker, exceptional guide and a great guy. It isn't long before we score our first rare and endangered species:
Hawai'i Creeper Oreomystis mana
This is one of the only honeycreepers that doesn't carry a Hawaiian name. This is probably due to relatively drab appearance and similarity to the more abundant 'Amakihi. (This is not a great photograph due to ghosting from the slow shutter speed. Shooting these rapidly moving little birds in the changing light of the forest is a definite challenge. Many of the shots included in this diary are extreme crops and are not usable for printing.)
It feeds chiefly on insects it finds by creeping along tree trunks. They are endangered and number only around six thousand individuals. Their habit of building nests close to the trunks of trees may make them exceptionally vulnerable to rat predation.
ʻElepaio Chasiempis sandwichensis
The active and bold 'Elepaio was easier to photograph, coming in close to check us out in response to Jack's expert calls. They are agile birds that fill the niche of flycatcher, often feeding on insects on the wing. The Hawai'i 'Elepaio is not considered endangered but the Oahu subspecies is a listed bird.
'Akiapola'au Hemignathus munroi
This highly endangered bird is maybe the most interesting honeycreeper because of its amazing mismatched bill. The "Aki" fills the niche that would otherwise be occupied by woodpeckers. The lower mandible is stout and used to find hollows and peck holes in the wood. The long curved upper mandible is used to extract the prey. Both the upper and lower mandibles articulate and can also be used as tweezers.
The "Aki" is only found on the island of Hawai'i.
They may number as few as 1,500 individuals.
We hike back to the truck and drive to the second location, a dry mamane forest high on the southwest slopes of Mauna Kea at around eight thousand feet elevation. Jack is tireless but by this time my feet are sore from the morning hike on unforgiving lava and my lungs can't seem to get a grip on the thin air. Fortunately we don't go far before Jack hears the call of bird we are seeking:
Palila Loxoides bailleui
This finch-billed honeycreeper lives only in these high dryland forests, feeding primarily on young mamane seed pods. Jack tells us the population seems to be collapsing, dropping from 6,000 to approximately 2,000 over the last several years. The cause is not certain but mosquitoes may be adapting to higher elevations and it is possible that global warming is allowing them to move higher as well. Ongoing habitat degradation by feral sheep and goats is also a problem.
Mamane Flower
We are incredibly lucky to see the three highly endangered species on one day (Creeper, Aki and Palila). In the mamane woodland there are a large number of the much more common...
Hawai'i 'Amakihi Hemignathus virens virens
This bird is a generalist, feeding on insects, fruit and nectar. It also seems to have developed resistance to the mosquito borne diseases allowing them to extend their range all the way down to sea level in some areas of the Big Island. They are easily the most numerous of the extant species of honeycreeper.
Feeding on nectar
Hunting for insects
Here is a photo of a Maui 'Amakihi I shot last year on the slopes of Haleakala at Hosmer's Grove.
On Sunday morning I spend some time on my own unsuccessfully looking for Pueo, the Hawaiian subspecies of Short Eared Owl. We saw a couple from a distance on Saturday but on Sunday I wasn't lucky enough to spot any in the area that Jack recommended.
I decide to drive to another area along Saddle Road that is good for viewing the more common honeycreepers. Along the way I notice a relatively large bird in the top of a tree along the road. It is another life first for me, not a honeycreeper but the only endemic hawk:
'Io or Hawaiian Hawk, Buteo solitarius
There are approximately 3,000 individuals on the island of Hawai'i. They are not found on the other islands. Surprisingly the Fish and Wildlife Service is recommending that they be delisted as endangered or threatened because the population is stable. They have shown resilience and have adapted to human disruptions to the landscape but it seems to me a relatively small population confined to one island would deserve continued protection. There are two public meetings on the island of Hawaii coming up regarding the delisting.
The 'Io has been a representative of Hawai'ian royality or Ali'i, 'Iolani (exalted hawk) was the nickname of two Hawaiian kings (Kamehameha II and IV) and is the name of the royal palace in Honolulu.
After setting up to shoot honeycreepers at my destination I managed to catch another (or possibly the same) 'Io on the wing.
After a couple of hours I only manage to get a few of distant shots of the more common birds I am hunting:
'Apapane Himatione sanguinea
The beautiful crimson 'Apapane is found on all the main Hawaiian islands except possibly Lanai but it is rare on Molokai and Oahu. They primarily feed on 'Ohi'a nectar and insects. While it is relatively common for a honeycreeper I still haven't managed to get a good photo. I got this extreme cropped image Sunday:
And this one last year on Maui.
We will finish with the the possibly the most beautiful and iconic honeycreeper:
'I'iwi Vestiaria coccinea
This symbol of Hawaii is also relatively common and and has a similar range as the 'Apapane, but they are exceedingly rare on Molokai and Oahu. They also feed on the nectar of 'Ohi'a and other flowers as well as small arthropods. I only managed to get this extremely cropped image on Sunday:
Last year on Maui I got these much better images of this stunning little bird:
I hope you have enjoyed this little birding adventure from the Sandwich Isles. I have not covered all species of honeycreepers, but only those I have photographed. If you are more knowledgeable than I and see a blatant factual error please don't hesitate to let me know. I am not proud. As usual feel free to post your favorite images and please be good humans.
Aloha