Wednesday, January 2, 2013

Bulletin 166 - Maui forest birds

The Hawaiian Islands have the dubious distinction of having the most species of birds that have become extinct, of any place in the world. Why is this? As the most isolated archipelago, most native species were endemic to the islands. When the Polynesian settlers arrived from Tahiti about 800AD, the islands were completely forested. The Polynesians brought alien plants and animals with them to the islands and started clearing land for agriculture. It is estimated from fossil remains that 45 species of birds, went extinct in the next 1000 years.

Europeans arrived after 'discovery' of the islands by Captain Cook in 1778. They brought more alien plants as well as sheep, goats, cattle, horses, pigs, dogs, cats and rats. The grazing animals decimated the local flora, and native birds were forced higher on the mountains to find their usual food sources.

As we saw in the last bulletin, many species of shorebirds migrate back and forth from Hawaii to other continents. These birds carry diseases like avian malaria and avian pox. However, there were no native mosquitoes on Hawaii to transmit the disease to the local birds. In mid 1800s, there was a release of mosquito larvae from a ship's water tanks. This spread these diseases to the local birds who had no natural resistance at all. Fortunately, the mosquitoes breed only up to about 3000' elevation, so on those islands with tall mountains, (Kauai, Hawaii, Maui) there remained disease free areas still.

A further 25 species have gone extinct since the settlement by Europeans. Several species have become extinct in the last 20 years and some other critically endangered ones, are being bred in captivity in attempt to preserve them. For further reading and pictures of these beautiful birds that are gone forever, see this page.

On Maui, the only place to see some of these remaining rare birds is Hosmer Grove and the Waikamoi Preserve managed by the Nature Conservancy. Both places are in Haleakala National Park. I was fortunate to get the services of a docent to take me into the Nature Conservancy preserve, as access is severely restricted.

2 birds in the latest guide book by the Hawaii Audubon Society (2005) edition are extinct..the Poouli, and Nukupuu were last seen on Maui in the 1990s. so the rarest bird left is the Maui Parrotbill (population estimated about 500) which I did not see. The docent says he finds them about once a month making 2-3 visits per week.

The Akohekohe (Palmeri dolei) or Crested Honeycreeper is the 2nd rarest extant Maui endemic with a population estimated at 3,500 birds. It is a 7" predominately black bird with reddish orange nape of neck and similar colored spots on flanks. It was a cold raining day on my visit, but I did see a single bird and got 1 quick photo. A lifer for me, as I missed it on previous visits to Maui. I need to return to get a better photo!

The Maui Alauahio (Paroreomyza montana) is also known as the Maui Creeper. It is a Maui endemic bird that is fairly common in native trees. It is yellow (male) to olive green (female).

Maui Alauahio - male
The Maui Amakihi (Hemignathus virens wilsoni) is an endemic subspecies of the Hawaii Amakihi and potential split, as the Amakihi complex was recently split in to 3 species. It is fairly common and unlike the other native birds, does frequent non-native trees. This photo was taken at the Hosmer Grove campground, not in the preserve. It is olive with black lores and curved bill.

Hawaii Amakihi - Maui subspecies
There are 2 red birds with black wings that occur on all the main islands. The Iiwi (Vestiaria coccinea) is often illustrated in books on Hawaii due to its remarkable curved red beak. It is completely red below. The sexes are similar. Here it is on an ohia blossom, a favorite food source and a good place to watch for this bird.

In contrast, the Apapane (Hematione sanguinea) has a short black beak and white belly. It also visits ohia blossoms. This is an adult. The juveniles are olive green.

Apapane - adult
Lastly, no photo tour of Maui would be complete without a picture of the Haleakala Silversword (Argyroxiphium sandwicense). This plant, a member of the daisy family is found in Haleakala National Park at elevations of 7000 feet to the summit at 10,000 feet on the volcano.

Haleakala Silversword
Happy birding and photography,

David McDonald

photos copyright 2012 David McDonald

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