Hawaiian Birds and Puaiohi Nest Boxes
The Puaiohi, also known as the Small Kauaʻi Thrush, is endemic to a small part of the island of Kauaʻi and is listed under the Endangered Species Act as Endangered. Puaiohi nest in natural cliff and tree cavities, and like many other native Hawaiian bird species, is highly vulnerable to predation by rats, which prey on eggs, chicks, and even adults. Pigs also destroy native forest understory vegetation where Puaiohi spend much of their time. Non-native plants make their habitat unsuitable, in some cases overwhelming their nesting sites on cliffs and along stream banks with vegetation.
But, there is renewed hope for conservation of the endangered Puaiohi (Myadestes palmeri). The Zoological Society of San Diego has bred and released nearly 200 Puaiohi into the wild since 1999, which has helped maintain the wild population. The Kauai Forest Bird Recovery Project has also placed nest boxes along the Kawaikoi Stream located in the Na Pali-Kona Forest Reserve and the Halepaʻakai Stream in the Alakaʻi Wilderness Preserve, which provide nest sites that are safer from rats, and further bolstering prospects for the species’ recovery.
Nest boxes put up in 2007 by the Kauaʻi Forest Bird Recovery Project have recently resulted in the fledging of a chick. This event is only the second time ever that Puaiohi chicks have fledged from nest boxes in the wild. Furthermore, during checks at the end of the season, fresh nest material was found in three other nest boxes, indicating that Puaiohi have been actively exploring and perhaps using even more nest boxes. When there are only approximately 500 mature individuals of a species left, small successes such as this are reasons to be excited. Photo by Eric VanderWerf.
Plume Award 2011
The 2011 Plume Award was given to the San Diego Zoo Institute for Conservation Research for long-term avian propagation programs and its work with critically endangered Hawaiian birds. The Zoo’s Hawaii Endangered Bird Conservation Program is a species recovery effort in collaboration with the State of Hawaii Division of Forestry and Wildlife and the U.S. Fish and Wildlife Service. The program manages captive breeding facilities at the Keauhou Bird Conservation Center (on the Big Island of Hawaii) and the Maui Bird Conservation Center.
The program has four major focal species, with primary focus on the ‘Alala, also known as the Hawaiian crow. The ‘Alala evolved to be a keystone species of the Hawaiian forest; however, it was almost exterminated by introduced predators, habitat destruction by humans and introduced livestock and avian diseases. The global population of ‘Alala dropped to a low-point of approximately 20 birds in 1994, including the small flock that had already been established in captivity.
The three other focal species are the Puaiohi, or small Kauai thrush, the Palila, and the Maui Parrotbill – all considered critically endangered. The Puaiohi population has rebounded from an estimate of 200 birds to over 500, following the reintroduction of 200 captive-bred Puaiohi into the Alakai Wilderness Preserve in Kauai carried out over the past 12 years. The wild Palila population is currently estimated at just over 1,000 birds, with a major decline observed over the past 10 years. The majority of the Palila population is limited to just one area, making it highly susceptible to extinction due to natural events such as forest fires. The Maui Parrotbill population is currently estimated at about 500 birds, with the majority of the population located in one small area of upland rain forest.
State Of The Birds 2011
According to the new report, State of the Birds 2011, one-third of all birds listed under the Endangered Species Act are native to Hawai‘i, and several of these may already be extinct.
Public lands in Hawai‘i are vitally important, supporting about 73% of upland forest birds. State lands are particularly important for declining forest birds on Kaua‘i, with 78% of species such as Puaiohi and ‘Anianiau.
In the Northwest Hawaiian Islands, 100% of all endangered Laysan Ducks, Laysan Finch, Nihoa Finch, and Millerbirds are under federal management. Nearly 50% of high priority wetlands for endangered waterbirds are federally managed in National Wildlife Refuges.
Recent restoration at Hanalei and Huleia NWRs on Kauai is having a dramatic, positive impact on populations of endangered Hawaiian Duck (Koloa), Hawaiian Coot (‘Alae ke‘oke‘o), the Hawaiian subspecies of Black-necked Stilt (Ae‘o) and Common Moorhen (‘Alae ‘ula), and Nene (Hawaiian Goose).
Hawaiian Birds and Puaiohi Success
The Hawaii Endangered Bird Conservation Program released 12 captive-bred Puaiohi (Kauai thrush) into the Alakai Wilderness Area of Kauai. This was the program’s 13th release in 12 years, and brings the total number of captive-bred Puaiohi released to 200. The Puaiohi (Myadestes palmeri) is found only on the Hawaiian island of Kauai, and is now restricted to habitat within the Alakai Wilderness Area. Survey teams currently estimate the surviving population of wild puaiohi to be around 500 individuals, which is twice the population that was estimated in the late 1990s.
Following each captive-breeding season they decide which puaiohi to release and which to keep, based on genetics and demography. After they are selected, each bird receives a physical examination and blood screening to ensure proper health and fitness for survival in the wild. It is thought that younger birds are less likely to be chased off by resident adults, as their juvenile plumage displays them as non-threatening in established territories. Additionally, young birds have young minds, which are thought to be more flexible in adapting to their new habitat and wild food sources.
Upon arrival on Kauai, the puaiohi were transported to the release site, where they settled into their acclimatization aviaries. Over the next week the birds experienced the new sights and sounds of the surrounding Kauai forest, sampled some of the local food (native berries such as lapalapa and pilo), and grew accustomed to the Alakai weather. Then, the 12 eager Puaiohi were released and excitedly “attacked” the surrounding plant and invertebrate populations, foraging on juicy berries and scavenging through tree bark and moss clumps for tasty insects. Most of the birds left the area to explore other parts of the Alakai, although two birds remained faithful to the area around the release.
Hawaii Endangered Bird Conservation Program
The Hawaii Endangered Bird Conservation Program aims to use captive propagation and release techniques to re-establish populations of critically endangered birds. This program is a unique collaboration between the San Diego Zoo, government agencies, and private landowners, with captive breeding facilities at the Keauhou and Maui Bird Conservation Centers.
Hawaiian birds have exhibited a staggering array of adaptations to their unique habitats resulting in species that are found nowhere else on the planet. Before the arrival of humans, endemic birds were abundant from mountain forests to rain forests by the sea. Unfortunately, of the more than 140 native species and subspecies that were present prior to humans, more than half have been lost to extinction. Among the remaining endemic birds, thirty are federally listed as endangered, and fifteen of these are literally on the brink of extinction, numbering fewer than 500 individuals.
The Hawaiian Crow (‘Alala) has not been seen in the wild since 2002, and the entire known population exists of around seventy-five birds managed at these two locations. Their goal is to increase the captive population and eventually re-establish the population in wild, protected habitat. Unlike many other bird species that have become extinct in Hawaii, this safety net represents a significant step toward the prevention of its extinction.
Three other critically endangered species being focused on are the Puaiohi, Maui Parrotbill, and Palila. Since 1999, more than three hundred Puaiohi have been hatched and two hundred released back into the Alaka`i Wilderness Preserve on the island of Kauai. During this time, the wild population estimate for puaiohi has doubled to approximately 500 birds. Successful trial releases of the Palila have been undertaken on the northern slopes of Mauna Kea, giving great hopes for future population recovery. Additionally, more than 400 Nene from the two facilities have been released throughout the Hawaiian islands.
State Of The Birds 2010
The 2010 State of the Birds report examines one of the greatest environmental challenges of our time – climate change. Climate change threatens hundreds of species of birds already under stress from habitat loss, invasive species, and other environmental threats. The report shows how climate changes will have an increasingly disruptive effect on bird species in all habitats, with oceanic and Hawaiian birds in greatest peril. Climate change is altering the natural world as we know it, and this report calls attention to the collective efforts needed to protect nature’s resources for the benefit of people and wildlife.
Oceanic birds (including albatross, tropicbirds, frigate birds) are among the most vulnerable species because they don’t raise many young each year, they rely on rapidly changing marine ecosystems, and they nest on islands that may be flooded as sea levels rise.
Hawaiian birds such as Puaiohi face multiple threats and are increasingly challenged by mosquito-borne diseases and invasive species as climate change alters their native habitats. On the main Hawaiian Islands, avian malaria and pox spread by introduced mosquitoes pose a significant threat to native Hawaiian birds, which have little natural resistance to these diseases.
Typically around 5,000 feet above sea level temperatures are below 55°F, and the malaria parasite will not completely develop in birds. An increase in temperature of only 4°F would raise the 55°F threshold by nearly 1,000 feet, and raise the risk of disease. Warming on Kaua’i would result in an 85% decrease in protected habitat, contributing to further declines among imperiled species such as ‘Akeke‘e and ‘Akikiki.
Birds are excellent indicators of the health of our environment, and right now they are giving us an increased sense of urgency about climate change. We can reduce the impact of climate change by taking immediate action to reduce carbon emissions and find creative conservation solutions to help birds adapt to the changes already in process. If we can help the birds weather a changing climate… we can help ourselves.
