Hawaiian Birds and Nihoa Millerbird Success
Endangered Nihoa Millerbirds were reintroduced to Laysan Island in 2011, after a 100-year absence, and are now breeding there. These tiny Hawaiian songbirds were relocated in a bold effort to initiate a second population and minimize the risk of extinction. Biologists monitoring the birds have just reported that some of the birds have laid eggs, and some of these eggs have now hatched.
The Nihoa Millerbird (Acrocephalus familiaris kingi) made an unsuccessful out-of-season breeding attempt shortly after their arrival. Now the birds are entering their first proper breeding season, and nest building activity was observed in February, and the first eggs in March. This first-ever opportunity to observe Millerbird breeding from start to finish and collect behavioral and life-history data throughout the season is a significant advance in the study of this endangered species. The next important milestone for Millerbirds on Laysan will be when chicks fledge and forage on their own. Following that, the project team will be looking for this first generation of Laysan-hatched birds to begin breeding themselves.
The first Millerbird translocation to Laysan Island, which is within Hawaiian Islands National Wildlife Refuge and the Papahanaumokuakea Marine National Monument, was the result of many years of research and detailed planning by biologists and resource managers. By creating a second population of Millerbirds on a second, distant island, the translocation project will reduce the chances that catastrophic events on Nihoa, such as hurricanes or the introduction of predators, will drive the Millerbird to extinction. Plans are already underway for a second translocation to ensure that the Laysan population has a solid foundation to build upon.
Hawaiian Birds and Bryan’s Shearwater
After decades of research, scientists have confirmed thru DNA a unique specimen among the other known species of Shearwaters. Most of the more than 9,000 known bird species, including twenty-one Read more
Hawaiian Birds and Short-tailed Albatross Success 2
An endangered Short-tailed Albatross has nested in the United States and produced a chick for the second time ever recorded. The recent discovery of the nest and chick on Midway Atoll in the Northwestern Hawaiian Islands follows the fledging of the first U.S.-born chick last year at the same site by the same parents. This news suggests that the first chick hatched last year was not an isolated incident, and this may be the early stages of the formation of a new population of this very rare bird.
The Short-tailed Albatross (Phoebastria albatrus) was once the most abundant albatross species of the North Pacific, numbering more than a million birds. Feather hunters decimated the population around the turn of the century, however, and researchers believed by the 1940’s that the species had gone extinct. In the early 1950s, ten pairs were discovered breeding on the volcanic island of Torishima, Japan, and they have grown to 3,000 individuals.
Midway Atoll is home to the world’s largest colonies of Laysan and Black-footed albatrosses, as well as millions of other seabirds. 55 miles from Midway, another Short-tailed Albatross pair is attempting breeding on Kure Atoll, the northern-most coral atoll in the world. Both Midway and Kure are part of the Papahānaumokuākea Marine National Monument. Albatrosses tend to be faithful to the place of their birth, returning when they are around 8 years old to rear their own young. So it will be several years before researchers find out whether or not a full-fledged short-tailed American colony is in the making.
Hawaiian Birds and Hawaiian Honeycreepers
Smithsonian scientists have determined the evolutionary family tree for one of the most strikingly diverse and endangered bird families in the world – the Hawaiian Honeycreepers. The researchers determined the types of finches that the honeycreeper family originally evolved from and also linked the timing of that rapid evolution to the formation of the main Hawaiian Islands. Using genetic data from 28 bird species that seemed similar to the honeycreepers morphologically, genetically or that shared geographic proximity, it was determined that the various honeycreeper species evolved from Eurasian rosefinches.
There were once more than 55 species of these colorful songbirds, and they are so diverse that historically it wasn’t even entirely clear that they were all part of the same group. Honeycreepers probably represent the most impressive example of an adaptive radiation in vertebrates that has led to a number of beak shapes unique among birds. Some eat seeds, some eat fruit, some eat snails, some eat nectar. Some have the bills of parrots, others of warblers, while some are finch-like and others have straight, thin bills.
Hawaii’s unusual geology played a role in the rapid evolution of many honeycreeper species that followed. The volcanic islands have formed one by one over time, as the Pacific tectonic plate is dragged across a “hot spot” of magma, and each new island provided a new opportunity for colonization. Each island that forms represents a blank slate for evolution, so as one honeycreeper species moves from one island to a new island, those birds encounter new habitat and ecological niches that may force them to adapt and branch off into distinct species.
The researchers looked at the evolution of the Hawaiian honeycreepers after the formation of Kauai-Niihau, Oahu, Maui-Nui and Hawaii. The largest burst of evolution into new species, called a radiation, occurred between 4 million and 2.5 million years ago, after Kauai-Niihau and Oahu formed but before the remaining two large islands existed, and resulted in the evolution of six of 10 distinct groups of species characterized by different sizes, shapes and colors.
Endangered Hawaiian Waterbirds Conservation
The Hawaiian Common Moorhen, Hawaiian Coot, and Hawaiian Black-necked Stilt have been listed under the Endangered Species Act for over 40 years, but these three endemic and endangered Hawaiian waterbirds are showing increasing populations. The three birds all reside exclusively in Hawai’i in low elevation wetlands. Their populations have been impacted by wetland loss, invasive plants, and introduced predators such as rats, cats, dogs, mongoose, and bull frogs. A study identified larger population increases on islands where wetlands were being protected (Oah’u and Kaua’i) and little or no population increases on islands containing few wetlands and/or less protection (Hawai’i and Maui).
The Hawaiian Coot (‘Alae Ke‘oke‘o) continues to be found on many of the larger islands and with a population estimate of up to 5,000, it is the most abundant of the three birds but it also has the most variable populations, year to year. Hunting depleted populations in the early 20th Century. It is 15 inches with a white bill topped by a frontal shield which is usually white, but can vary from bluish white to yellow to dark blood red. They have white undertail feathers that are seen when swimming or during their courtship displays.
The Hawaiian Black-necked Stilt (Ae’o) is found on Hawai’i, Kaua’i, Maui, Moloka’i, O’ahu, and Ni’ihau, and more recently, on Lana’i. Some reports indicate the bird was common in some locations in the late 1800s but by 1900 had become scarcer. By 1940, only 200 were believed to exist. The most recent survey estimates a population of about 1,500 birds. It is a slender wading bird that grows up to 15 inches in length, with a black back and white forehead, and white below; the female has a tinge of brown on its back. It has very long pink legs and a long black bill.
The Hawaiian Common Moorhen (‘Alae ‘Ula) population is the smallest of the three, numbering as few as 30 in 1970. The total current population is estimated to be in the low 100s. The bird historically inhabited all of the larger islands, but now inhabits only O’ahu and Kaua’i. The 13-inch-long moorhen is dark gray with a black head and neck, and white feathers on its flanks and on its undertail feathers. It has a very distinctive red frontal shield above its yellow-tipped bill. Its legs and feet are greenish.
Management actions are being implemented at places like Hanawi Natural Area Reserve on Maui, and Hakalau Forest National Wildlife Refuge on the island of Hawai’i. Given the long-term trend in the Hawaiian Islands of losing wetland habitat from unprotected areas, protected refuges and conservation easements on private land continue to be critically important to recovering the islands’ endangered waterbirds.
Hawaiian Birds and Nihoa Millerbird Relocation
Nihoa Millerbirds are endemic to Nihoa Island, where the population has dwindled to between 500 and 700. Two dozen endangered Nihoa Millerbird have been moved from Nihoa Island in the Northwestern Hawaiian Islands to Laysan Island 650 miles north in the hope they will establish a new population and prevent the extinction of the species.
The Nihoa Millerbird (Acrocephalus familiaris kingi), which weighs less than an ounce, is a lively brown song bird that forages for insects among low shrubs and bunch-grasses. Introduced domestic rabbits denuded Laysan’s vegetation between 1903 and 1923, drastically altering habitat and driving some endemic species, including Laysan Millerbird, Laysan Honeycreeper, and Laysan Rail, to extinction.
A team of wildlife specialists arrived by boat, captured birds at Nihoa and selected one dozen males and one dozen females for transport to Laysan. The birds were loaded onto a research vessel for a three-day boat trip to Laysan Island, where researchers believe the birds face no imminent threats and are suited for the ecosystem. Each bird carries a unique combination of colored leg bands to allow identification in the field, and half the birds were fitted with temporary radio transmitters so that their locations can be determined during their first three weeks in their new home.
The birds were released to their new home, and quickly began feeding on flies and spiders. The males began singing loudly to demarcate their territory to other males. The females, meanwhile, were observed fluttering their wings, which is a sign they’re interested in a male bird’s territory and the male bird. Biologists will remain on Laysan for the next year to monitor the birds’ movements, behaviors, and hopefully their first nesting attempts. On Laysan, the Millerbird joins other endangered species, such as the Laysan Finch, Laysan Duck, Hawaiian Monk Seal, and several plant species, as well as millions of nesting seabirds.
